US3677255A - Electrical ignition system - Google Patents

Abstract

An automotive ignition system in which a storage condenser or capacitor is charged during the time that the points or contacts are closed, the condenser or capacitor being charged from a source of DC energy through a power supply circuit that steps up the voltage.

Description

United States Patent Withem 1 July 18, 1972 ELECTRICAL IGNITION SYSTEM References Cited 72 Inventor: Donald 1). Withem, Chagrin Falls, 01110 UNITED STATES PATENTS 3,131,327 4/1964 Quinn ..123/148 E 0st [73] Assgm Elem 3,263,124 7/1966 Stunner 123/148 E [22] Filed: Feb. 18, 1971 3,312,211 4/1967 Boyer ..123/148 E 3,312,860 4/1967 Sturm... .....123/148 E [21] 1 3,318,295 5/1967 Byles ..123/148 E Related US Application Dam 3,415,234 12/1968 Dammann ..123/ 148 E [63] Continuation-impart Of SCI'. NO. 871,672, NOV. 19, Primary Examiner-Laurence M Goodridge 1969, which is a continuation of Ser. No. 767,915, Anomey-Woodling,Krost,Granger&Rust Sept. 30, 1968, abandoned, which is a continuation-in- 1 part of Ser. No. 570,845, Aug. 8, 1966, abandoned. [57] ABSTRACT An automotive ignition system in which a storage condenser [g2] (g1 ..123/148 1% or capacitor is charged during the time that the points or com lug/209 tacts are closed, the condenser or capacitor being charged from a source of DC energy through a power supply circuit that steps up the voltage.

57 Clainm, 14 Drawing figures Patented July 18, 1972 6 Sheets-Sheet l /LEI? m Fig. I

Fig. 2B

INVENTOR. DONALD D. W/THEM J 75 M 47614. ATTORNEYS.

Patented July 18, 1972 3,677,255

a Sheets-Sheet 2 IN\-ENTOR. DONALD D. W/THEM a. -vz -w n-r'rorewev's Patented July 18, 1972 6 Sheets-Sheet 4 INVENTOR. DONALD 0 W/THEM BY M7 T'VJ/ A TTOENE Y5 Patented July 18, 1972 3,677,255

6 Sheets-Sheet 5 INVENTOR DONALD .D. W/THEM fin .17

ATTORNEYS Patented July 18, 1972 6 Sheds-Sheet 6 Fig. 13

Fig. /2

INVENTOR. DONALD D, W/ THEM BY I 774:,

93mm: xx f ATTOENEYEI ELECTRICAL IGNITION SYSTEM This application is a continuation-impart of my application Ser. No. 871,672 filed Nov. 19, 1969, which was a continuation of my application Ser. No. 767,915 filed Sept. 30, 1968, now abandoned, which in turn was a continuation-in-part of my earlier application Ser. No. 570,845 filed Aug. 8, 1966, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to ignition systems of the condenser discharge type for igniting the combustible mixture in internal combustion engines.

It is an object of this invention to provide an ignition system of the condenser discharge type wherein energy is transferred from a direct current source through a transformerinto a condenser by a unique and novel manner which results in a flexibility in the design of practical ignition systems.

It is another object of this invention to provide an ignition system for internal combustion engines whereby the energy drawn from a direct current source or battery is substantially proportioned to the rotative speed of the engine resulting in a considerable saving of energy at the lower rotative speeds of the engine. This is an especially good feature when the engine is being started up for at this time the starter electric motor places a heavy demand on the direct current source or battery.

Another object is to provide a circuit wherein energy consumed by the transistor of the circuit during the time said transistor switches from a conductive state to a non-conductive state is considerably reduced, resulting in the transistor being operated at cooler temperatures.

Another object is to provide a circuit wherein due to the position of the transistor in the circuit the transistor is more difficult to destroy by accidental physical shorts.

Another object is to provide an ignition coil or transformer of a new design or principle embodying my invention for firing the spark discharge device or sparkplug of the engine.

Other objects and a fuller understanding of this invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, in which:

FIGS. 1,3,4,5,6,7,8,9,10 and 11 are complete schematic drawings, and FIGS. 12 and 13 are partial schematic drawings, of ignition systems made in accordance with my invention;

FIG. 2A illustrates graphically and generally how certain currents vary with time. These certain currents are: the current charging condenser or capacitor 26 in FIGS. 1, 4 and 6; the current flowing in winding 22 of FIGS. 1 and 4 and in winding 40 of FIG. 6; and the current flowing in winding 16 of FIGS. l,3,4,5,6,7 and 8.

FIG. 2B illustrates graphically and substantially how certain currents vary with time. These certain currents are the current flowing in winding 22 and inductance 38 of FIGS. 3 and and the current flowing in winding 40 and inductance 38 of FIGS. 7 and 8.

CONSTRUCTION OF FIGS. l,3,4,5,6,7,8,9,10,11,12 AND 13.

Reference numeral 11 refers to a source of direct current or, in the drawings, a battery. Numeral 12 refers to the conventional ignition switch of an internal combustion engine. Numeral 13 refers generally to a P-N-P transistor having a collector electrode 13C, a control or base electrode 138, and an emitter electrode 13E. It should be apparent to those skilled in the art that in some cases an N-P-N transistor could be used for transistor 13. Numeral 14 generally designates a magnetic control device having three windings on a common magnetic core, a primary winding 15 and two secondary windings 16 and 17, respectively. Numeral 18 is a current limiting resistor. Numerals 19A and 19B refer to the standard breaker contacts. Numeral 20 is a cam rotated by the engine which causes breaker contacts 19A and 198 to be opened and closed in synchronism with the operation of the engine in a manner well known to those skilled in the art.

Numeral 21 in FIGS. 1, 3, 4 and 5 generally designates a transformer having a primary or low voltage winding 22 and a secondary or high voltage winding 23. Numerals 24 and 25 are semi-conductor diodes but could be any device that passes current substantially in one direction. Numeral 26 is a storage condenser to be charged and discharged in synchronism with the operation of the engine. As used in this patent application, the terms condenser" and capacitor" are interchangeable as being synonymous. Numeral 27 is a resistor used to dissipate energy in the form of heat. Numeral 28 generally designates a silicon controlled rectifier having a cathode electrode 28C, an anode electrode 28A, and a control or gate electrode 286. However, it is to be understood that a thyratron tube or other appropriate electronic switch device could be used for silicon controlled rectifier 28 without departing from the spirit and scope of my invention.

Numeral 29 in FIGS. 1, 3, 4 and 5 generally designates a standard type ignition coil having a primary of low voltage winding 30 and a secondary or high voltage winding 31. Numeral 32 designates schematically a rotor contact which is caused to be rotated by the engine and in synchronism with the operation of the engine and therefore in synchronism with the operation of breaker contacts 19A and 19B. Rotor contact 32 cooperates with a plurality of contacts 33, in the drawings four are shown, located on a conventional distributor cap 34. For convenience of illustration, one of the four contacts 33 is shown connected to one side of a spark plug 35. The opposite side of spark plug 35 is connected to ground. It will be appreciated that in an actual ignition system each one of the contacts 33 is connected with a respective spark plug or spark discharge device.

The breaker points 19A and 19B illustrated in FIGS. l,3,4,5,6,7,,9,10 and 1 l are for the purpose of illustrating, by way of example, synchronizing means associated with the various embodiments of my invention. The function of breaker points 19A and 19B illustrated in said embodiments of my invention is to synchronize the operation of said various embodiments of ignitions stems with the operation of the engine. Other synchronizing means that are actuated in synchronism with the operation of the engine, and which are adapted by the proper circuitry to said various embodiments, can be used instead of breaker points 19A and 19B. For example, the breakerless distributor described in US. Pat. No. 3,254,247 could be used instead of a distributor having the breaker points 19A and 193.

In FIGS. 4, 5, 6 and 8, numeral 36 refers to a condenser. Numerals 37 and 38 refer to inductance. Numeral 39 in FIGS. 6, 7 and 8 generally refers to an ignition coil or transformer of a new design or principle embodying my invention and will be more fully described in the description of operation of FIGS. 6, 7 and 8.

FEATURES COMMON TO THE OPERATION OF FIGS. 1, 3, 4, 5, 6, 7, 8, 9, l0, l1, 12 AND 13 The following descriptions of operation of the various circuits embodying my invention will consist of describing the operation for one closing and one opening of contacts 19A and 19B, although it is to be understood that the same cycle is continually taking place as long as the engine shaft is being rotated. It is also to be understood that the direction of current flow is taken to be in the direction from a negative potential to a less negative potential. As expressed herein and as understood by me, the direction of the flow of electrons is the same as the direction of the flow of current in a circuit. It is understood that there are different theories on this matter, but I elect to describe the direction of flow of current as being the same as the direction of the flow of electrons. In any event, my system operates the same regardless of which of these theories is chosen. It is also to be understood that in all the figures, like numbered elements are the same elements performing the same function in all the drawings, even though they may be connected to different places in the circuits of the various which i turn causes breaker contacts 19A and 19B tobe 7 opened and closed, and that the engine is also causing to be rotated the rotor contact 32 of distributor cap 34.-

DESCRIPTION OF FIG. 1

Beginning at the instant of time when breaker contacts 19A and 198 have just closed, a relatively small current will flow out of battery 11, through contacts 19A and 198, through resistor 18, through winding 15, and then through switch 12 and back to the battery 11. The magnetic sense of winding 16 is such that the flowing of this current through winding will cause an induced current to flow out the bottom terminal of winding 16, into base electrode 13B, out emitter electrode 13B, and back into the upper terminal of winding 16. The variation of this current with time will be substantially as illustrated graphically in FIG. 2A where the vertical axis represents current or i and the horizontal axis represents time or t.

The flowing of said current in the base to emitter path of transistor 13 causes transistor 13 to be substantially conductive between collector electrode 13C and emitter electrode 13E, thus allowing a relatively larger current, also substantially of the same shape in regard to time ,as illustrated in FIG. 2A, to flow from the negative terminal of battery 11 into ground, from ground through the collector electrode 13C to emitter electrode 13E path of transistor 13, through winding 22, through switch 12 and then back into the positive terminal of battery 11. The flow of this current in winding 22 and the magnetic sense of winding 23 causes a relatively smaller induced current to flow upward in winding 23 and out its top terminal, through diode 24, into the upper terminal of storage condenser 26, out the bottom of storage condenser 26 and then back into the bottom terminal of winding 23. In other words, the diode 24 is poled to permit the current to flow as described. This last mentioned current flow in winding 23, although smaller, is substantially proportional to the larger current flow in winding 22 and thus also varies with time substantially as illustrated in FIG. 2A, and said current charges siorage condenser 26 with electrical energy making its top terminal negative.

The values of the components of magnetic control device 14 and resistor 18 are chosen so that the current flowing in the base electrode 13B to emitter electrode 13E path of transistor 13 decreases to zero value preferably at substantially the same time or at a time approaching the time that the current charging storage condenser 26 decreases to zero value, or to some other predetermined value. The collector electrode 13C to emitter electrode 13E of transistorv 13 is thereby caused to become substantially nonconductive at substantially the same time that the current charging storage condenser 26 decreases to zero or to said predetermined value and thus cuts off the current flowing in winding 22 substantially at these same points in time. Thus the amount of time that the current flows in winding 22 depends on the values of the appropriate components of FIG. 1 and does not depend on the amount of time that contacts 19A and 19B are closed which time is inversely proportional to the rotative speed of the engine. The action described in this paragraph results in less energy being drawn from the battery at the lower rotative speeds of the engine and is especially a good feature when the engine is being started because at this time the starter motor places a heavy load upon the battery.

