US2966615A

US2966615A - Ignition system

Info

Publication number: US2966615A
Application number: US706613A
Authority: US
Inventors: Jr Earl W Meyer; Naborowski John Gregory; Robert J Latorre
Original assignee: Electric Auto Lite Co
Current assignee: Electric Auto Lite Co
Priority date: 1958-01-02
Filing date: 1958-01-02
Publication date: 1960-12-27
Anticipated expiration: 1977-12-27

Description

1960 E. w. MEYER, JR., ETAL 2,966,615

IGNITION SYSTEM 2 Sheets-Sheet 1 Filed Jan. 2, 1958 will:

ENTORS.

JOH ROWSKI ROBERT J. LATORRE MMMM i ll ll v hl ATTORNEYS Dec. 27, 1960 E. W. MEYER, JR., ETAL IGNITION SYSTEM 2 Sheets-Sheet 2 Filed Jan. 2, 1958 WWI INVENTORS. EARL W. MEYER JR. JOHN G. NABORO ROB WSKI ERT J. LATORRE Un ted Stew Patt fl jQ 2,966,615 IGNITION SYSTEM Earl W. Meyer, Jr., John Gregory Naborowski, and

9 Claims. (Cl. 315-206) This invention relates to electrical apparatus, and more particularly to electrical circuits and devices connected therein for producing electrical spark discharges such as those adapted for use in systems for igniting combustible charges in multi-cylinder internal combustion engines subjected to variable operating conditions of load and speed.

The invention comprehends a novel and long-lasting electrical system for producing high energy spark discharges after the interruption of relatively high input currents by the utilization of semi-conductor devices commonly known as transistors in association with a magnetically very close coupled low inductance ignition coil having a low primary kick-back voltage.

The invention comprises an ignition system for producing a very effective discharge through the output circuit to the spark plugs of multi-cylinder highcompression engines, avoiding the decrease of life of the make and break or timing apparatus.

The invention contemplates an electrical system of extremely stable characteristics, wherein a relatively low voltage is employed to produce a high input current in order to obtain an effective high energy spark discharge, minimizing. the possibility of electrical failure normally present in conventional systems where a high 'input current is used.

The invention embraces an electrical ignition system incorporating means for effectively interrupting high currents in the primary circuit of an ignition coil, avoiding the deleterious effects caused by the formation in cold weather of objetcionable oxides and surface films on the make and break contact points, causing, what is commonly known as, blue points.

The invention includes the utilization in a novel electrical circuit semi-conductor devices, commonly known as transistors, for establishing and interrupting the application to relatively high electric current to the primary circuit of an ignition system by means actuated in timed relation with the engine.

According to the foregoing summary of the invention indicating the general nature and substance, its main objective is to provide an electrical system including a novel electrical circuit incorporating a semi-conductor device or transistor to control the application as well as the interruption of the flow of the current required for the energization of the primary winding of a low inductance ignition coil having a very high coupling coeflicient and very low primary circuit kick-back voltage for producing electrical spark discharges for igniting the combustible charges in multi-cylinder high compression engines subjected to variable operating conditions of load and speed.

Conventional ignition systems for multi-cylinder high compression engines have been unsatisfactory for prolonged operations due to the lack of stability and exceedingly short life of the make and break mechanism. The attainment of constant characteristics and prolongation of the elfective life of the make and break contacts present many problems which require, for their solutions, careful evaluation of many complex and variable factors. This is particularly true in connection with ignition mechanisms for high speed, high compression, variable speed internal combustion engines, and many attempts to solve this problem have been unsuccessful, so that the comparative life of the conventional make and break mechanisms is of comparatively short duration.

One of the principal objects of the invention is to avoid the foregoing drawbacks and produce a very reliable high energy ignition system of extremely stable characteristics and long-lasting life for use with high compression multi-cylinder engines subjected to variable operating conditions of load and speed.

Another object of this invention is to provide a novel make and break timing mechanism for ignition systems, in which a semi-conductor or transistor is used to perform the current-switching function of the conventional make and break contacts by merely applying a low current signal to the transistor in predetermined timed relation with the engine.

Another object of the invention is to provide a novel current switching apparatus for an ignition system capable of use with present day distributors by replacing the conventional ignition coil by a transistor interconnected with an'ignition coil having very closely coupled primary and secondary windings with a primary of relatively low inductance, whereby the conventional distributor contacts only perform the function of periodically applying v a very low current to the transistor in timed relation with the engine to'accomplish through the transistor the switching or the application and interruption of the current required for the energization of the ignition coil.

Another object of this invention is to provide an ignition system in which extremely small. currents are used for controlling and timing the high electrical energy used in the system for producing an effective igniting or firing spark at the spark plug electrodes.