The induced current flowing in winding 23 and which charges storage condenser 26 is caused to flow by an induced voltage in winding 23 that is itself caused to be induced by the magnetic field being built up by the flow of current in winding 22, and which said induced voltage causes to be transferred the energy stored up in storage condenser 26 directly from battery 1 1 energy. In other words, the current flowing in winding 22 causes a magnetic field to be built up in the core of transformer 21 and the building up of this magnetic field induces a voltage in winding 23 which causes the above described charging of condenser 26 with energy directly from the battery 11. This is believed to be a unique way of charging a condenser and is in contrast to other ignition systems of the condenser discharge type which charge a condenser from a direct current source of energy or a battery's energy but through various intervening processes and not directly.

During the time that current is flowing in primary winding 22 a magnetic field, possessing a relatively small amount of energy, is built up in transformer 21 and when the current in primary winding 22 is cut off this magnetic field and its energy remains in transformer 21. While this magnetic field and its energy cannot be avoided, it is incidental to the operation of my invention and said magnetic field and its energy must be substantially disposed of in order to keep from harming transistor 13 and in order that the magnetic field of transformer 21 be as small as possible when transistor 13 becomes conductive again. Diode 25 and resistor 27 are connected across winding 23 for the purpose of dissipating the energy of the last mentioned magnetic field. When the collector electrode 13C to emitter electrode 131?. path of transistor 13 becomes substantially non-conductive, a relatively small current will flow downward in winding 23 out its bottom terminal, through resistor 27, through diode 25, and then back into the top terminal of winding 23. The flowing of this current will dissipate the energy of the magnetic field, mentioned in this paragraph, in the resistance of the last mentioned circuit.

Beginning at the time when breaker contacts 19A and 198 open, the current flowing in winding 15 is cut 011" and this induces a voltage in winding 17. The magnetic sense of winding 17 is such that this last mentioned induced voltage causes a current to flow out of the upper terminal of winding 17 into cathode electrode 28C, out gate electrode 28G, and then back into the bottom terminal of winding 17. This flow of current in the control circuit of silicon controlled rectifier 28 causes said silicon controlled rectifier to be conductive between its cathode electrode 28C and its anode electrode 28A and a large current will flow out of the negative upper terminal of storage condenser 26 into cathode electrode 28C, out of anode electrode 28A through winding 30 into ground, and out of ground into the lower plate of storage condenser 26. The flow of this current substantially discharges storage condenser 26. As a result of this last mentioned current flow in winding 30, a large voltage is induced in secondary winding 31, which is applied to a spark plug 35 by way or rotor contact 32 and one of the contacts 33 carried by distributor cap 34 which fires spark plug 35.

In the above description of operation of FIG. 1, I have described the circuit for one cycle of operation; that is, for one closing and one opening of contacts 19A and 19B although it is to be understood that the same cycle is repeated over and over.

DESCRIPTION OF FIG. 3

FIG. 3 is a modification of the circuit of FIG. 1. In accordance with this modification, an inductance 38 is connected between the lower terminal of winding 22 and emitter electrode 13E and also the series combination of diode 25 and resistor 27 is connected across the series combination of inductance 38 and winding 22 as shown in FIG. 3.

Beginning at the time when contacts 19A and 19B have just closed, transistor 13 will become conductive between collector electrode 13C and emitter electrode 13E as in the circuit of FIG. 1 and a current will flow out of the negative terminal of battery 11 into ground, from ground into collector electrode 13C, out emitter electrode 135, through inductance 38, through winding 22, and then through switch 12 and back to the upper positive terminal of battery 11. This current in inductance 38 and winding 22 substantially varies with time as illustrated in FIG. 28, starting from a zero value and increasing to a maximum value and decreasing to a minimum value.

Transformer 14 is so designed that along with the proper value of resistor 18, the current flowing in the base electrode 138 to emitter electrode 13E path of transistor 13 decreases to zero substantially at the same time that the current in inductance 38 and winding 22 decreases to a minimum value and causes transistor 13 to become non-conductive between its collector electrode 13C and emitter electrode 13E, cutting off the current in inductance 38 and winding 22. During the flow of current in inductance 38 and winding 22, the storage condenser 26 is charged in a manner similar to that described for the operation of FIG. 1 with the following exception.

In the circuit of FIG. 3, energy is transferred from battery 11 into storage condenser 26 by the combination of two processes. One, energy is transferred directly from battery 11 through transformer 21 into condenser 26 as in the circuit of FIG. 1, and two, energy from battery 11 is first momentarily stored in inductance 38 and then inductance 38 releases this energy which is transferred into condenser 26 by transformer 21.

At the time when the current in inductance 38 and winding 22 is cut off, there will be a magnetic field in each of these elements possessing relatively small amounts of energy and a current will flow upward in inductance 38, through winding 22, through diode 25, through resistor 27 and back into the lower terminal of inductance 38 and said flow of current through the resistance of said circuit will dissipate both the said magnetic energies in the form of heat. In short, the magnetic energies in inductance 38 and in winding 22 are dissipated in the form of heat.

The parts of the circuit of FIG. 3 not described here operate and function in the same manner as described for FIG. 1. The presence of inductance 38 in the circuit of FIG. 3 increases the voltage with which condenser 26 is charged, with a given turn ratio of windings of transformer 21.

Inductance 38 limits the maximum value of the current flowing in primary winding 22 when the output circuit of transistor 13 is conductive. Since the current flowing in secondary winding 23 is substantially proportional to the current flowing in primary winding 22 during this same time, inductance 38 also limits the maximum value of the secondary current which also varies substantially as illustrated by FIG. 2B. Thus, it is not necessary to limit the maximum value of these same two currents by electrical resistance but'it is in fact desirable to keep the value of the electrical resistance of the circuits, in which these same two currents flow, as small as possible. The smaller the losses in the magnetic core of transformer 21 and the smaller the electrical resistances, just mentioned, the greater the voltage to which the storage capacitor 26 is charged. I

DESCRIPTION OF FIG. 4

FIG. 4 is a modification of FIG. 1 and in accordance with this modification a condenser 36 and an inductance 37 as connected in series across the series combination of condenser 26 and silicon controlled rectifier 28. Low voltage winding 30 is connected across condenser 36.

The manner in which this modification operates is as follows: With condenser 26 charged and beginning at a time when contacts 19A and 198 have just opened, and thus silicon controlled rectifier 28 has just become conductive between its cathode electrode 28C and its anode electrode 28A, a relatively large current will flow out of the negative upper terminal of condenser 26, through the cathode electrode 28C to anode electrode 28A path of silicon controlled rectifier 28, through inductance 27, into the upper terminal of condenser 36 making it negative, out the lower terminal of condenser 26 into ground, from ground back into the lower terminal of condenser 26.

As a result of this current flow, condenser 26 is substantially discharged and condenser 36 is charged, and a voltage will rise rapidly across condenser 36 with the proper value of inductance 37. Since winding 30 is across or in parallel with condenser 36, the same voltage will rise rapidly across winding 30 and this in turn causes aproportionally much larger induced voltage to rise rapidly across winding 31. The voltage across winding 31 is applied to a spark plug 35 by-way of rotor contact 32 and one of the contacts 33 carried by distributor cap 34. When the voltage across winding 31 rises to a certain value, the spark plug 35 fires and condenser 36 is discharged.

The presence of inductance 37 in the circuit ofFIG. 4 limits the size of the discharge current of condenser 26 and prevents silicon controlled rectifier 28 from being destroyed by any physical shorts in transformer 29 or by any grounds in the secondary circuit of transformer 29.

DESCRIPTION OF FIG. 5

The circuit of FIg. 5 is modified from the circuit of FIG. 1 by the inclusion of inductance 37 and condenser 36 and these elements affect the circuit of FIG. 5 in the same manner that they affected the circuit of FIG. 4. The circuit of Flg. 5 is also modified from the circuit of FIG. 1 by the inclusion of energy inductance 38 and the series connected combination of diode 25 and energy dissipating resistor 27 as shown in FIG 5 and these elements affect the circuit of FIG. 5 in the same manner as they affected the circuit of FIG. 3.

DESCRIPTION OF FIG. 6

The circuit of FIG. 6 is particularly modified from the circuit of FIG. 1 in the following respect. In FIG. 6 a unique and novel ignition coil or transformer embodying a feature of a form of my invention and generally designated by reference numeral 39 takes the place of an performs the functions of both the transformer 21 and the standard ignition coil 29 of FIG. 1.

Transformer 39 consists of two main windings on a common magnetic core, a primary winding 40 and a secondary winding that is tapped at two points to form three different functional secondary windings 41, 42 and 43.

It is to be understood that as connected in FIG. 6, all four windings 40, 41, 42 and 43 have the same magnetic sense, that is, if an induced voltage in one winding, caused by a change in the magnetic field of transformer 39, tends to cause a current to flow in that winding in a certain direction, either in an upward or downward direction when viewing FIG. 6, then there will be induced voltages in the remaining three windings tending to cause a current to flow in each in the same direction.

In the circuit of FIG. 6, winding 40 performs the same function that winding 22 does in FIG. 1; winding 41 of FIG. 6 performs the same function that winding 23 performs in FIG. 1; and the additive combination of windings 41 and 43 of FIG. 4 performs the same function that winding 31 performs in FIG. 1. Also winding 42 of FIG. 6 performs the same function that winding 30 performs in FIG. 1 plus an additional function of disposing of the energy of the magnetic field of transformer 39, as will be explained below.

Beginning at an instant when contacts 19A and 198 have just closed, transistor 13 will be caused to become conductive by magnetic control device 14 in the same manner as was described for FIG. 1. A current from battery 11 will then flow in winding 40 in the same manner that a current flowed in winding 22 of FIG. 1.

The flowing of said current in winding 40 will cause an induced current to flow in winding 41 for the same reason and in a similar manner as was described for the current flow in winding 23 of FIG. 1. The induced current in winding 41 will flow downward and out its lower terminal into ground, from ground into the lower terminal of condenser 26, out the upper terminal of condenser 26, and through diode 24 and back into the upper terminal of winding 41. The flow of this current results in condenser 26 being charged and the lower terminal of condenser 26 to become negative.

When transistor 13 becomes substantially non-conductive, in the same manner as was described for FIG. 1, there will be a magnetic field in transformer 39 just as there was in transformer 21 of FIG. 1, and the energy of this magnetic field must be disposed of as was done in connection with FIG. 1. Thus when transistor 13 becomes substantially non-conductive, an induced current will flow upward in the winding 42 and out the upper terminal of winding 42 into ground, from ground intothe lower terminal of condenser 36, out the upper terminal of condenser 36 and back into the lower terminal of winding 42. The flow of this current will dispose of the energy of the magnetic field of transformer 39 by storing some energy in condenser 36 and which will make the lower terminal of condenser 36 negative. The energy stored in condenser 36 is minor and the main purpose of this last mentioned action being to dispose of the energy of the magnetic field of transfonner 39 that exists. in transformer 39 at the time that transistor 13 becomes substantially nonconductive.

When contacts 19A and 198 open, silicon controlled rectifier 28 becomes conductive in the same manner that it did in FIG. 1 and a large limited current flows out of the negative lower terminal of condenser 26 into ground, from ground into the lower terminal of condenser 36, out of the upper terminal of condenser 36 and through inductance 37, then into cathode electrode 28C of silicon controlled rectifier 28, then out of anode electrode 28A and back into the upper terminal of condenser 26. The flow of this current charges condenser 36, making its lower terminal negative, and the voltage on condenser 36 will rise very rapidly with the proper value of inductance 37. Since winding 42 is connected across condenser 36, there will be the same voltage rise on winding 42 and this will cause a proportionally greater induced voltage rise across the series combination of windings 41 and 42. The direction of this latter induced voltage risewill be upward in both windings 41 and 43 and will be applied across the spark gap of spark plug 35: by way of rotor contact 32 and one of the contacts 33 carried by distributor cap 34. When the voltage rise on the series combination of windings 41 and 43 reaches a certain value, the spark plug 35 fires and condenser 36 is discharged.

DESCRIPTION OF FIG. 7

The circuit of FIG. 7 is a modification of FIG. 6. In FIG. 7 inductance 37 and condenser 36 have been excluded. In FIG. 7 when silicon controlled rectifier 28 becomes conductive, the voltage on condenser 26 is applied across winding 42 and this causes transformer 39 to fire spark plug 35 in the same manner that the voltage of condenser 36 of FIG. 6 across winding 42 caused spark plug 35 to fire in the circuit of FIG. 6.

FIG. 7 is also modified from FIG. 6 by the inclusion of diode 25 and resistor 27 and these two elements have the same effeet in the circuit that they had in the circuit of FIG. 3, as will be readily apparent to those skilled in the art.

FIG. 7 is also modified from the circuit of FIG. 6 by the inclusion of inductance 38 which is connected between the lower terminal of winding 40 and emitter electrode 13E. Inductance 38 has the same effect on the circuit of FIG. 7 that it had on the circuit of FIG. 3. Inductance 38 also has an effect on the circuit of FIG. 7 that it doesnot have in the circuit of FIG 3, specifically the following effect. When silicon controlled rectifier 28 becomes conductive in the circuit of FIG. 7, the voltage of condenser 26 is applied across winding 42 which causes an induced voltage in winding 40 and inductance 38 effectively prevents this induced voltage in winding .40 from being applied across the collector electrode 13C to emitter electrode 13E of transistor 13 and prevents transistor 13 from being destroyed if this induced voltage in winding 40 is too large a value for transistor 13.

DESCRIPTION OF FIG. 8

FIG. 8 is modified from the circuit of FIG. 6 by the inclusion of diode 25, resistor 27 and inductance 38. These elements are connected as shown in FIG. 8 and they have the same effect on the circuit of FIG. 8 that they have on the circuit of FIG. 7.

DESCRIPTION OF no. 9

The circuit of FIG. 9 is modified from the circuit of FIG. 3 and differs in the following respects: Numeral 47 designates a capacitor which is connected between collector electrode 13C and emitter electrode 135. Numeral 48 generally designates a magnetic control device having a primary winding and a secondary winding wound on a common magnetic core. Numeral 49 designates said primary winding and numeral 50 designates said secondary winding. Numeral 51 designates a semi-conductor diode which is connected across primary winding 49. Inductance 52 is connected with one end of secondary winding 23. The other end of secondary winding 23 is connected to base electrode 138. Other differences between FIG. 9 and FIG. 3 may be noted by referring to the drawings and the following description.

Assuming for the present that ignition switch 12 is closed, that current is flowing in primary winding 49, that a magnetic field exists in the core of magnetic control device 48, and that storage capacitor 26 has a negative charge on its lower plate or temtinal which is connected to ground, the operation of FIG. 9 is as follows:

Beginning at a time when breaker contacts 19A and 198 just open, the current flowing in primary winding 49 is cut off and causes the magnetic field. in the magnetic core of magnetic control device to collapse and induce a voltage in secondary winding 50. The magnetic sense of secondary winding 50 is such that the induced voltage causes a current to flow in the input circuit of silicon controlled rectifier 28 which causes the output circuit of silicon controlled rectifier 28 to be conductive. When the output circuit of silicon controlled rectifier 28 thus becomes conductive, a relatively large current flows out of the negative lower or grounded plate or terminal of storage capacitor 26, through low voltage winding 30, through the output circuit of silicon controlled rectifier 28, and back into the upper or non-grounded plate or terminal of storage capacitor 26. As a result of this current flow in low voltage winding 30 a relatively large voltage is induced in high voltage winding 31 which is applied to spark plug 35 by way of rotor 32 and one of the contacts 33 carried by distributor cap 34 which fires spark plug 35. All the energy of storage capacitor 26 is not used during the flow of this last mentioned current and when this current has ceased, storage capacitor 26 will be left with a reverse or negative charge on its upper, or nongrounded plate or terminal. The presence of this negative charge on the upper or non-grounded plate or terminal of storage capacitor 26 will cause the output circuit of silicon controlled rectifier 28 to become non-conductive and the out- 'put circuit will remain non-conductive until the next opening of breaker contacts 19A and 19B.

After the firing of spark plug 35 the negative charge or voltage on capacitor 26 and the voltage of battery 11 will aid each other to cause a relatively small current to flow, out of the negative upper plate or terminal of storage capacitor 26, through semi-conductor v diode 24, through inductance 52, through secondary winding 23, through the input circuit of transistor 13, through ignition switch 12, through battery 11, and back into the lower plate or temtinal of storage capacitor 26. For purpose of explanation this circuit, just described, I will refer to as "the charging circuit". This small current flow ing in the input circuit of transistor 13 causes the output circuit of transistor 13 to be conductive and then battery 11 causes a relatively larger current to flow out of its negative terminal, through primary winding 22, through the conductive output circuit of transistor 13, through ignition switch 12, and back into its positive terminal. The flow of this current in primary winding 22 will energize transformer 21 and cause a voltage to be induced in secondary winding 23. The magnetic sense of secondary winding 23 is such that the voltage induced in it causes the upper end of secondary winding 23 to be negative in respect to its lower end. The induced voltage in secondary winding 23, thus having the proper polarity, causes the current flowing in the charging circuit to continue to flow until storage capacitor 26 is fully charged, with its lower plate or terminal then being negative. During the time this current is flowing in the charging circuit to charge storage capacitor 26 it maintains the output circuit of transistor 13 conductive because it flows through the input circuit of transistor 13. Since the output circuit of transistor 13 is conductive during the charging of storage capacitor 26 current flows in primary winding 22 during this same period of time and energizes transformer 21 which energizes the charging circuit to charge the capacitor 26.

The small current flowing in the charging circuit which includes inductance 52 and the larger current flowing in primary winding 22 are pulses of current, both currents varying with respect to time, substantially as illustrated by FIG. 2B.

When the pulse of current flowing in inductance 52 is increasing to a maximum value, energy is being stored in the magnetic field of inductance 52 and when this current is decreasing to a minimum value, the magnetic field of inductance 52 releases its energy into storage capacitor 26. Inductance 52 limits the maximum value of the currents flowing in the circuits and components involved in the charging of storage capacitor 26. It is desirable to make the electrical resistances, of the circuits and components which are involved in charging storage capacitor 26, as small as possible. Inductance 52 causes storage capacitor 26 to be charged to a voltage greater than possible by transformer 21 acting along. The smaller the losses in the magnetic core of transformer 21 and the smaller the electrical resistances of the circuits and components which are involved in charging storage capacitor 26, the greater the voltage with which the storage capacitor 26 will be charged.

During the period of time the output circuit of transistor 13 is conductive and current is flowing in primary winding 22, a magnetic field is built up in the magnetic core of transformer 21. When the output circuit of transistor 13 becomes non-conductive and, cuts off the current in primary winding 22, the magnetic field existing in transformer 21 collapses and causes an induced current to flow out of the upper end of primary winding 22, into and out of capacitor 47, through ignition switch 12, through battery 11, and back into the lower end of primary winding 22. This induced current flows back and forth in this last mentioned circuit until the energy that existed in the magnetic field of transformer 21 has been dissipated in the form of heat partly by reason of the electrical resistance of the circuit in which the induced current flows, and partly by reason of the hysteresis loss in the magnetic core of transformer 21.

When breaker contacts 19A and 19B close, a current flows out of the negative terminal of battery 11, through closed breaker contacts 19A and 19B, through resistor 18, through primary winding 49, through ignition switch 12, and back into the upper positive terminal of battery 11. The flowing of this current in primary winding 49 builds a magnetic field up in the magnetic core of magnetic control device 48. The function of resistor 18 is to limit the value of current flowing in primary winding 49 to a desired value. The function of semi-conductor diode 51 is to limit the negative induced voltage on gate electrode 286 when breaker contacts 19A and 19B close. The circuit of FIG. 9 is then in condition for the next opening of breaker contacts 19A and 198. The sequence of the above described operation is consecutively repeated for each following opening and closing of contacts 19A and 198.

It may be noted that if storage capacitor 26 happens to be uncharged when the ignition switch 12 is closed then battery 11 will cause a current to flow in the charging circuit and this will trigger the output circuit of transistor 13 into a conductive state or condition. When the said output circuit of transistor 13 is thus in a conductive state or condition, the capacitor 26 is charged in the manner previously described.

DESCRIPTION or FIG. 10

The circuit of FIG. 10 is a modification of FIGS. 3 and 9 and differs from FIGS. 3 and 9 in the following respects. Numeral 44 designates a semi-conductor diode. Numeral 45 designates a capacitor. Numeral 46 designates a semi-conductor diode. Numeral 45 designates a capacitor. Numeral 46 designates a resistor. In the drawing of FIG. 10, a pictorial top plan view of a specially built transformer, designated generally by the numeral 21A, is shown for the purpose of better explanation of this modification. Other differences may be noted by referring to the drawings.

As shown in FIG. 10, the magnetic core of transformer 21A is the shell type core, the axial length of the windows is about three times greater than the heights of the windows. Numeral 22A designates the primary or low voltage winding. Numeral 23A designates the secondary or high voltage winding. The two windings, primary winding 22A and secondary winding 23A, are wound concentrically about the center leg of the magnetic core. The two windings are disposed side-by-side on the center leg of the magnetic core, as shown in the drawing. The two windings preferably occupy equal areas of each window area so that the heat losses of the two windings may be as nearly equalized as possible. Together the two windings preferably occupy as much of the areas of the windows as practically possible so that each winding has as small a resistance as practically possible. The ratio of resistance to leakage inductance is here considered to be the numerical value that equals the numerical value of the resistance in ohms divided by the numerical value of the leakage inductance in henries. When wound in the manner described above and disposed on the center leg side-by-side, each of primary winding 22A and secondary winding 23A has a considerably smaller ratio of resistance to leakage inductance than when one of the primary and secondary windings is wound superimposed over the other winding of said windings as is customary in a two-winding small conventional power transformer. Transformer 21A is wound to provide a low ratio of resistance to leakage inductance for the purpose of the circuit of FIG. 10.

In my special transformer, the leakage inductance of a winding relative to the resistance of the same winding is several times greater, on the order of about ten times greater for example, than is the leakage inductance of a similar winding relative to the same amount of resistance in the corresponding winding of comparable conventional transformers. This is obtained by the construction and arrangement of the core and the windings in the windows of the core as above described.

In the ratio of R/L, wherein R is the resistance in a winding and L" is the inductance in the same winding, my special transformer as above described has a relatively large, say on the order of ten times as much, leakage inductance, assuming the same amount of resistance in the corresponding winding of a comparable conventional transformer.

The ratio of R/L influences the degree of the voltage with which capacitor 26 is charged. The smaller the ratio, that is the larger the leakage inductance is to the resistance of the same winding, the greater the voltage with which the capacitor is charged.

More detailed information on how to obtain leakage inductance, sufficient for the purposes of FIG. 10, may be had by referring to the first edition of a book entitled Small:

Transformers and Inductors" by I(.A. MacFayden and published in 1953 by Chapman and Hall, 37 Essex Street, WC. 2, London, Eng.

Assuming that ignition switch 12 is closed, that the engine is running and causing breaker contacts 19A and 198 to be repeatedly opened and closed, and that storage capacitor 26 has a negative charge on its right hand plate or terminal, the operation of FIG. 10 is as follows.