.Another object of this inventionis to provide anignition system in which currents of high magnitude are used to increase or intensify the spark discharge without detrimental effects in the timing mechanism or the life of the make and break contacts.

Another object of this invention is to provide an ignition timing or controlling mechanism using a transistor for effectively interrupting a relatively high current in the primary circuit of an ignition coil without producing thereto in predetermined timed relation with the engine,

thereby avoiding the drawbacks of objectionable decrease in the energization of the coil at high engine speeds.

A further object of this invention is to provide an electrical system in which currents of high magnitude provided by a current source for current-consuming devices are interrupted by utilizing a transistor which performs the energizing currents on or oil" switching function by a simple controlling circuit using said current source.

A further object of the invention is to provide an electrical circuit for controlling a transistor as on or off means for the flow of currents of high magnitude without impairing its characteristics or decreasing its effective operating life.

Other objects and advantages of this invention relating to the arrangement, operation and function of the related elements of the structure, to various details of construction, to combinations of parts and to economics of manufacture, will be apparent to those skilled in the art upon consideration of the following description and appended claims, reference being had to the accompanying draw- 4 ings forming a part of this specification wherein like t ied Dee-- 1: 6

reference characters designate corresponding parts in the several views.

Referring to the drawings:

Fig. I is a schematic circuit diagram of an ignition system embodying the principles of the invention;

Fig. II is a schematic circuit diagram of another form of an ignition system utilizing the principles of the invention;

Fig. III is a schematic circuit diagram illustrating an ignition system incorporating the principles of the invention; and

Fig. IV is a schematic circuit diagram of a modified form of an ignition system incorporating the principles of the invention.

The present invention may be incorporated in any suitable type of ignition system and devices for producing electrical discharge to ignite combustible mixtures and, for practical application of its principles, the same is shown in the drawings as embodied in ignition systems for use with internal combustion engines subjected to variable conditions of load and speed.

Referring particularly to Fig. I of the drawings, a semiconductor device such as by way of example a PNP junction transistor comprising the semiconductor body 12 having three electrodes cooperatively associated therewith is utilized to control the application or flow of current in the circuit of the current-consuming device such as the energizing winding of the ignition coil. The source of current is. shown inthe form of electric storagebattery 13 having its negative terminal grounded as at 14 and its positive terminal connected by a suitable switch and conductor 15 to the emitter electrode 16 of the transistor 10. The collector electrode 17 of the transistor is connected by lead 18 to a terminal of a ballast or main current-controlling resistor R3 and hence to the terminal 19 of the primary Winding 20 of the ignition coil. The other end or terminal'21 of the primary wind-f ing is grounded as-at 23 and, in turn, is interconnected with one end of the secondary winding 25. The other" end of the secondary winding 25 is connected by high tension lead 26 to the distributor rotor 27 adapted to contact in timed relation the stationary distributor contacts 28 and thereby apply the firing voltage of the secondary winding to each of the spark plugs 30.

According to the principles of the present invention, the transistor performs the function of on or off means for establishing and interrupting the flow of current required for the energization of the primary winding 20 of the ignition coil from the source of current 13. This function is accomplished by the use of a control circuit for applying the proper polarity voltage bias which is periodically interrupted by the make and break contact mechanism of the conventional ignition system.

In Fig. I, the circuit controlling the transistor switching function comprises a lead 32 connecting the lead 15 to one end of resistor R1 whose other end is connected by leads 34 and 35 to the breaker arm 36 of the conventional distributor carrying the movable contact 37 cooperating with stationary contact 33 grounded as at 39. The breaker arm 36 and its movable contact 37 is actuated in timed relation with the engine by means of a cam 40 mechanically interconnected with the distributor rotor 27 by suitable means shown in dotted lines for providing synchronization between the interruption of the transistor-controlled circuit and the high tension distributor rotor 27.

The base electrode 42 of the transistor 10 is connected by suitable leads to resistor R2, in turn, connected to leads 34 of the control circuit, completing thereby. the

circuit of the transistor and its interconnection with the control circuit for the change in the application of voltages to the transistor electrodes.