Beginning at a time when breaker contacts 19A and 198 have just opened, a small current will flow, out of the negative terminal of battery. 11 into ground, from ground through the input circuit of silicon controlled rectifier 28, through semiconductor diode 44, into and out of capacitor 45, through resistor 18, through ignition switch 12, and back into the positive terminal of battery 11. This small current flowing in the input circuit of silicon controlled rectifier 28 causes the output circuit of silicon controlled rectifier 28 to become conductive. When the output circuit of silicon controlled rectifier 28 thus becomes conductive, a relatively large current flows out of the negative right hand plate or terminal of storage capacitor 26, through low voltage winding 30, through the output circuit of silicon controlled rectifier 28, and back into the left hand plate or terminal of storage capacitor 26. As a result of this current flow in low voltage winding 30, a relatively large voltage is induced in high voltage winding 31 which is applied to spark plug 35 by way of rotor 32 and one of the contacts carried by distributor cap 34 which fires spark plug 35. All of the energy of storage capacitor 26 is not used during the flow of this last mentioned current and when it has ceased flowing, storage capacitor 26 will be left with a reverse or negative charge on its left hand plate or terminal. The presence of this negative charge or voltage on the left hand plate or terminal of storage capacitor-26 causes the output circuit of silicon controlled rectifier 28 to become nonconductive and the output circuit of silicon controlled rectifier 28 remains nonconductive until the next opening of breaker contacts 19A and 198.

After the firing of spark plug 35 the negative voltage on the left hand plate or terminal of storage capacitor 26 and the voltage of battery 11 will aid each other to cause a relatively small current to flow out of the negative left hand plate or terminal of storage capacitor 26, through semiconductor diode 24, through secondary winding 23A, through the input circuit of transistor 13, through primary winding 22A, through ignition switch 12, into battery 11, out of battery 11 and into ground, from ground through low voltage winding 30, and back into the right hand plate or terminal of storage capacitor 26. For purposes of explanation, I will refer to this circuit, just described, as the charging circuit". The small current flowing in the input circuit of transistor 13 causes the output circuit of transistor 13 to be conductive. When the output circuit of transistor 13 thus becomes conductive, battery 11 causes a relatively larger current to flow out of its negative terminal, through the conductive output circuit of transistor 13, through primary winding 22A, through ignition switch 12, and back into the positive terminal of battery 11. The flow of this current in primary winding 22A energizes transformer 21A and causes a voltage to be induced in secondary winding 23A. The magnetic sense of secondary winding 23A is such that, the voltage induced in it causes the lower end of secondary winding 23A to be negative in respect to its upper end. The induced voltage in secondary winding 23A, thus having the proper polarity, causes the current flowing in the charging circuit to continue to flow until storage capacitor 26 is fully charged, with its right hand plate then being negatively charged. During the time this current is flowing in the charging circuit to charge storage capacitor 26, the output circuit of transistor 13 is maintained conductive because the current flowing in the charging circuit flows in the input circuit of transistor 13. Since the output circuit of transistor 13 is conductive during the charging of storage capacitor 26, current flows in primary winding 22A during this same period of time and energizes transformer 21A which energizes the charging circuit to charge the storage capacitor 26.

The small current flowing-in the charging circuit which includes secondary winding 23A and the larger current flowing in primary winding 22A, during the period of time the output circuit of transistor 13 is conductive, are pulses of current. Both pulses of currents vary with respect to time substantially as illustrated by FIG. 2B.

Leakage inductance associated with a winding of a twowinding transformer is considered, for purposes of analysis, as being caused by a leakage magnetic field that exists when current flows in the winding and this leakage magnetic field is further considered as linking only that winding producing it and not the other winding of the transfonner.

During the period of time, substantially illustrated by FIG. 28, that the currents flowing in primary winding 22A and secondary winding 23A are increasing toward a maximum value energy is being stored in the leakage magnetic fields associated with these windings. During the period of time that said currents are decreasing to a minimum value, said leakage magnetic fields are releasing said. stored energy and said released energy is being caused to be transferred into storage capacitor 26.

The leakage inductances designed and built into transformer 21A limits the maximum value of the current flowing in primary winding 22A and hence limits the current flowing in the output circuit of transistor 13 and also limits the maximum value of the current flowing in the charging circuit. It is desirable to make the electrical resistance, of the two circuits and components involved in charging storage capacitor 26, as small as possible. Storage capacitor 26 is charged with a voltage substantially greater than the voltage of battery 11 as multiplied by the turn ratio of the transformer 21A by reason of the inclusion of the described leakage inductances in the transformer 21A. The smaller the losses in the magnetic core of transformer 21A and the smaller the electrical resistances of the two circuits and components which are involved in charging storage capacitor 26, the greater the voltage with which the storage capacitor 26 will be charged.

It is well known that the input and output circuits of a transistor can conduct but a limited amount of current, and that subjecting either of these circuits to too much current can burn out, destroy and render inoperative said circuits. I protect the transistor 13 of my circuits against such destruction by reason of an over-supply of current by limiting the current supplied thereto by inductance, which in FIG. 3 is the inductance 38, in FIG. 9 is inductance 52, and, in FIG. 10 is the leakage inductance designed and built into the transformer 21A.

During the period of time the output circuit of transistor 13 is conductive, a magnetic field is built up in the magnetic core of transformer 21A. When the output circuit of transistor 13 becomes nonconductive, an induced current flows out of the upper end of primary winding 22A, through ignition switch 12, through battery 11, into and out of capacitor 47, and back into the lower end of primary winding 22A. This induced current flows back and forth in the last mentioned circuit until the energy that existed in the magnetic field of transformer 21A has been dissipated in the form of heat, partly by reason of the electrical resistance of the circuit and partly by reason of the hysteresis loss in the magnetic core of transformer 21A. The said dissipation of the said energy prevents harm to transistor 13 and reduces the magnetic field in the core of transformer 21A.

During the time breaker contacts 19A and 19B are open, the current that flows in the input circuit of silicon control rectifier, previously described, charges the upper plate of capacitor 45 with a negative charge or voltage. When contacts 19A and 19B close, capacitor 45 discharges through resistor 46. Semi-conductor diode 44 prevents the negative voltage on capacitor 45 from being applied to gate electrode 286 while capacitor 45 is being discharged. The value of resistance of resistor 46 is made great enough so that it has negligible influence on the input circuit of silicon controlled rectifier when breaker contacts 19A and 19B are open. Resistor 18 limits the current flowing in the input circuit of silicon controlled rectifier 28 when breaker contacts 19A and 19B are open, and limits the current flowing through breaker contacts 19A and 19B when they are closed.

It may be noted that if storage capacitor 26 happens to be uncharged when the ignition switch 12 is closed, then battery 11 will cause a current to flow in the charging circuit and this will trigger the output circuit of transistor 13 into a conductive state or condition. When the said output circuit of transistor 13 is thus in a conductive state or condition, the storage capacitor 26 is charged in the manner previously described.

In the description and claims, in referring to my transistor and my silicon controlled rectifier, I have used the terms input circuit and output circuit". In my transistor 13, for example, the input circuit is the path for the current to flow in the transistor between base 133 and emitter 13E, and the output circuit" is the path for the current to flow in the transistor between collector 13C and emitter 13E. In my silicon controlled rectifier 28, for example, the input circuit" is the path for the current to flow in the rectifier between cathode 28C and gate 286, and the output circuit is the path for the current to flow in the rectifier between cathode 28C and anode 28A.

DESCRIPTION OF FIG. 1

The circuit of FIG. 11 is a modification of FIGS. 3,9 and and differs from these circuits in the following respects: In FIG. 11 a resistor 53 is connected across capacitor 26. Numeral 54 designates an inductance having a magnetic core connected in series with a semi-conductor diode, designated by numeral 55, and this combination in series is connected, as shown in FIG. 11, across capacitor 26. Numeral 56 designates a semi-conductor diode and is connected, as shown, across the input circuit 133 to 13E of transistor 13. The transformer 21A of FIG. 11 is the same in structure and function as the transformer 21A of FIG. 10. Other differences between FIG. 11 and FIGS. 3,9 and 10 may be noted by referring to the drawings and the following description.

Breaker contacts 19A and 19B, resistor 18, magnetic control device 48, and diode 51 function in a manner similar to that described for these said elements in the description of FIG. 9, to cause the output circuit of silicon controlled rectifier 28,to be conductive upon the opening of contacts 19A and 19B.

Assuming for the present that ignition switch 12 is closed, that breaker contacts 19A and 19B are closed, and that capacitor 26 has a negative charge possessing energy on its right hand plate or terminal that is connected to cathode electrode 28C, the operation of FIG. 11 is as follows.

Diode 55 prevents said charge from discharging through inductance 54 and diode 24 prevents said charge from discharging through secondary winding 23A. Resistor 53 will leak off some of said charge, but the resistor 53 is selected to have such a large value of resistance that the operation of FIG. 11 will be affected by such leakage to only a small degree. The sole function of resistor 53 is to discharge capacitor 26 when ignition switch 12 is open.

Now beginning at a time when contacts 19A and 19B have just opened and the output circuit 28C to 28A of silicon controlled rectifier 28 has become conductive, a current will flow out of the right hand plate or terminal of capacitor 26 and through the output circuit 28C to 28A, through primary winding 30, through ground, through battery 11, through ignition switch 12, through semi-conductor diode 56 and into the left hand plate or terminal of capacitor 26. The flow of this current in primary winding 30 will fire spark plug 35 in the same manner as described in the description of FIG. 9. For purposes of explanation and claiming this circuit just described may be referred to as the capacitor discharge circuit. All the energy of capacitor 26 is not used during the flow of this last mentioned current and when this current has ceased, capacitor 26 will be left with a reverse or negative charge on its left hand plate or terminal that is connected to base electrode 13B. The presence of this negative charge on the left hand plate or terminal of capacitor 26 causes the output circuit of silicon controlled rectifier 28 to become non-conductive and said output circuit will remain non-conductive until the next opening of breaker contacts 19A and 19B.

After the firing of spark plug 35 the reverse or negative charge on the left hand plate or terminal of capacitor 26 and the voltage of battery 1 1 will aid each other to cause a current to flow, out of the negative left hand plate or terminal of capacitor 26, through the input circuit of transistor 13, through ignition switch 12, through battery 11, through ground, through secondary winding 23 A,. through semiconductor diode 24, and into the right hand plate or terminal of capacitor 26. For purposes of explanation and claiming this circuit just described may be referred to as the charging circuit. This current flowing in the input circuit of transistor 13 causes the output circuit of transistor 13 to be conductive and then battery 11 causes a relatively larger current to flow out of its negative terminal, through ground, through primary winding 22A, through the output circuit of transistor 13, through ignition switch 12, and back into the positive terminal of battery 11. The flow of this current in primary winding 22A will energize transformer 21A and cause a voltage to be induced in secondary winding 23A. Flux that is common to all the windings on a transformer is sometimes referred to as mutual magnetic flux, and it is this mutual magnetic flux that produces said voltage in secondary winding 23A. Secondary winding 23A is wound to have such a magnetic sense that the said induced voltage causes its upper end to be negative in respect to its lower or grounded end. This said induced voltage in secondary winding 23A, thus having the proper polarity, causes the current flowing in the charging circuit to continue to flow until capacitor 26 is again fully charged, with its right hand plate or terminal being negative (which is the correct polarity for firing spark plug 35). During the time this current is flowing in the charging circuit to charge capacitor 26 it maintains the output circuit of transistor 13 conductive because it flows through the input circuit 133 to 13E of transistor 13. Shoe the output circuit of transistor 13 is conductive during the charging of capacitor 26 current flows in primary winding 22A during this same period of time and energizes transformer 21A which energizes the charging circuit to change capacitor 26.

The current flowing in the charging circuit which includes secondary winding 23A and the larger current flowing in primary winding 22A, during the period of time the output circuit of transistor 13 is conductive, are pulses of current. Both pulses of current vary with respect to time substantially as illustrated by FIG. 28.

During the period of time, substantially illustrated by FIG. 28, that the currents flowing in primary winding 22A and secondary winding 23A are increasing toward a maximum value, energy is being stored in the leakage magnetic fields associated with these windings. During the period of time that said currents are decreasing to a minimum value, said leakage magnetic fields are releasing said stored energy and said released energy is being caused to be transferred into storage capacitor 26.

The leakage inductances designed and built into trans former 21A limits the maximum value of the current flowing in primary winding 22A and hence limits the current flowing in the output circuit of transistor 13 and also limits the maximum value of the current flowing in the charging circuit. It is desirable to make the electrical resistance, of the two circuits and components involved in charging storage capacitor 26, as small as possible. Storage capacitor 26 is charged with a voltage substantially greater than the voltage of battery 11 as multiplied by the turn ratio of the transformer 21A by reason of the inclusion of the described leakage inductances in the transformer 21A. The smaller the losses in the magnetic core of transformer 21A and the smaller the electrical resistances of the two circuits and components which are involved in charging capacitor 26, the greater the voltage with which the storage capacitor 26 will be charged.

It may be noted that when switch 12 is closed and capacitor 26 is uncharged that battery 11 will cause a current to flow in the said charging circuit and hence in the input circuit of transistor 13. As a result of this current flow in the input circuit of transistor 13 the output circuit of transistor 13 will become conductive. When the output circuit of transistor 13 is thus conductive, capacitor 26 is charged in the manner described above.

During the period of time that the output circuit of transistor 13 is conductive and current is flowing in primary winding 22A from battery 11 a magnetic field is built up in transformer 21A. When the output circuit of transistor 13 becomes non-conductive and cuts off said current in primary winding 22A, the magnetic field existing in transformer 21A collapses and causes an induced current to flow out of the upper end of primary winding 22A, that is connected to collector electrode 13C, through resistor 27, through ground, and into the lower end of primary winding 22A. The function of resistor 27 is to prevent harm to transistor 13 by completing a circuit for said induced current to flow in, and resistor 27 also dissipates the energy of the magnetic field existing in transformer 21A when the output circuit of transistor 13 becomes non-conductive. Resistor 27 is chosen to have a value of resistance low enough that the voltage developed across the substantially non-conductive output circuit of transistor 13 is not great enough to harm transistor 13.

After the firing of spark plug 35 the above said reverse or negative charge on the left hand plate or terminal of capacitor 26 causes a current to flow through inductance 54 and diode 55. As a result of this current flow a portion of said reverse charge is transferred to the right hand plate or terminal of capacitor 26 (which is the proper condition of capacitor 26 for firing spark plug 35). Thus the function of the combination of inductance 54 and diode 55 is to provide a partial recharging of capacitor 26. Another portion of said reverse charge is transferred to the right hand plate or terminal of capacitor 26 via the said charging circuit as described above. It is to be understood that the circuit of FIG. 11 will function without inductor 54 and diode 55. The advantages of including inductor 54 and diode 55 in the circuit of FIG. 11 are that smaller currents .will flow in the windings of transformer 21A and less current will flow in the. output circuit of transistor 13.

DESCRIPTION OF FIG. 12

FIG. 12 is a partial schematic circuit diagram and is a modification of FIG. 11. In FIG. 12 the combination of trans former 21 and inductance 38 is employed to perform the same function that transformer 21A performs in FIG. 11. Transformer 21 and inductance 38 are connected as shown. It is to be understood that transformer 21 is a conventional power transformer and that a conventional power transformer is one which is constructed to minimize the value of the leakage inductances associated with the windings. An example of a small conventional power transformer would be the power supply transformer of a home radio or television receiver. Transformer 21 and inductance 38 affect the circuit of FIG. 12 in a manner similar to the way they affect the circuit of FIG. 3. The operation of FIG. 12 is similar to the operation of FIG. 11.

DESCRIPTION OF FIG. 13

FIG. 13 is a partial schematic circuit diagram and is a modification of FIG. 11. In FIG. 13 the combination of transformer 21 and inductance 52 is employed to perform the same function that transformer 21A performs in FIG. 11. Transformer 21 and inductance 52 are connected as shown. Transformer 21 and inductance 52 affect the circuit of FIG. 13 in a manner similar to the way they affect the circuit of FIG. 9. The operation of FIG. 13 is similar to the operation of FIG. 1 l.

The present disclosure includes that contained in the appended claims, as well as that of the foregoing descriptionv Although this invention has been described in its preferred form with a certain degree of particularly, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. An ignition system for igniting the combustible mixture of an internal combustion engine and including a source of direct current and a spark discharge device and comprising in combination, a transformer having a primary winding and three secondary windings, namely a first secondary winding, a second secondary winding, and a third secondary winding, an electronic conductive device having current carrying output terminal means and having input temtinal means for controlling the conductivity of the path of current flow between said output terminal means, a first current path including the path between said output terminal means and said primary winding connected across the source of direct current to conduct a flow of current from the source of direct current through said primary winding, an asymmetrical conductive device poled to conduct a first induced current flow in said first secondary winding that opposes the building up of the magnetic field of said transformer during the time that current from said source of direct current is flowing in said primary winding, a first capacitor connected to be charged and discharged in synchronism with the operation of the engine, a second current path including said first secondary winding and said asymmetrical conductive device connected in seriesacross said first capacitor to charge said first capacitor by said first induced current, first control means connected to said input terminal means of said electronic conductive device to control the flow of current from said source of direct current in said primary winding in synchronism with the operation of the engine and to cause to be interrupted said latter current flow at substantially the same time or at a time approaching the same time that said first capacitor is charged, an electronic switch having current carrying output terminal means and input terminal means to control the conductivity of the path between said output terminal means, an inductance, a second capacitor, discharge means including the path between said output terminal means of said electronic switch, said inductance and said second capacitor connected in series across said first capacitor and said second capacitor also connected in parallel with said second secondary winding and including said third secondary winding connected with said spark discharge device to discharge said first capacitor through said inductance into said second capacitor thereby causing a voltage on said second capacitor and said second secondary winding which causes a second induced current to flow in said third secondary winding to produce a spark at said spark discharge device, and second control means connected to the said input terminal means of said electronic switch to control the conductivity of the path between said output terminal means in synchronism with the operation of the engine.

2. An ignition system as defined in claim 1 wherein said first control means and said second control means include in common a magnetic control device having a primary winding and two secondary windings, one secondary winding being included in said first control means and the other secondary winding being included in said second control means and said magnetic control device being energized by current from said source of direct current conducted through said primary winding of said magnetic control device in synchronism with the operation of the engine.

3. An ignition system as defined in claim 1 wherein said electronic conductive device is a transistor, said asymmetrical conductive device is a semi-conductor diode, and said electronic switch is a thyratron tube.

4. An ignition system as defined in claim 1 wherein said electronic conductive device is a transistor, said asymmetrical device. is a semi-conductor diode,'and said electronic switch is a silicon controlled rectifier.

5. An ignition system for igniting the combustible mixture of an internal combustion engine and including a source of direct current and a spark-discharge device and comprising in combination a transformer having a primary winding and a secondary winding, a first inductance, an electronic conductive device having current carrying output terminal means and input terminal means for controlling the conductivity between said output terminal means, a first current path including the path between said output terminal means, said first inductance, and said primary winding connected in series across said source of direct current to conduct a flow of current from said source of direct current in said inductance and said primary winding, a first capacitor connected to be charged and discharged in synchronism with the operation of the engine, an asymmetrical conductive device poled to conduct an induced current How in said secondary winding that opposes the building up of the magnetic field of said transformer during the time that said current from said source of direct current is flowing in said inductance and said primary winding, said asymmetrical conductive device, said secondary winding and said capacitor being connected in series to charge said first capacitor by said inducted current, first control means connected across said input terminal means of said electronic conductive device to control the How of current from said source of direct current in said inductance and said primary winding in synchronism with the operation of the engine and to cause said latter current to be interrupted at substantially the same time or at a time approaching the same time that said first capacitor is charged, an electronic switch having current carrying output terminal means and input terminal means for controlling the conductivity of the path between said output terminals, a second inductance, a second capacitor operatively connected to fire said spark-discharge device, discharge means including a path provided by said output terminal means of said electronic switch, said second inductance, and said second capacitor being connected in series across said first capacitor to discharge said first capacitor through said second inductance into said second capacitor to cause a spark at said spark-discharge device, second control means connected to the control input terminal means of said electronic switch to control said discharge means in synchronism with the operation of the engine, and energy-disposing means connected to said transformer for disposing of the energy of the remaining magnetic fields of said transformer and said inductance.

6. An ignition system as defined in claim wherein said first control means and said second control means include in common a magnetic control device having a primary winding and two secondary windings one secondary winding being included in said first control means and the other secondary winding being included in said second control means and said magnetic control device being energized by current from said source of direct current conducted through said primary winding of said magnetic control device in synchronism with the operation of the engine.

7. An ignition system as defined in claim 5 wherein said discharge means includes a second secondary winding on said transformer connected across said second capacitor to discharge said second capacitor through said second secondary winding, and includes a third secondary winding on said transformer connected with said spark discharge device to cause a spark at said spark discharge device by an induced current in said third secondary winding.

8. An ignition system as defined in claim 7 wherein said first control means and said second control means include in common a magnetic control device having a primary winding and two secondary windings, one secondary winding being included in said first control means and the other secondary winding being included in said second control means and said magnetic control device being energized by current from said source of direct current conducted through said primary winding of said magnetic control device in synchronism with the operation of the engine.

9. A capacitor charging and discharging system for use in an ignition system adapted to ignite the combustible mixture of an internal combustion engine, said ignition system including a source of direct current, a spark discharge device, synchronizing means, and an ignition coil operatively connected with said spark discharge device, comprising in combination, a capacitor; step-up transformer means including a magnetic core, a primary winding, and a secondary winding; semiconductor means including output circuit means and input circuit means to control the conductivity of said output circuit means; means connected with said input circuit means to cause said output circuit means to become conductive in synchronism with the operation of the engine and to remain conductive until said capacitor is substantially charged; a first subcombination including said output circuit means and said primary winding operatively connected in series, said first sub-' combination being adapted to be connected across said source of direct current to permit current to flow in said primary winding when said output circuit means is conductive; a serniconductive diode; a second subcombination including said secondary winding, said capacitor, and said diode operatively connected in series to charge said capacitor by a current induced in said secondary winding by said forementioned current flowing in the said primary winding; magnetic field energy storage means operatively associated with said transformer means and so arranged as to store energy and to release energy during the time said forementioned current flows in said primary winding and in cooperation with said transformer means charging said capacitor, and said magnetic field energy storage means limiting the maximum value of the said forementioned current flowing in said primary winding; semiconductor switch means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; means connected with said input circuit means of said semiconductor switch means and being adapted to be connected with said synchronizing means to cause current to flow in synchronism with the operation of the engine, in said input circuit means of said semiconductor switch means; and a third subcombination including said output circuit means of said semiconductor switch means and said capacitor operatively connected in series, said third subcombination being adapted to be connected with said ignition coil to discharge said capacitor through said ignition coil to cause said spark discharge device to fire in synchronism with the operation of the engine.

10. A capacitor charging and discharging system as claimed in claim 9 wherein said semiconductor means comprising transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

11. A capacitor charging and discharging system as claimed in claim 10 wherein said magnetic field energy storage means comprises inductance means included in said first subcombination.