the source of potential or terminals of the storage battery 13 as the circuit comprises the resistor R1 and themake and

break contacts

37 and 38 which function in timed relation with the engine by means of the cam 40, whereby the signal source is controlled by the opening and closing of the

contacts

37 and 38. Thus when the

contacts

37 and 38 are opened, the emitter and base electrodes of the transistor, through their direct interconnection, are at the same potential and, therefore, the flow current through the transistor is effectively interrupted, causing the interruption of the fiow of the ignition coil energizing current to the primary winding 20 of the ignition system. The closing or engagement of the

contacts

37 and 38 place the base electrode at a negative potentialwith respect to the emitter electrode of the transistor, and thereby allows the flow of ignition coil R1 should have a comparatively high ohmic resistance value, so that the current handled by the

breaker contacts

37 and 38 has been of very low amplitude. It should be found in practice that a 100,000 ohms resistor can effectively perform the functions of resistor R1 of the transistor control circuit serially connected with the conhas been found in practice that a 40 ohms resistor can effectively perform the functions of resistor R2 in the circuituof the base electrode 42 of the transistor 10. It can'be' seen, therefore, that the'maximum current interrupted by the

contacts

37 and 38 in this form of the invention is lessthan 1 ampere and, therefore, the condenser usually connected across the make and break contact in conventional ignition systems may be dispensed with, without in any way, interfering with the effective operation of the contacts, or causing a decrease in their useful life.

In order to control the amplitude of the energizing current in the input or main circuit of the ignition system, whichincludes the transistor rectifying

electrodes

16 and 17 connected in series with the primary winding 20 of the ignition coil, current-limiting and heat-dissipating resistor R3 is preferably interposed. In this form of the invention, a 1.0 ohm resistor can effectively perform the functions of resistor R3 in the energizing input circuit of the ignitionsystem disclosed. Thus it can be seen that the low tension or input circuit of the ignition system includes, from the non-grounded terminal of the source of energy or storagev battery 13, the lead 15 connected to the emitter electrode 16, the body 12 of the transistor 10, hence tothe collector electrode 17, which is connected by lead 18 to resistor R3, in turn, connected by suitable leads to terminal 19 of the primary winding of the ignition coil 26 grounded as at 23constituting a common path or return for the flow of current to the grounded terminal 14 of the storage battery 13.

An important feature of the present invention resides in the provision of an ignition coil wherein its main components are constructed and arranged in such a manner that the characteristics, which we have found render anv ignition coil highly adaptable for its use with a transistor, are predominantly present, providing an ignition coil wherein itsc ore, the characteristics of its primary Winding, as well as turn ratio with the secondary winding, clearly differ fromconventional ignition coils now used for the same applied voltage as well hereinafter appear.

In the embodiment illustrated in Fig. I, the core 43 of the ignition coilzprovides asubstantially. closed magnetic.-

path and may take an oblong configuration having an air gap of very small width to minimize flux leakage and contribute to materially decrease the primary induced or kick-back voltage. It has been found very effective to make the core 43 of high permeability electrical steel or magnetically soft materials capable of carrying a very high magnetic flux per unit of cross-sectional area, and that a core produced of grain-oriented, high-percentage silicon steel serves the purpose very successfully. The core 43 is preferably formed of a multi-turn winding of a ribbon of grain-oriented high silicon steel coated to separate and hold in position its turns and fashioned to accommodate the primary and

secondary windings

20 and 25 of the ignition coil providing an air gap 45 of extremely small width. We have found that the air gap 45 in the magnetizable circuit ranging between 0.005 to 0.30 serves the purpose very effectively, and that very efficient performance is secured with the air gap in the magnetic circuit of 0.010". In order to insure proper separation and maintain apart the surfaces of the core forming the air gap 45, a properly dimensioned thin plate 47- of non-magnetizable material is inserted therein, thus producing, in effect, a laminated, high permeability, low loss core 43 having a substantially closed magnetic path, whereby magnetic flux leakage, as well as the primary induced voltage, is substantially decreased.

The primary and secondary windings of the ignition coil of the invention are arranged in concentric relation and positioned surrounding the air gap 45 of the substantiallyclosed magnetic core 43. It is contemplated that the ignition coil includes a primary winding to be made for high input energizing current having relatively low inductance and utilizing comparatively few turns with a very high turn ratio between its primary and secondary windings.

In applying the principles of the invention to a 12-volt ignition system for use with conventional spark plugs of' the high voltage discharge or jump spark type, we have found that ignition coils provided with primary windings adapted to be energized by a current ranging from 8 to 12 amperes and having an inductance not higher than 3 millihenries and utilizing less than 50 turns with a turn ratio with respect to the secondary winding of at least higher than 250 to 1 serves the purpose very effectively. Comparative tests indicate that a very efficient performance is obtained when the primary winding of the ignition coil has an inductance from 1 to 2 millihenries and an energizing current of 9 to 10 amperes with 35 turns, while its secondary winding has approximately 18,000 to 19,000 turns, both windings mounted in close proximity to the core of the invention in concentric relation and with the primary winding adjacent to the core and being surrounded by the secondary winding. However, this relationship can be reversed without materially interfering with the successful performance of the system.