12. A capacitor charging and discharging system as claimed in claim 10 wherein said magnetic field energy storage means comprises inductance means included in said second subcombination.

13. A capacitor charging and discharging system as claimed in claim 9, and including means operatively associated with said transformer means to prevent any magnetic field in said transformer means, during the period said output circuit means of said semiconductor means is non-conductive, from causing harm to said semiconductor means.

14. A capacitor charging and discharging system as claimed in claim 13 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

15. A capacitor charging and discharging system as claimed in claim 14 wherein said magnetic field energy storage means comprises inductance means included in said first subcombination.

16. A capacitor charging and discharging system as claimed in claim 14 wherein said magnetic field energy storage means comprises inductance means included in said second subcombination,

17. A capacitor charging anddischarging system for use in an ignition system adapted to ignite the combustible mixture of an internal combustion engine, said ignition system including a source of direct current, a spark discharge device, synchronizing means, and an ignition coil operatively connected with said spark discharge device, comprising in combination, a capacitor connected to be charged and discharged; step-up transformer means including a magnetic core, a primary winding, and a secondary winding, said windings being disposed in relation to the said magnetic core and in relation to each other so as to have substantially maximum leakage inductances relative to the resistances of said windings, whereby said leakage inductances store energy and release energy to cooperate with the mutual magnetic flux in the said magnetic core to charge said capacitor, and said leakage inductances limiting the maximum value of the current that may flow in said primary winding from said source of direct current; means connected with said primary winding and said source of direct current to control the flow of current in said primary winding from said source of direct current, said last mentioned means permitting said current to flow in synchronism with the operation of said engine and not permitting said current to flow after said capacitor has been charged; a semiconductor diode; a first subcombination including said secondary winding, said diode, and said capacitor operatively connected in series to charge said capacitor by a current induced in said secondary winding by said forementioned current flowing in said primary winding; semiconductor switch means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; means connected with said input circuit means of said semiconductor switch means and being adapted to be connected with said synchronizing means to cause current to flow, in synchronism with the operation of the engine, in said input circuit means of said semiconductor switch means; and a second subcombination including said output circuit means of said semiconductor switch means and said capacitor operatively connected in series, said second subcombination being adapted to be connected with said ignition coil to discharge said capacitor through said ignition coil to cause said spark discharge device to fire in synchronism with the operation of the engine.

18. A capacitor charging and discharging system as claimed in claim 17 wherein said semiconductor switch means comprises silicon controlled rectifier means.

19. A capacitor charging and discharging system as claimed in claim 18 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

20. A capacitor charging and discharging system as claimed in claim 18 and in which said magnetic core, includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side and substantially filling said windows so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of the said windings.

21. A capacitor charging and discharging system as claimed in claim 17 and including means operatively associated with said transformer means to prevent any magnetic field in said transformer means, during the period said output circuit means of said semiconductor means is nonconductive, from causing harm to said semiconductor means.

22. A capacitor charging and discharging system as claimed in claim 21 wherein said semiconductor switch means comprises silicon controlled rectifier means.

23. A capacitor charging and discharging system as claimed in claim 22 and in .which said magnetic core includes two spaced parallel windows, having axial lengthsgreater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

24. A capacitor charging and discharging system as claimed in claim 22 and in which said magnetic core includes two spaced paraliel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-byside, and substantially filling said windows so as to cause said windings to have said substantially maximum leakage inductances relative to the -resistances of the said windings.

25.'A capacitor charging and discharging system for use in an ignition system adapted to ignite the combustible mixture of an internal combustion engine, said ignition system including a source of direct current, a spark discharge device, synchronizing means, and an ignition coil operatively connected with said spark discharge device, comprising in combination, step-up transformer means. including a magnetic core, a primary winding, and a secondary winding; semiconductor means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; a first subcombination including said output circuit means and said primary winding operatively connected in series, said first subcombination being adapted to be connected across said source of direct current to permit, when said output circuit means is conductive, a current to flow in said primary winding to energize said transformer means; a capacitor; a semiconductor diode; a second subcombination including said capacitor, said diode, said secondary winding, and said input circuit means operatively connected in series, said second subcombination being so arranged as to be connected with said source of direct current when said first subcombination is connected with said source of direct current to thereby cause, afier said capacitor is discharged, a current to flow in said input circuit means which current causes said output circuit means to be conductive which permits said transformer means to be energized and thus causes said last mentioned current to continue to flow until said capacitor is recharged; magnetic field energy storage means operatively associated with said transformer means and so arranged as to store energy and to release energy during the time said forementioned current flows in said primary winding and in cooperation with said transformer means charging said capacitor, and said magnetic field energy storage means limiting the maximum value of the said forementioned current flowing in said primary winding; semiconductor switch means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; means connected with said input circuit means of said semiconductor switch means and being adapted to be connected with said synchronizing means to cause current to flow, in synchronism with the operation of the engine, in said input circuit means of said semiconductor switch means; and a third subcombination including said output circuit means of said semiconductor switch means and said capacitor operatively connected in series, said third subcombination being adapted to be connected with said ignition coil to discharge said capacitor through said ignition coil to cause said spark discharge device to fire in synchronism with the operation of the engine.

26. A capacitor charging and discharging system as claimed in claim .25 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

27. A capacitor charging and discharging system as claimed in claim 26 wherein said magnetic field energy storage means comprises inductance means included in said second subcombination.

28. A capacitor charging and discharging system as claimed in claim 25, and including means operatively associated with said transformer means to prevent any magnetic field in said transformer means, during the period said output circuit means of said semiconductor means is nonconductive, from causing harm to said semiconductor means.

29. A capacitor charging and discharging system as claimed in claim 28 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

30. A capacitor charging and discharging system as claimed in claim 29 wherein said magnetic field energy storage means comprises inductance means included in said second subcombination.

31. A capacitor charging and discharging system for use' in an ignition system adapted to ignite the combustible mixture of an internal combustion engine, said ignition system including a source of direct current, a spark discharge device, synchronizing means, and an ignition coil operatively connected with said spark discharge device, comprising in com bination, a capacitor connected to be charged and discharged; step'up transformer means including a magnetic core, a primary winding, and a secondary winding, said windings being disposed in relation to the said magnetic core and in relation to each other so as to have substantially maximum leakage inductances relative to the resistances of said windings, whereby said leakage inductances store energy and release energy to cooperate with the mutual magnetic flux in the said magnetic core to charge said capacitor, and said leakage inductances limiting the maximum value of the current that may flow in said primary winding from said source of direct current; semiconductor means including output circuit means and input circuit means to control the conductivity of said output circuit means; a first subcombination including said output circuit means and said primary winding operatively connected in series, said first subcombination being adapted to be connected across said source of direct current to permit, when said output circuit means is conductive, a current to flow in said primary winding to energize said transformer means; a semiconductor diode; a second subcombination including said capacitor, said diode, said secondary winding, and said input circuit means operatively connected in series, said second subcombination being so arranged as to be connected with said source of direct current when said first subcombination is connected with said source of direct current to thereby cause, after said capacitor is discharged, a current to flow in said input circuit means which current causes aid outputv circuit means to be conductive which permits said transformer means to be energized and thus causes said last mentioned current to continue to flow until said capacitor is recharged; semiconductor switch means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; means connected with said input circuit means of said semi-conductor switch means and being adapted to be connected with said synchronizing means to cause current to flow, in synchronism with the operation of the engine, in said input circuit means of said semiconductor switch means; and a third subcombination including said output circuit means of said semiconductor switch means and said capacitor operatively connected in series, said third subcombination being adapted to be connected with said ignition coil to discharge said capacitor through said ignition coil to cause said spark discharge device to fire in synchronism with the operation of the engine.

32. A capacitor charging and discharging system as claimed in claim 31 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

33. A capacitor charging and discharging system as claimed in claim 32 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

34. A capacitor charging and discharging system as claimed in claim 32 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side and substantially filling said windows so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

35. A capacitor charging and discharging system as claimed in claim 31, and including means operatively associated with said transformer means to prevent any magnetic field in said transformer means, during the period said output circuit means of said semiconductor means is nonconductive, from causing harm to said semiconductor means.

36. A capacitor charging and discharging system as claimed in claim 35 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

37. A capacitor charging and discharging system as claimed in claim 36 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

38. A capacitor charging and discharging system as claimed in claim 36 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side and substantially filling said windows so as tocause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

39. A capacitor charging and discharging system for use in an ignition system adapted to ignite the combustible mixture of an internal combustion engine, said ignition system including a source of direct current, a spark discharge device, synchronizing means, and an ignition coil operatively connected with said spark discharge device, comprising in combination, step-up transformer means including a magnetic core, a primary winding, and a secondary winding; semiconductor means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; a first subcombination including said output circuit means and said primary winding operatively connected in series, said first subcombination being adapted to be connected across said source of direct current to permit, when said output circuit means is conductive, a current to flow in said primary winding to energize said transformer means; a capacitor; a semiconductor diode; a second subcombination including said capacitor, said semiconductor diode, said secondary winding, and said input circuit means operatively connected in series, said second subcombination being so arranged as to be connected with said source of direct current when said first subcombination is connected with said source of direct current to thereby cause, if said capacitor happens to be uncharged when said first subcombination is connected with said source of direct current, a current to immediately flow in said input circuit means which current causes said output circuit means to be conductive which permits said transformer means to be energized and thus causes said last mentioned current to continue to flow until said capacitor is charged; semiconductor switch means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; means connected with said input circuit means of said semiconductor switch means and being adapted to be connected with said synchronizing means to cause current to flow, in synchronism with the operation of the engine, in said input circuit means of said semiconductor switch means; and a third subcombination including said output circuit means of said semiconductor switch means and said capacitor operatively connected in series, said third subcombination being adapted to be connected with said ignition coil to discharge said capacitor through said ignition coil to cause said spark discharge device to fire in synchronism with the operation of the engine.

40. A capacitor charging and discharging system as claimed in claim 39 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

41. A capacitor charging and discharging system as claimed in claim 39, and including means operatively associated with said transformer means to prevent any magnetic field in said transformer means, during the period said output circuit means of said semiconductor means is nonconductive, from causing harm to said semiconductor means.

42. A capacitor charging and discharging system as claimed in claim 41 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

43. A capacitor charging and discharging system as claimed in claim 32 and including a second semiconductor diode operatively connected across said input circuit means of said transistor means and in which said third subcornbination includes said second semiconductor diode.

44. A capacitor charging and discharging system as claimed in claim 43 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights and in which said primary winding and said secondary winding are disposed side-by-side so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

45. A capacitor charging and discharging system as claimed in claim 43 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side and substantially filling said windows so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

46. A capacitor charging and discharging system as claimed in claim 36 and including a second semiconductor diode operatively connected across said input circuit means of said transistor means and in which said third subcornbination includes said second semiconductor diode.

47. A capacitor charging and discharging system as claimed in claim 46 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights and in which said primary winding and said secondary winding are disposed side-by-side so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

48. A capacitor charging and discharging system as claimed in claim 46 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side and substantially filling said windows so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

49. A capacitor charging and discharging system as claimed in claim 40 and including a second semiconductor diode operatively connected across said input circuit means of said transistor means and in which said third subcornbination includes said second semiconductor diode.

50. A capacitor charging and discharging system as claimed in claim 49 and in which said windings have substantially maximum leakage inductances relative to the resistances of said windings whereby said leakage inductances store energy and release energy to cooperate with the mutual magnetic flux in tee said magnetic core to charge said capacitor, and said leakage inductances limiting the maximum value of the current that may flow in said primary winding from said source of direct current.

51. A capacitor charging and discharging system as claimed in claim 49 and in which said first subcornbination includes an inductance operatively connected in series with said output circuit means of said semiconductor means and said primary winding whereby said inductance. stores energy and releases energy to cooperate with said transformer means to charge said capacitor, and said inductance limiting the maximum value of current that may flow in said primary winding from said source of direct current.

52. A capacitor charging and discharging system as claimed in claim 49 and in which said second subcornbination includes an inductance operatively connected in series with said capacitor, said first semiconductor diode, said secondary winding, and said input circuit means-of said semiconductor means whereby saidinductance stores energy and releases energy to cooperate with said transformer means to charge said capacitor, and said inductance limiting the maximum value of current that may flow in said primary winding from said source of direct current.

53. A capacitor charging andv discharging system as claimed in claim 42 and including a second semiconductor diode operatively connected across said input circuit means of said transistor means and in which said third subcornbination includes said second semiconductor diode.

54. A capacitor charging and discharging system as claimed in claim 53 and in which said windings have substantially maximum leakage inductances relative to the resistances of said windings whereby said leakage-inductances store energy and release energy to cooperate with the mutual magnetic flux in the said magnetic core to charge said capacitor, and said leakage inductances limiting the maximum value of the cur.- rent that may flow in said primary winding from said source of direct current.

55. A capacitor charging and discharging system as claimed in claim 53 and in which said first subcornbination includes an inductance operatively connected in series with said outputv circuit means of said semiconductor means and said primary winding whereby said inductance stores energy and releases energy to cooperate with said transformer means to charge said capacitor, and said inductance limiting the maximum value of current that may flow in said primary winding from said source of direct current.

56. A capacitor charging and discharging system as claimed in claim 53 and in which said second subcornbination includes an inductance operatively connected in series with said capacitor, said first semiconductor diode, said secondary winding, and said input circuit means of said semiconductor means whereby said inductance stores energy and releases energy to cooperate with said transformer means to charge said capacitor, and said inductance limiting the maximum value of current that may flow in said primary winding from said source of direct current.

57. A capacitor charging and discharging system as claimed in claim 36 and including a second semiconductor diode operatively connected across said input circuit means of said transistor means and in which said third subcornbination includes said second semiconductor diode, and further including an inductance and a third semiconductor diode operatively connected in series, said inductance and third semiconductor diode in series being operatively connected across said capacitor to provide a partial recharging of said capacitor.

Claims (57)

1. An ignition system for igniting the combustible mixture of an internal combustion engine and including a source of direct current and a spark discharge device and comprising in combination, a transformer having a primary winding and three secondary windings, namely a first secondary winding, a second secondary winding, and a third secondary winding, an electronic conductive device having current carrying output terminal means and having input terminal means for controlling the conductivity of the path oF current flow between said output terminal means, a first current path including the path between said output terminal means and said primary winding connected across the source of direct current to conduct a flow of current from the source of direct current through said primary winding, an asymmetrical conductive device poled to conduct a first induced current flow in said first secondary winding that opposes the building up of the magnetic field of said transformer during the time that current from said source of direct current is flowing in said primary winding, a first capacitor connected to be charged and discharged in synchronism with the operation of the engine, a second current path including said first secondary winding and said asymmetrical conductive device connected in series across said first capacitor to charge said first capacitor by said first induced current, first control means connected to said input terminal means of said electronic conductive device to control the flow of current from said source of direct current in said primary winding in synchronism with the operation of the engine and to cause to be interrupted said latter current flow at substantially the same time or at a time approaching the same time that said first capacitor is charged, an electronic switch having current carrying output terminal means and input terminal means to control the conductivity of the path between said output terminal means, an inductance, a second capacitor, discharge means including the path between said output terminal means of said electronic switch, said inductance and said second capacitor connected in series across said first capacitor and said second capacitor also connected in parallel with said second secondary winding and including said third secondary winding connected with said spark discharge device to discharge said first capacitor through said inductance into said second capacitor thereby causing a voltage on said second capacitor and said second secondary winding which causes a second induced current to flow in said third secondary winding to produce a spark at said spark discharge device, and second control means connected to the said input terminal means of said electronic switch to control the conductivity of the path between said output terminal means in synchronism with the operation of the engine.

2. An ignition system as defined in claim 1 wherein said first control means and said second control means include in common a magnetic control device having a primary winding and two secondary windings, one secondary winding being included in said first control means and the other secondary winding being included in said second control means and said magnetic control device being energized by current from said source of direct current conducted through said primary winding of said magnetic control device in synchronism with the operation of the engine.

3. An ignition system as defined in claim 1 wherein said electronic conductive device is a transistor, said asymmetrical conductive device is a semi-conductor diode, and said electronic switch is a thyratron tube.

4. An ignition system as defined in claim 1 wherein said electronic conductive device is a transistor, said asymmetrical device is a semi-conductor diode, and said electronic switch is a silicon controlled rectifier.

5. An ignition system for igniting the combustible mixture of an internal combustion engine and including a source of direct current and a spark-discharge device and comprising in combination a transformer having a primary winding and a secondary winding, a first inductance, an electronic conductive device having current carrying output terminal means and input terminal means for controlling the conductivity between said output terminal means, a first current path including the path between said output terminal means, said first inductance, and said primary winding connected in series across said source of direct current to conduct a flow of current from said source of direct current in said inductance and said primary winding, a first capacitor connected to be charged and discharged in synchronism with the operation of the engine, an asymmetrical conductive device poled to conduct an induced current flow in said secondary winding that opposes the building up of the magnetic field of said transformer during the time that said current from said source of direct current is flowing in said inductance and said primary winding, said asymmetrical conductive device, said secondary winding and said capacitor being connected in series to charge said first capacitor by said inducted current, first control means connected across said input terminal means of said electronic conductive device to control the flow of current from said source of direct current in said inductance and said primary winding in synchronism with the operation of the engine and to cause said latter current to be interrupted at substantially the same time or at a time approaching the same time that said first capacitor is charged, an electronic switch having current carrying output terminal means and input terminal means for controlling the conductivity of the path between said output terminals, a second inductance, a second capacitor operatively connected to fire said spark-discharge device, discharge means including a path provided by said output terminal means of said electronic switch, said second inductance, and said second capacitor being connected in series across said first capacitor to discharge said first capacitor through said second inductance into said second capacitor to cause a spark at said spark-discharge device, second control means connected to the control input terminal means of said electronic switch to control said discharge means in synchronism with the operation of the engine, and energy-disposing means connected to said transformer for disposing of the energy of the remaining magnetic fields of said transformer and said inductance.

6. An ignition system as defined in claim 5 wherein said first control means and said second control means include in common a magnetic control device having a primary winding and two secondary windings one secondary winding being included in said first control means and the other secondary winding being included in said second control means and said magnetic control device being energized by current from said source of direct current conducted through said primary winding of said magnetic control device in synchronism with the operation of the engine.

7. An ignition system as defined in claim 5 wherein said discharge means includes a second secondary winding on said transformer connected across said second capacitor to discharge said second capacitor through said second secondary winding, and includes a third secondary winding on said transformer connected with said spark discharge device to cause a spark at said spark discharge device by an induced current in said third secondary winding.

8. An ignition system as defined in claim 7 wherein said first control means and said second control means include in common a magnetic control device having a primary winding and two secondary windings, one secondary winding being included in said first control means and the other secondary winding being included in said second control means and said magnetic control device being energized by current from said source of direct current conducted through said primary winding of said magnetic control device in synchronism with the operation of the engine.

9. A capacitor charging and discharging system for use in an ignition system adapted to ignite the combustible mixture of an internal combustion engine, said ignition system including a source of direct current, a spark discharge device, synchronizing means, and an ignition coil operatively connected with said spark discharge device, comprising in combination, a capacitor; step-up transformer means including a magnetic core, a primary winding, and a secondary winding; semiconductor meanS including output circuit means and input circuit means to control the conductivity of said output circuit means; means connected with said input circuit means to cause said output circuit means to become conductive in synchronism with the operation of the engine and to remain conductive until said capacitor is substantially charged; a first subcombination including said output circuit means and said primary winding operatively connected in series, said first subcombination being adapted to be connected across said source of direct current to permit current to flow in said primary winding when said output circuit means is conductive; a semiconductive diode; a second subcombination including said secondary winding, said capacitor, and said diode operatively connected in series to charge said capacitor by a current induced in said secondary winding by said forementioned current flowing in the said primary winding; magnetic field energy storage means operatively associated with said transformer means and so arranged as to store energy and to release energy during the time said forementioned current flows in said primary winding and in cooperation with said transformer means charging said capacitor, and said magnetic field energy storage means limiting the maximum value of the said forementioned current flowing in said primary winding; semiconductor switch means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; means connected with said input circuit means of said semiconductor switch means and being adapted to be connected with said synchronizing means to cause current to flow in synchronism with the operation of the engine, in said input circuit means of said semiconductor switch means; and a third subcombination including said output circuit means of said semiconductor switch means and said capacitor operatively connected in series, said third subcombination being adapted to be connected with said ignition coil to discharge said capacitor through said ignition coil to cause said spark discharge device to fire in synchronism with the operation of the engine.

10. A capacitor charging and discharging system as claimed in claim 9 wherein said semiconductor means comprising transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

11. A capacitor charging and discharging system as claimed in claim 10 wherein said magnetic field energy storage means comprises inductance means included in said first subcombination.

12. A capacitor charging and discharging system as claimed in claim 10 wherein said magnetic field energy storage means comprises inductance means included in said second subcombination.

13. A capacitor charging and discharging system as claimed in claim 9, and including means operatively associated with said transformer means to prevent any magnetic field in said transformer means, during the period said output circuit means of said semiconductor means is non-conductive, from causing harm to said semiconductor means.

14. A capacitor charging and discharging system as claimed in claim 13 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

15. A capacitor charging and discharging system as claimed in claim 14 wherein said magnetic field energy storage means comprises inductance means included in said first subcombination.

16. A capacitor charging and discharging system as claimed in claim 14 wherein said magnetic field energy storage means comprises inductance means included in said second subcombination.

17. A capacitor charging and discharging system for use in an ignition system adapted to ignite the combustible mixture of an internal combustion engine, said ignition system including a source of direct current, a spark discharge device, synchronizing means, and an ignition coil operatively connected with said spark dischArge device, comprising in combination, a capacitor connected to be charged and discharged; step-up transformer means including a magnetic core, a primary winding, and a secondary winding, said windings being disposed in relation to the said magnetic core and in relation to each other so as to have substantially maximum leakage inductances relative to the resistances of said windings, whereby said leakage inductances store energy and release energy to cooperate with the mutual magnetic flux in the said magnetic core to charge said capacitor, and said leakage inductances limiting the maximum value of the current that may flow in said primary winding from said source of direct current; means connected with said primary winding and said source of direct current to control the flow of current in said primary winding from said source of direct current, said last mentioned means permitting said current to flow in synchronism with the operation of said engine and not permitting said current to flow after said capacitor has been charged; a semiconductor diode; a first subcombination including said secondary winding, said diode, and said capacitor operatively connected in series to charge said capacitor by a current induced in said secondary winding by said forementioned current flowing in said primary winding; semiconductor switch means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; means connected with said input circuit means of said semiconductor switch means and being adapted to be connected with said synchronizing means to cause current to flow, in synchronism with the operation of the engine, in said input circuit means of said semiconductor switch means; and a second subcombination including said output circuit means of said semiconductor switch means and said capacitor operatively connected in series, said second subcombination being adapted to be connected with said ignition coil to discharge said capacitor through said ignition coil to cause said spark discharge device to fire in synchronism with the operation of the engine.

18. A capacitor charging and discharging system as claimed in claim 17 wherein said semiconductor switch means comprises silicon controlled rectifier means.

19. A capacitor charging and discharging system as claimed in claim 18 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

20. A capacitor charging and discharging system as claimed in claim 18 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side and substantially filling said windows so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of the said windings.

21. A capacitor charging and discharging system as claimed in claim 17 and including means operatively associated with said transformer means to prevent any magnetic field in said transformer means, during the period said output circuit means of said semiconductor means is nonconductive, from causing harm to said semiconductor means.

22. A capacitor charging and discharging system as claimed in claim 21 wherein said semiconductor switch means comprises silicon controlled rectifier means.

23. A capacitor charging and discharging system as claimed in claim 22 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

24. A capacitor charging and discharging system as claimed in claim 22 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side and substantially filling said windows so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of the said windings.

25. A capacitor charging and discharging system for use in an ignition system adapted to ignite the combustible mixture of an internal combustion engine, said ignition system including a source of direct current, a spark discharge device, synchronizing means, and an ignition coil operatively connected with said spark discharge device, comprising in combination, step-up transformer means including a magnetic core, a primary winding, and a secondary winding; semiconductor means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; a first subcombination including said output circuit means and said primary winding operatively connected in series, said first subcombination being adapted to be connected across said source of direct current to permit, when said output circuit means is conductive, a current to flow in said primary winding to energize said transformer means; a capacitor; a semiconductor diode; a second subcombination including said capacitor, said diode, said secondary winding, and said input circuit means operatively connected in series, said second subcombination being so arranged as to be connected with said source of direct current when said first subcombination is connected with said source of direct current to thereby cause, after said capacitor is discharged, a current to flow in said input circuit means which current causes said output circuit means to be conductive which permits said transformer means to be energized and thus causes said last mentioned current to continue to flow until said capacitor is recharged; magnetic field energy storage means operatively associated with said transformer means and so arranged as to store energy and to release energy during the time said forementioned current flows in said primary winding and in cooperation with said transformer means charging said capacitor, and said magnetic field energy storage means limiting the maximum value of the said forementioned current flowing in said primary winding; semiconductor switch means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; means connected with said input circuit means of said semiconductor switch means and being adapted to be connected with said synchronizing means to cause current to flow, in synchronism with the operation of the engine, in said input circuit means of said semiconductor switch means; and a third subcombination including said output circuit means of said semiconductor switch means and said capacitor operatively connected in series, said third subcombination being adapted to be connected with said ignition coil to discharge said capacitor through said ignition coil to cause said spark discharge device to fire in synchronism with the operation of the engine.

26. A capacitor charging and discharging system as claimed in claim 25 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

27. A capacitor charging and discharging system as claimed in claim 26 wherein said magnetic field energy storage means comprises inductance means included in said second subcombination.

28. A capacitor charging and discharging system as claimed in claim 25, and including means operatively associated with said transformer means to prevent any magnetic field in said transformer means, durinG the period said output circuit means of said semiconductor means is nonconductive, from causing harm to said semiconductor means.

29. A capacitor charging and discharging system as claimed in claim 28 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

30. A capacitor charging and discharging system as claimed in claim 29 wherein said magnetic field energy storage means comprises inductance means included in said second subcombination.

31. A capacitor charging and discharging system for use in an ignition system adapted to ignite the combustible mixture of an internal combustion engine, said ignition system including a source of direct current, a spark discharge device, synchronizing means, and an ignition coil operatively connected with said spark discharge device, comprising in combination, a capacitor connected to be charged and discharged; step-up transformer means including a magnetic core, a primary winding, and a secondary winding, said windings being disposed in relation to the said magnetic core and in relation to each other so as to have substantially maximum leakage inductances relative to the resistances of said windings, whereby said leakage inductances store energy and release energy to cooperate with the mutual magnetic flux in the said magnetic core to charge said capacitor, and said leakage inductances limiting the maximum value of the current that may flow in said primary winding from said source of direct current; semiconductor means including output circuit means and input circuit means to control the conductivity of said output circuit means; a first subcombination including said output circuit means and said primary winding operatively connected in series, said first subcombination being adapted to be connected across said source of direct current to permit, when said output circuit means is conductive, a current to flow in said primary winding to energize said transformer means; a semiconductor diode; a second subcombination including said capacitor, said diode, said secondary winding, and said input circuit means operatively connected in series, said second subcombination being so arranged as to be connected with said source of direct current when said first subcombination is connected with said source of direct current to thereby cause, after said capacitor is discharged, a current to flow in said input circuit means which current causes aid output circuit means to be conductive which permits said transformer means to be energized and thus causes said last mentioned current to continue to flow until said capacitor is recharged; semiconductor switch means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; means connected with said input circuit means of said semi-conductor switch means and being adapted to be connected with said synchronizing means to cause current to flow, in synchronism with the operation of the engine, in said input circuit means of said semiconductor switch means; and a third subcombination including said output circuit means of said semiconductor switch means and said capacitor operatively connected in series, said third subcombination being adapted to be connected with said ignition coil to discharge said capacitor through said ignition coil to cause said spark discharge device to fire in synchronism with the operation of the engine.

32. A capacitor charging and discharging system as claimed in claim 31 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

33. A capacitor charging and discharging system as claimed in claim 32 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

34. A capacitor charging and discharging system as claimed in claim 32 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side and substantially filling said windows so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

35. A capacitor charging and discharging system as claimed in claim 31, and including means operatively associated with said transformer means to prevent any magnetic field in said transformer means, during the period said output circuit means of said semiconductor means is nonconductive, from causing harm to said semiconductor means.

36. A capacitor charging and discharging system as claimed in claim 35 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

37. A capacitor charging and discharging system as claimed in claim 36 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

38. A capacitor charging and discharging system as claimed in claim 36 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side and substantially filling said windows so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

39. A capacitor charging and discharging system for use in an ignition system adapted to ignite the combustible mixture of an internal combustion engine, said ignition system including a source of direct current, a spark discharge device, synchronizing means, and an ignition coil operatively connected with said spark discharge device, comprising in combination, step-up transformer means including a magnetic core, a primary winding, and a secondary winding; semiconductor means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; a first subcombination including said output circuit means and said primary winding operatively connected in series, said first subcombination being adapted to be connected across said source of direct current to permit, when said output circuit means is conductive, a current to flow in said primary winding to energize said transformer means; a capacitor; a semiconductor diode; a second subcombination including said capacitor, said semiconductor diode, said secondary winding, and said input circuit means operatively connected in series, said second subcombination being so arranged as to be connected with said source of direct current when said first subcombination is connected with said source of direct current to thereby cause, if said capacitor happens to be uncharged when said first subcombination is connected with said source of direct current, a current to immediately flow in said input circuit means which current causes said output circuit means to be conductive which permits said transformer means to be energized and thus causes said last mentioned current to continue to flow until said capacitor is charged; semiconductor switch means including output circuit means and input circuit means to cause said output circuit means to be conductive when current flows in said input circuit means; means connected with said input circuit means of said semiconductor switch means and being adapted to be connected With said synchronizing means to cause current to flow, in synchronism with the operation of the engine, in said input circuit means of said semiconductor switch means; and a third subcombination including said output circuit means of said semiconductor switch means and said capacitor operatively connected in series, said third subcombination being adapted to be connected with said ignition coil to discharge said capacitor through said ignition coil to cause said spark discharge device to fire in synchronism with the operation of the engine.

40. A capacitor charging and discharging system as claimed in claim 39 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

41. A capacitor charging and discharging system as claimed in claim 39, and including means operatively associated with said transformer means to prevent any magnetic field in said transformer means, during the period said output circuit means of said semiconductor means is nonconductive, from causing harm to said semiconductor means.

42. A capacitor charging and discharging system as claimed in claim 41 wherein said semiconductor means comprises transistor means and said semiconductor switch means comprises silicon controlled rectifier means.

43. A capacitor charging and discharging system as claimed in claim 32 and including a second semiconductor diode operatively connected across said input circuit means of said transistor means and in which said third subcombination includes said second semiconductor diode.

44. A capacitor charging and discharging system as claimed in claim 43 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights and in which said primary winding and said secondary winding are disposed side-by-side so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

45. A capacitor charging and discharging system as claimed in claim 43 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side and substantially filling said windows so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

46. A capacitor charging and discharging system as claimed in claim 36 and including a second semiconductor diode operatively connected across said input circuit means of said transistor means and in which said third subcombination includes said second semiconductor diode.

47. A capacitor charging and discharging system as claimed in claim 46 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights and in which said primary winding and said secondary winding are disposed side-by-side so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

48. A capacitor charging and discharging system as claimed in claim 46 and in which said magnetic core includes two spaced parallel windows, having axial lengths greater than their heights, and in which said primary winding and said secondary winding are disposed side-by-side and substantially filling said windows so as to cause said windings to have said substantially maximum leakage inductances relative to the resistances of said windings.

49. A capacitor charging and discharging system as claimed in claim 40 and including a second semiconductor diode operatively connected across said input circuit means of said transistor means and in which said third subcombination includes said second semiconductor diode.

50. A capacitor charging and discharging system as claimed in claim 49 and in which said windings have substantially maximum leakage inductances relative to the resistances of said windiNgs whereby said leakage inductances store energy and release energy to cooperate with the mutual magnetic flux in tee said magnetic core to charge said capacitor, and said leakage inductances limiting the maximum value of the current that may flow in said primary winding from said source of direct current.

51. A capacitor charging and discharging system as claimed in claim 49 and in which said first subcombination includes an inductance operatively connected in series with said output circuit means of said semiconductor means and said primary winding whereby said inductance stores energy and releases energy to cooperate with said transformer means to charge said capacitor, and said inductance limiting the maximum value of current that may flow in said primary winding from said source of direct current.

52. A capacitor charging and discharging system as claimed in claim 49 and in which said second subcombination includes an inductance operatively connected in series with said capacitor, said first semiconductor diode, said secondary winding, and said input circuit means of said semiconductor means whereby said inductance stores energy and releases energy to cooperate with said transformer means to charge said capacitor, and said inductance limiting the maximum value of current that may flow in said primary winding from said source of direct current.

53. A capacitor charging and discharging system as claimed in claim 42 and including a second semiconductor diode operatively connected across said input circuit means of said transistor means and in which said third subcombination includes said second semiconductor diode.

54. A capacitor charging and discharging system as claimed in claim 53 and in which said windings have substantially maximum leakage inductances relative to the resistances of said windings whereby said leakage inductances store energy and release energy to cooperate with the mutual magnetic flux in the said magnetic core to charge said capacitor, and said leakage inductances limiting the maximum value of the current that may flow in said primary winding from said source of direct current.

55. A capacitor charging and discharging system as claimed in claim 53 and in which said first subcombination includes an inductance operatively connected in series with said output circuit means of said semiconductor means and said primary winding whereby said inductance stores energy and releases energy to cooperate with said transformer means to charge said capacitor, and said inductance limiting the maximum value of current that may flow in said primary winding from said source of direct current.

56. A capacitor charging and discharging system as claimed in claim 53 and in which said second subcombination includes an inductance operatively connected in series with said capacitor, said first semiconductor diode, said secondary winding, and said input circuit means of said semiconductor means whereby said inductance stores energy and releases energy to cooperate with said transformer means to charge said capacitor, and said inductance limiting the maximum value of current that may flow in said primary winding from said source of direct current.

57. A capacitor charging and discharging system as claimed in claim 36 and including a second semiconductor diode operatively connected across said input circuit means of said transistor means and in which said third subcombination includes said second semiconductor diode, and further including an inductance and a third semiconductor diode operatively connected in series, said inductance and third semiconductor diode in series being operatively connected across said capacitor to provide a partial recharging of said capacitor.

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