In order to provide a comparison of the coil of the present invention and its differentiating features from conventional coils, it should be noted that coils now in use for the same rate of voltage comprise a primary winding having an inductance which rangesfrom 6 to 9 millihenries and an energization current of about 3 to 4 amperes with a turn ratio of lessthan 160 to 1 between the primary and secondary windings.

Fig. II shows another form of the electrical system of the invention, in which a transistor, preferably of the P-N-P class, comprising the semi-conductor body 12 having three conventional electrodes, is used as switch circuit control means for the primary of a step-up transformer which, by its secondary, provides the potential required for firing the spark plugs. A suitable electric source, such as a DC. generator 13', is preferably used for the periodic energization of the transformer and for the periodic application of the proper potential bias for controlling the transistor as a switch or the energizing currenton or off means. The positive terrninal of the generator 13' is connected through a switch and conductor 15 to the terminal 19 of the primary winding 20. The terminal 21 of the primary is connected to the main current-controlling resistance R3, which is connected by lead 18' to the emitter 16 of the transistor 10. The

collector 17 of the transistor 10' is grounded as at 23,

providing the return connection to the negative terminal of the generator 13, which is grounded as at 14'. The terminal 21' of the primary winding 20' is also connected to the secondary winding 25 which has its other end connected by lead 26' to the distributor rotor 27' adapted to successively distribute the secondary voltage through stationary contacts 28' to each of the grounded spark plugs 30'.

The control to secure the periodic energizing current on or off switching function of the transistor 10 is obtained through a control circuit utilizing the same electric current source, such as the generator 13, which provides the energization for the main circuit of the current-consuming device or step-up ignition transformer. This control circuit is secured by interconnecting the emitter electrode 16 with the base electrode 42' through the high resistance unit R1 and the current-limiting resistor R2, and, by having such interconnection, in turn connected by a common lead 35' to the primary circuit, make and break mechanism used in conventional ignition systems.

The make and break or switch mechanism forming a component of the control means for the transistor 10', as shown in Fig. II, comprises the arm 36' carrying the breaker contact 37' movable by the cam 40' for periodic disengagement with the statutory contact 38 grounded as at 39'. The cam 40' is mechanically connected with the distributor rotor 27' by suitable means shown in dotted lines for the synchronization between the interruption of the control circuit of the transistor and the distribution to the spark plugs 30' of the secondary voltage. In this embodiment of the invention the control of the circuit of the transistor 10' provided by the interconnection of the emitter 17' and base electrode 42 forms, in

effect, two parallel paths including the make and breakcontacts 37'38' across the source of current 13'. One of the parallel paths is external of the transistor comprising the conductor 32, high resistance unit R1, conductor 34, common lead 35', and make and break contacts 37'-'38 and ground 39'. The other parallel path includes the emitter 16', semi-conductor body 12', base electrode 42, current-limiting resistor R2, common connector 35, contacts 37-38, and ground 39'. It should be noted that when the contacts 37-38 are closed, the base electrode 42' is placed at a negative potential with respect to the emitter 16' and, therefore, forward current can flow in the emitter to the base. When this condition occurs, current flows from the emitter 16' to the collector 17 to cause the energization of the primary winding 20' I connected in series therewith. However, when the switching contacts 3738 are opened, the base 42 is placed at the same voltage potential as the emitter 16, rendering the transistor 10' non-conductive, thereby cutting off the current in the primary winding 20' and causing the collapse of the magnetic flux resulting in inducing in the secondary winding the voltage required for producing the igniting discharge at the firing gap of the spark plugs 30'.

It has been found, by tests, that a 100,000 ohm resistor can effectively perform the functions of the resistance R1 of the transistor control circuit and that a 15 ohm resistor can effectively perform the functions of the base currentlimiting resistor element R2. Furthermore, that resistors ranging from 15 to 40 ohm resistance produce satisfactory results at base electrode current-limiting resistance. Moreover, that in this form of the invention a .2 ohm resistance may perform the functions of the wattage-dissipating ballast resistor R3 used in the input or main circuit of the system.

It is contemplated that in the form of the embodiment illustrated in Fig. 11 the step-up transformer or ignition aoeecrsr 7. coil should have substantially the same characteristics present in the ignition coil used with the form shown in Fig. I. In the form shown in Fig. II, the magnetizable core 43' preferably takes an oblong configuration formed by two U-shaped sections facing each other and separated by air gaps 45 of very small width to minimize magnetic flux leakage. The core 43' is preferably formed of'a multiturn winding of a ribbon of grain-oriented high silicon steel coated to separate and hold in position its turns and the two U-shaped sections suitably retained to accommodate the primary winding 20' and secondary winding 25 of the ignition coil providing air gaps 45' and eachof its respective legs. We have found that the air gaps in the magnetizable circuit having an overall widthranging between 0.005 inch to 0.30 inch serves the purpose very effectively. In order to insure proper separation and maintain apart the U-shaped core sections, thin plates of non-magnetizable material 47' are inserted therein, producing, in effect, a laminated, high permeability, lowloss core 43, having a substantially closed magnetic path wherein magnetic flux leakage is practically eliminated, so that the induced voltage in the input or primary winding of the transformer is substantially decreased.

The primary and secondary windings of the step-up transformer in the embodiment shown in Fig. II are arranged in concentric relation and have substantially the same characteristics disclosed in connection with the embodiment shown in Fig. I, particularly with respect to its number of turns, its inductance, primary or input current, and the turn ratio between the number of its turns with respect to the number of turns in the secondary winding. Moreover, in this form of the invention it is contemplated that the secondary winding should be mounted in close proximity to the core surrounded by the secondary winding. However, this relationship can be reversed without materially interfering with the successful performance of. the electrical system disclosed in this form of the invention.

In Fig. III there is shown a schematic wiring diagram of another form of the invention in which a transistor 50, preferably of the junction type, which may be of the N-P-N class comprising the semi-conductor body 52 having three conventional electrodes, such as energizing current on or off the emitter 53, collector 54, and base 56 cooperatively associated therewith, is used as switching means to periodically control the energization of the primary winding of an ignition coil utilized for producing the electrical potential required for firing the gaps of the spark plugs. In this form of the invention, a suitable source of direct current, such as a storage battery 57, is used for the energization of the primary winding, as well as for the application of the proper voltage bias for the control circuit of the transistor 50. As shown, the negative terminal of the battery is connected by lead 58 to ground 59. The positive terminal of the battery is connected by a suitable controlling device or switch and conductor 60 to one end or terminal 61 of the primary winding 62. The other end or terminal of the primary winding 62 is connected by conductor 63 to the ballast or'main current-controiling resistance R3, which, in turn, is connected by lead 64 to the collector electrode 54 of the transistor. The emitter electrode 53 of the transistor 50 is connected by conductor 65 to ground as at 67. Thus it can be seen that the primary winding 62, resistor R3, collector 54 and emitter electrodes 53 of the transistor 50 are connected in series and form the main circuit of the ignition system. In this form of the invention, the terminal 61 of the primary winding 62 is also connected to one end of the secondary winding 69 which has its other end connected by high tension lead 70 to the distributor rotor 71 adapted to contact, in timed relation, the stationary contacts 72, and thereby apply the voltage induced in the secondary winding to each of the spark plugs 73.

Following the'principles of the invention, the junction N- Pr-N transistor 50. functions as: the means to: peri- 8. odically interrupt the energization of the primary winding 62 of the ignition coil from the storage battery 57 and thus, by the collapse of the magnetic flux, produces the voltage required for firing the spark plugs 73. The energizing current on or off switching function of the transistor in this form of the invention is accomplished by periodically applying proper voltage bias to render the transistor conductive or non-conductive by a control circuit including the make and break contact mechanism of the conventional ignition system which periodically opens and closes the control circuit.

The control circuit for the transistor 50 is provided by interconnecting the emitter electrode 53 with the base electrode 56 through conductor 68, high resistance unit R1, lead 74, and current-limiting resistor R2 and, in turn, interconnecting both resistances by a common connector 75 to the make and break mechanism of the conventional ignition system which, in this form of the invention, is connected by conductor 76 to the positive or non-grounded terminal of the storage battery 57. As shown in Fig. III, the make and break mechanism forming a component of the control means for the transistor 50 finds counterpart in the circuit make and break contacts used in conventional ignition systems.

The make and break mechanism shown in Fig. III comprises a pivoted breaker arm carrying the movable contact 77 for periodic engagement or disengagement with the stationary contact 78 by the multiple lobed cam 80. The cam 80 is connected to the distributor rotor 71 by suitable means shown in dotted lines for obtaining the synchronization between the interruption of the control circuit of the transistor 50 and the distribution to the spark plugs 73 of the secondary voltage of the ignition coil. In this form of the invention the control circuit for the transistor 50 forms, in effect, two parallel paths, both including the circuit opening and closing contacts 777S across the storage battery 57. One of the parallel paths comprises from the positive terminal of the battery, the conductor 76, the make and break contacts 7778,

conductors

75 and 74, high resistance R1 and conductor 68, which is grounded at 67. The other parallel path comprises from the positive terminal of the battery the conductor 76, make and break contacts 7778, common connecting lead 75, resistor R2, base electrode 56, and semi-conductor body 52 and emitter 53, which is grounded by conoductor 65 as at 67. It should be noted that in this form of the invention, when the contacts 77-78 are closed, that is, in engagement, the base electrode 56 is placed at a positive potential with respect to the emitter electrode 53 and forward current can flow from the base to the emitter electrode which, in turn, permits collector current to flow. The collector electrode 54 is, in effect, at a positive potential with respect to the base, and the emitter, and so it is forward biased, rendering the transistor 50 conductive, and thereby energizing the primary winding 62 of the ignition coil connected in series therewith. However, when the make and break contacts 77-78 are opened, the base electrode is placed at the same potential of the emitter and has, in effect, a zero voltage bias, whereby the emitter and hence the collector current is cut off, interrupting its flow to the primary winding 62. The interruption of the current in the primary winding causes a voltage to be induced in the secondary winding, thereby producing the voltage required for the firing gaps of the spark plugs 73.

In the form of the invention shown in Fig. III, the ignition coil has'substantially the same characteristics present in the ignition coil used in connection with the embodiment disclosed in Fig. 1. Thus the coil comprises a magnetizable core 82 of oblong configuration having an air gap of very small width 33 in order to minimize magnetic flux leakageand decrease the induced voltage in the primary winding. The core 82 is preferably formed of a multi-turn winding formedby a ribbon or strip of grain-oriented high percentage silicon steel suitably coab ed to separate and hold in position its turns and fashioned to accommodate the primary and

secondary windings

62 and 69 respectively. In order to secure the proper separation and maintain apart the aligned surfaces of the core forming the air gap 83, a properly dimensioned spacer 84 of non-magnetizable material is inserted therein. This arrangement produces, in effect, a laminated, high permeability, low loss, magnetizable core 82, having a substantially closed magnetic path, wherein magnetic flux leakage is minimized and the induced voltage in the primary winding is substantially decreased.

The primary and secondary windings of the coil in this form of the invention are arranged in concentric relation and positioned surrounding the air gap 33 of the substantially closed magnetic core 82. It is contemplated that the windings of the ignition coil should have substantially the same characteristics disclosed in connection with the embodiment of the invention shown in Fig. I, particularly with respect to the number of turns in its primary, its inductance, the primary energizing current, as well as the turn ratio between the primary and secondary windings. In this form of the invention the primary winding is mounted in close proximity to the core surrounded by the secondary winding. However, this relationship may be reversed without materially interfering with the successful performance of the system of the invention disclosed in Fig. III.

Fig. IV shows a schematic wiring diagram of another form of the invention in which atransistor of the junction type, which may be of the P-N-P class, comprising the semi-conductor body 86 having three conventional electrodes, such as the emitter 87, collector 89, and base 90 cooperatively associated therewith is used as the energizing current on or off switching means to control the energization of the primary winding of the ignition coil utilized for producing the potential required for firing the gaps of the spark plugs. In this form of the invention, a storage battery 91 is used for the energization of the primary winding, as well as for the application of the voltage bias for controlling the energizing current on or olf switching function of the transistor. The positive terminal of the battery 91 is connected by a suitable controlling device or switch 92 and by a conductor 93 to the emitter electrode 87. The collector electrode 89 is connected by lead 94 to a terminal of the ballast or main current-controlling resistor R3 and hence to terminal 95 of the primary winding 96 of the ignition coil. The other end or terminal 97 of the primary winding is grounded as at 98 and, in turn, is interconnected with one end of the secondary winding 100. The other end of the secondary winding 100 is connected by high tension lead 102 to distributor rotor 103 adapted to contact in timed relation the stationary distributor contacts 104 and thereby apply the votlage of the secondary winding to each of the spark plugs 105.

The control circuit of the transistor in this form of the invention is obtained through the utilization of the same current source which provides the current for the current-consuming device, such as the primary winding 96 of the ignition coil. This control circuit is provided by interconnecting the emitter electrode 87 with the base electrode 90 through conductor 107, high resistance unit R1, and lead 108 connected with the terminal of the current-limiting resistor R2 having its other terminal con nected to the base 90. This interconnection is, in turn, connected by means of a common connector 109 to a circuit make and break mechanism 110 grounded as at 112. The circuit make and break mechanism, diagrammatically shown in Fig. IV as 110, used for the transistor controlling voltage bias means may be of the conventional or any suitable type that will provide sync ronization with the proper firing of the spark plugs. However, it is contemplated that the circuit make and break mechanism should be of magnetic nature such as shown in US. Patent No.- 2,071,573 of February 23, .1937, or

10 may incorporate a light-sensitive arrangement disclosed in US. Patent No. 2,084,267 of June 15, 1937 acting as substitutes for the conventional circuit make and break devices used in present ignition systems.

It is preferred that the signition coil used in the system shown in Fig. IV should have substantially the same characteristics as the one disclosed in connection with the embodiment shown in Fig. I. Thus, the ignition coil comprises a magnetizable core of an oblong configuration having on an air gap of very small width 116 consistent with minimum magnetic flux leakage and one which serves to decrease the induced voltage in the primary winding 96. The core 115 is preferably formed of a multi-turn winding of a flat strip of grain-oriented high percentage silicon steel suitably coated to separate and hold in position its turns and fashioned to accommodate in proper position the primary and

secondary windings

96 and 100. In order to maintain apart the spaced surfaces of the core forming the air gap 116, a suitable dimensioned spacer 117 of non-magnetizable material is inserted therein. This arrangement produces a laminated, highpermeability, low loss, magnetizable core 115 having a substantially closed magnetic path wherein magnetic flux leakage is minimized and the induced voltage in the primary winding is substantially decreased. In the form of the invention shown in Fig. IV, the primary and secondary windings of the ignition coil have substantially the same characteristics as those disclosed in connection with the embodiment of the invention shown in Fig. I.

It is to be understood that the above detailed description of the present invention is intended to disclose an embodiment thereof to those skilled in the art, but that the invention is not to be construed as limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of being practiced and carried out in various ways without departing from the spirit of the invention. The language used in the specification relating to the operation and function of the elements ofthe invention is employed for purposes of description and not of limitation, and it is not intended to limit the scope of the following claims beyond the requirements of the prior art.

What is claimed is:

1. An electrical system comprising a source of supply of unidirectional electric current, a current-consuming device, a transistor comprising a semiconductor body having emitter collector and base electrodes, a main circuit connected across said source comprising in a series connection the emitter and collector electrodes of said transistor with said current-consuming device for controlling in said main circuit the flow of current by said transistor, a second circuit in which are permanently interconnected the emitter and base electrodes of said transistor, and switch means connected to said second circuit operable for connecting and disconnecting said second circuitto said source of supply of unidirectional electric current without disturbing the connections of said emitter and base electrodes.

2. An electrical system comprising a direct electric current supply as a source of current, a current-consuming device, a high resistance unit, a transistor comprising a semiconductor body having emitter collector and base electrodes, conducting means forming a main circuit connected across said source of direct electric current in which are included in a series connection the emitter and collector electrodes of said transistor with said currentconsuming device for controlling the flow of current in said main circuit by said transistor, a second circuit inwhich the emitter and base electrodes are permanently interconnected through said high resistance unit, andswitch means operable for connecting said second circuit across said source of direct electric current to establish the flow of current in said main circuit by said transistor.

3. In combination a source of unidirectional electric current having a pair of terminals, a current-consuming device, a transistor comprising a semiconductor body having emitter collector and base electrodes, current conducting means forming a main circuit in which are connected in series the emitter and collector electrodes of said transistor and said current consuming device across the terminals of said source of current, a branch circuit permanently interconnecting the emitter and base electrodes of said transistor as energizing current on or off switching means for establishing an interrupting in said main circuit the flow of current, and switch means forming a component of said branch circuit for placing said branch circuit across the terminals of said source of unidirectional electric current for establishing in said main circuit the flow of energizing current through said transistor.

4. In combination a source of direct electric current having a pair of terminals, a current-consuming device, a transistor comprising a semiconductor body having emitter collector and base electrodes, current conducting means forming a main circuit connected across the terminals of said source of direct electric current in which are included in series connection the emitter and collector electrodes of said transistor with said current consuming device, a branch circuit connected across the terminals of said source of direct electric current in which are permanently connected the emitter and base electrodes of said transistor operable for establishing an interrupting in said main circuit the flow of energizing current, and switch means forming a component of said branch circuit for disconnecting a terminal of said branch circuit from one of the terminals of said source of direct electric current to cause the interruption in said main circuit of the flow of energizing current by said transistor.

5. An ignition system for multi-cylinder internal com bustion engines subjected to variable operating conditions of load and speed comprising a single source of supply of unidirectional electric current having a pair of terminals, a transistor, an ignition coil having its primary and secondary windings mounted on a core having a substantially closed magnetic path, a main circuit connecting the said primary winding and said transistor in series across the terminals of said single source of unidirectional electric current, a control circuit connected across the said pair of terminals of said single source of unidirectional electric current for causing the operation of said transistor as energizing current on or off switching means for establishing and interrupting the flow of current to said primary winding, and make and break contacts operable in timed relation with the engine forming a component of said control circuit for periodically disconnecting said control circuit from said source causing the said transistor to function as energizing current off switching means for interrupting the flow of energizing current in the main circuit.

6. An ignition system for multi-cylinder internal combustion engines subjected to variable operating conditions of load and speed comprising a resistance, a single source of unidirectional electric current having a pair of terminals, a transistor, an ignition coil having a substantially closed magnetic core of grain-oriented silicon steel, primary and secondary windings mounted on said core, a main circuit connecting said primary winding and said transistor in series across the said pair of terminals of said source of current, a control circuit connected across the pair of terminals of said single unidirectional electric current source interconnecting permanently one of the rectifying electrodes with said resistance and the ohmic electrode of said transistor for causing the operation of said transistor as energizing current on or off switching means for establishing and interrupting the flow of current to said primary winding, and make and break contacts operable in timedrelation with the engine forming a component of said control circuit to periodically disconnect said control circuit across said source for causing said transistor to operate as energizing current off switching means in the main circuit.

7. An ignition system for multi-cylinder internal combustion engines subjected to variable operating conditions of load and speed comprising a single source of supply of unidirectional electric current, a transistor, an ignition coil having a magnetizable core of high permeability grain-oriented material, the primary and secondary windings having a turn ratio higher than 250 to 1 and being arranged in concentric relation directly mounted on said core, the primary winding of said ignition coil having a relatively low inductance and a low primary kick-back voltage, main circuit connections for the fiow of the energizing electrical current from said source of current to the primary winding of said ignition coil through said transistor, a control circuit for causing the operation of said transistor as on or off energizing current switching means for said main circuit connections, and means operable in timed relation with the engine for connecting or disconnecting said control circuit to said single source of supply of unidirectional electric current to cause by said transistor the periodic application or interruption of the flow of the energizing current to the primary winding of said ignition coil.

8. A high voltage ignition system for internal combustion engines comprising a single source of supply of direct electric current, a transistor having emitter collector and base electrodes, an ignition coil having a substantially closed core of grain-oriented silicon steel for its primary and secondary windings, the primary winding of said ignition coil having a relatively low inductance not higher than three millihenries and a low primary kick-back voltage, a main circuit connecting the said primary winding and transistor in series for the flow of the energizing elecrical current from said source of direct electric current to the primary winding of said ignition coil through the emitter and collector electrodes of said transistor, a control circuit in which are permanently interconnected the emitter and base electrodes of said transistor adapted to be connected across said single source of direct electric current for causing the operation of said transistor as on or off energizing current switching means for said main circuit, and switching means forming a component of said control circuit, said switching means operable in timed relation with the engine for connecting or disconnecting said control circuit across said single source of direct electric current to cause by said transistor the periodic application or interruption of the flow of the energizing current to the primary winding of said ignition coil.

9. A high voltage ignition system for variable speed combustion engines comprising a single source of unidirectional electric current, a transistor, an ignition coil having its windings mounted on a core having a substantially closed magnetic path, a high turn ratio between the primary and secondary windings at least higher than 250 to l, the primary winding of said ignition coil having comparatively low inductance not higher than the three millihenries, a main circuit for the flow of energizing current from said single unidirectional electric current source to the primary winding of said ignition coil through said transistor, and a control circuit including means functioning in timed relation with the engine or connecting and disconnecting said control circuit to said single source'ot unidirectional electric current to cause the energizing current on or off function of said transistor thereby controlling the energizing current of the primary winding of said ignition coil.

References Cited in the file of this patent UNITED STATES PATENTS 1,725,053 Brown et al. Aug. 20, 1929 2,203,579 Randolph June 4, 1940 2,392,066 Sargeant Jan. 1, 1 946 2,774,888 Trousdale Dec. 18, 1956 2,809,239 Nielsen Oct. 8, 1957 UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent 209667615 December 27, 1966* Earl W. Meyer, Jr et all,

It is hereby certifiedthat error ent requiring correction and that th corrected below.

Column 1, line 40 for "Qbjetcionable" read appears in the above numbered pate said Letters Patent should read as objectionable line 46, for "0" read of column 4, line 70, for "itsc ore" read its core line 72:}, ior "well" read will column 7, lines 43 and 44, strike out "energizing current on or ME" and insert the same after "used as" in line .15, same column 7; column 8, line 46, 1'01! "conoduotor" read conductor column 9, line 54L for "votlage" read voltage column 10, line 5, for "signition" reed ignition column ll, line l7 after "of" insert supply of line 23, after "in" insert Signed and sealed this 13th day of June 1961, (SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents