US3926165A

US3926165A - Multiple spark discharge system

Info

Publication number: US3926165A
Application number: US440996A
Authority: US
Inventors: James Walter Merrick
Original assignee: Autotronic Controls Corp
Current assignee: Autotronic Controls Corp
Priority date: 1974-02-11
Filing date: 1974-02-11
Publication date: 1975-12-16
Anticipated expiration: 1992-12-16

Abstract

A multiple spark discharge ignition system having a high energy capacitative discharge ignition current which provides multiple striking at the spark gap of a combustion chamber. The timing of the firing can be retarded relative to the power stroke. The duration of the time interval during which the strikes occur is also controlled. In its preferred form, the present invention utilizes the ignition points of an internal combustion engine for its timing signal and the distributor for distributing the high voltage current to the spark gap associated with each of the combustion chambers.

Description

United States Patent Merrick Dec. 16, 1975 4] MULTIPLE SPARK DISCHARGE SYSTEM 3,593,696 7/1971 Guido 123/148 E l 3,599,616 8/1971 Oishi et al. 123/148 CC [75] Inventor iames Walter Memck El Paso, 3,820,520 6/1974 Canup 1. 123/148 E [73] Assignee: Autotronic Controls Corporation, El Primary E-Ydt711'nIChaY1S Myhr Paso, Tex. Assistant E.\'aminerJoseph Cangelosi Filed: Feb. 1974 Attorney, Agent, or Fzrm-Marcus L. Bates [21] Appl. No.: 440,996 [57] ABSTRACT A multiple spark discharge ignition system having a [52] US. Cl 123/148 E; 123/148 OC high n gy p itative i charge ignition rrent [51] Int. Cl. F02? l/OO ich provides multiple striking at the spark gap of a [58] Field of Search 123/148 E, 148 0C m tion h mber. The timing of the firing an e retarded relative to the power stroke. The duration of [56] References Cited the time interval during which the strikes occur is also UNITED STATES PATENTS Controlled 2,811,672 10/1957 c1166" 123/148 oc In its Preferred form the W invention utilizes the 2,898,392 8/1959 Jaeschke 123 143 E ignition points of an internal combustion engine for its 2,940,014 6/1960 Legeay et al 123/148 E timing signal and the distributor for distributing the 0,809 0/19 ssler 123/ 1 8 E high voltage current to the spark gap associated with 3,394,690 7/1968 B611 123/148 E each of the ombustion hambers 3,407,795 10/1968 Aiken et a1 123/148 E 3,489,129 1/1970 155161 et a1. 123/148 oc 4 Cl ims, 14 Drawing Figures US. Patent De c.16,1975 Sheet10f6 3,926,165

Sheet 3 of 6 3,926,165

Patent Dec. 16, 1975 US. Patent Dec. 16, 1975 Sheet40f6 3,926,165

T=90 vs ENGINE. I

FIG.8 T

I/ T 46 g I .Q-0-

A SCR SCR G K DRIVE AMP US. Patent Dec. 16,1975 Sheet6of6 3,926,165

FIG. l2

MULTIPLE SPARK DISCHARGE SYSTEM BACKGROUND OF THE INVENTION tion system. It is known that an internal combustion engine often fails to have the gaseous mixture in all of the combustion chambers thereof exploded on the power stroke, and accordingly, this causes a significant increase in objectionable emissions in the exhaust gases. Moreover, as the objectionable emissions increase, the efficiency of the power plant decreases, thereby causing increased cost of operation.

Complete combustion of the mixture of air and fuel contained in the combustion chamber of an internal combustion engine is seemingly unattainable because of scavenging and cylinder pressures, and moreover is undesirable because of the materials of construction necessarily incorporated into the fabrication of the engine components; however, complete burning of the gaseous mixture to a predetermined resultant reactant product is attainable where proper and sustained ignition of the combustion mixture is effected, and where the flame velocity is of a magnitude to cause propagation of the flame to extend throughout the combustion chamber so that an optimum reaction occurs thereby realizing maximum work from the expansion of the gases.

It is therefore desirable to lower the objectionable emissions from the exhaust gases of internal combus tion engines while at the same time increasing the power output and economy of operation thereof. Moreover, it is prepared to attain these desirable attributes at a minimum of cost and in a simple and uncomplicated manner so that this desirable expedient can be enjoyed by anyone who operates a motor vehicle.

SUMMARY OF THE INVENTION This invention relates to multiple spark discharge apparatus for delivering current to the spark plug of a combustion chamber of an internal combustion engine. The time of firing as well as the duration of the discharge is electronically controlled to thereby enhance the efficiency of combustion.

The apparatus in its preferred form includes a multiple spark discharge control circuit connected to deliver multiple strikes across the spark plug when energized by a proper timing signal. A converter changes low voltage DC to high voltage DC and is connected to the multiple spark discharge control circuitry.

The firing duration and timing retard control circuit is connected to the multiple spark discharge circuitry so that the duration and timing of firing can be controlled for each power stroke of a cylinder.

Accordingly, a primary object of the present invention is the provision of a multiple spark discharge apparatus for delivering multiple strikes across a spark gap of a combustion chamber of an internal combustion engine to thereby cause ignition of the combustable mixture contained within the combustion chamber to occur in a more efficient manner.

Another object of the invention is to provide improvements in multi-strike ignition systems for use in providing ignition within a combustion chamber.

A further object of this invention is to disclose and provide improvements in multi-strike ignition systems which has incorporated therewith means by which the duration of the strikes can be controlled.

A still further object of this invention is to provide a multi-strike ignition system having means by which the time of the strikes can be controlled relative to the power stroke of the engine.

Another and still further object is to provide improvements in multiple strike discharge circuitry which enables a greater number of strikes to occur within a finite time interval.

These and various other objects and advantages 0 the invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims and by referring to the accom panying drawings.

The above objects are attained in accordance with the present invention by the provision of a combination of elements which are fabricated in a manner substantially as described in the above abstract and summary.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a multi-strike discharge apparatus made in accordance with the present invention;

FIG. 2 discloses several curves illustrating the wave form of a conventional ignition system contrasted with the wave form of a multi-strike ignition system as might be viewed by observing the wave form of the current at the spark plug of an internal combustion engine;

FIG. 3 is a diagrammatical, part schematical illustration of circuitry arranged in accordance with the teachings of this invention;

FIG. 4 discloses several different wave forms produced by various ones of the circuitry of FIG. 3;

FIGS. 5 and 6 disclose a schematical representation of circuitry for carrying out one form of the present invention;

FIG. 7 is a schematical representation of another form of part of the circuitry disclosed in the foregoing figures;

FIG. 8 discloses a series of curves which sets forth the wave form observed at various locations within the circuitry of FIG. 7;

FIGS. 9 and 11 set forth another form of part of the circuitry disclosed in the foregoing figures;

FIG. 10 sets forth curves depicting the wave form produced at various locations within the circuitry of FIG. 9; and,

FIGS. 12 14 disclose a number of curves which enable a theoretical discussion of the merits of the present invention to be more precisely considered.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 there is disclosed one form of the present invention indicated by the arrow at numeral 10. A mounting plate 11 enables the main body portion 12 to be affixed in close proximity to an internal combustion engine. Circuitry is housed within the main body while heat radiating fins l3 dissipate heat therefrom. The apparatus of the present invention can be connected into the ignition system of a conventional engine by utilizing the electrical connections or terminals 14 20 as will be discussed in greater detail later on in this disclosure.

In FIG. 2, the upper curve discloses a wave form of the voltage in a conventional ignition system, while the lower curve illustrates the wave form of the voltage which is attained by utilizing the teachings of the present invention. In each curve, the breakdown voltage V,, is required to initiate a spark across the plug gap, while V,- is the ionizing voltage which is also the voltage measured across a gap after current flow has been initiated.

In FIG. 3 there is diagrammatically illustrated an electronics ignition system made in accordance with the present invention. The circuitry is connected to a low voltage source of current at l4, l6 and produces a high voltage current at of a particular wave form. The circuitry is comprised of an engine timing signal conditioning circuit A having the input thereof connected to a timing signal at 17, which for purposes of this embodiment is illustrated as being in the form of a conventional set of ignition points 21. The conditioned timing signal provides a signal for the input of the engine timing control circuit B, which can be remotely controlled at 18 so as to selectively retard the timing of the ignition, as may be desired.

The output of the timing control provides a signal for the firing duration control circuitry C. The last named circuitry has a remote duration control 19 for controlling the duration of the firing portion of the ignition cycle.

A converter D converts the low voltage DC supply into high voltage DC to thereby provide the multi-spark discharge control circuitry E with a high voltage supply. The firing duration control circuitry output causes the circuitry E to impose high voltage upon the transformer F to thereby provide the distributor 23 with a plurality of high voltage sparks which is transferred to the spark plug 24 of the illustrated internal combustion engine cylinder chamber 25.

In FIG. 4 the various curves A F, respectively, represent the preferred input signal to each of the circuits, A F, respectively, of FIG. 3. Looking particularly to curve A of FIG. 4, it is seen that the impulses are spaced 90 apart for an eight cylinder engine, and, are of a wave form such as may be obtained with a magnetic pulse triggered distributor. In curve C, each of the impulses have been converted to a square wave of about 01 to 20 in duration, respective to engine crank shaft rotation. The impulses of Curve E is 1 40 in duration. The multiple strikes of the impulse of curve, F is of the same duration and timing as curve E. Hence, it can be seen that the timing signal A is conditioned by circuit A to provide a cleaner signal B which in turn is converted into signal C, with the latter being adjustable in time as noted. The signal E corresponds in duration to that of signal F.

FIGS. Sand 6 jointly represent circuitry for carrying out the present invention, wherein various portions of the circuitry have been isolated by dot-dash lines and provided with letters A F; respectively, which relate to the block diagram A F, respectively, of FIG. 3. As seen in FIG. 5, a terminal block is provided, having connectors 14 20 which can be related to the similar terminal block of FIG. 1.

Those skilled in the art, having digested this entire disclosure, will be able to comprehend the purpose and operation of the circuitry depicted by FIGS. 5 and 6. The circuit values of the various electrical components disclosed in FIGS. 5 and 6 are as follows:

CIRCUIT VALUES OF FIGURES 5 AND 6 R1 .47 ohms R20 4.7K ohms R39 2.2K ohms R2 .47 ohms R21 2K ohms R40 1K ohms R3 047 ohms R22 1K ohms R41 2.2K ohns R4 047 ohms R23 R42 2.2K ohms R5 1K ohms R24 1K ohms R43 15K ohms R6 1K ohms R25 4.7K ohms R44 4.7K ohms R7 220 ohms R26 10K ohms R45 1K ohms R8 47 ohms R27 1K ohms R46 4.7K ohms R9 4.7K ohms R28 68 ohms R47 4.7K ohms RIO 1K ohms R29 10K ohms R48 4.7K ohms R11 1K ohms R30 1K ohms R49 ohms R12 100 ohms R31 R50 100K ohms R13 1K ohms R32 1K ohms R51 10K ohms R14 220 ohms R33 22K ohms R52 4.7K ohns R15 220 ohms R34 10K ohms R53 1K ohms R16 11K ohms R35 4.7K ohms R54 R17 1K ohms R36 1K ohms R55 100 ohms R18 10K ohms R37 22K ohms R56 1K ohms R19 1K ohms R38 1K ohms R55 220 ohms R56 200 ohms Cl 250 yf D1 1N4001 C2 250 D2 1N4001 C3 D3 1N4001 C4 0.03 D4 1N4001 C5 .005 D5 1N4937 C6 .005 D6 1N4937 C7 .01 D7 1N4937 C8 .01 D8 1N4937 C9 35 D9 1N4937 C10 .01 D10 1N4154 C11 4.7 D11 1N4154 C12 2.2 D12 C13 .002 D13 1N5229 C14 .05 D14 1N4154 C15 .01 D15 1N4154 C16 .001 D16 1N4154 C17 .1 D17 1N4154 C18 1.0 D18 1N4154 D19 1N4001 D20 1N400l Q1 T1P36A Q2 T1P36A Q3 T1P36A Q6 2N4355 Q7 T1597 Q8 T1597 Q9 2N6027 Q10 T1597 Q11 T1597 Q12 T1597 Q13 T1597 Q14 T1597 closed a constant and adjustable duty cycle single shot having an input 40 of a wave form disclosed by numeral 40 in FIG. 8. The output 41 of the circuitry of FIG. 7 has a wave form corresponding to the curve indicated by the arrow at numeral 41 of FIG. 8. In FIG. 7, the

junctions

42 and 43, respectively, correspond to the wave forms 42 and 43, respectively, of FIG. 8. It will be noted that the time interval between the impulses of the curves depends upon the number of cylinders and firing cycle of the engine under consideration.

Looking now to the details of FIG. 9, which discloses a simplified embodiment of the discharge circuitry illustrated at E in FIGS. 3, 5, and 6, it will be noted that the high voltage from the converter D of FIG. 3, for example, is connected at junction 50 of FIG. 9, while the output from the control circuitry C of FIG. 3 forms an input at junction 44 for the circuitry of FIG. 9. A high tension ignition transformer T broadly corresponds to transformer F of FIG. 3. The wave form of the current at various locations 44 49 throughout the circuit of FIG. 9 is disclosed by curves 44 49 in FIG. 10.

FIG. 11 shows one form of the invention which broadly corresponds to the circuitry D of FIG. 3. The low voltage DC to high voltage DC converter is comprised of a transformer T-l having the illustrated primary and a tapped secondary N-l, N-2, N-3, connected to transformer windings T-2, having primary windings N4, N5, and secondary windings N-6, N-7. Disconnect 53 is provided for convenience. The output from transformer T-l is connected into the circuitry of FIG. 9 at numeral 50.

FIGS. 12 14 disclose the operational characteristics of the present multi-spark ignition system. In FIG. 12, the amperage 55 is plotted against the voltage 56. The voltage feedback is indicated by curve 57 while curve 58 discloses the wave form obtained with a typical current feedback converter made in accordance with the present invention.

Numerals

60, 62, 64, 66, 68, shows the curve as its amplitude increases to 1 amp and discharges at 300 volts. Curve 57 continues as indicated at 70 or 72.

In FIG. 13 the amperage input 74 is plotted against the output amperage 75. Curve 76 relates to voltage feedback while curve 77 relates to current feedback.

In FIG. 14, capacitor voltage 78 is plotted against time 77. Curve 82 is a plot of a converter made in accordance with the present invention, while curve 84 is the wave form of a voltage feedback converter. The curves commence at 80 and extend along

line

16 and 88, with the design center being indicated by numeral 88. The normal recharge range is measured between 88 and 90. Numeral 92 indicates the excess voltage rise due to converter kickback spikes, and is illustrated as being 40%, with 4 being typical.

OPERATION As indicated in FIG. 3, in conjunction with various other remaining Figures, the present ignition system is comprised of various combinations of functional blocks A E. The input to the engine timing signal conditioning block A can be the conventional breaker points associated with an automotive type engine, or alternatively, can be a magnetic pickup, photocell and window arrangement, or any other signal generating means associated or indexed with the rotating crank shaft of the engine, so long as the signal provides a timed indication of piston position. The function of the timing signal conditioning circuitry is to change the wave form A of FIG. 4 to that seen illustrated by curve B. This expedient provides short negative electrical pulses which are suitable for driving the retard control circuitry B, seen in FIGS. 3 and 6.

The engine timing control circuitry B, seen in FIGS. 3, 6, 7, and 8, is basically a duty cycle controlled single shot that divides the firing interval T between successive firing pulses into two intervals T-l and T-2, the ratio of which is proportional to the ratio of two current sources [-1 and [-2, according to the relationship as follows:

stroke engine By making one or both current sources adjustable, a new timing signal can be generated at the end of T-l, which can be adjusted electronically without readjusting the distributor. This novel expedient makes possible remote control of ignition timing electronically without the requirement of mechanical linkage and the like. One means by which this desirable expedient is carried out is disclosed in the simplified circuitry of FIG. 7, and is shown in detail in FIGS. 5 and 6.

Looking now to the details of the firing duration control circuitry C disclosed in FIGS. 3, 5, and 6, it will be noted that this circuit is essentially the same as the timing control circuit previously discussed in conjunction with FIGS. 7 and 8, except that the circuitry is used to control the firing duration of the multi-spark discharge circuitry E rather than being used to control the relationship of T and T The circuit C is triggered by the timing signal generated by the output of the timing control circuit B. This signal generates a gate signal which controls the firing duration. It may also be controlled electronically and remotely as seen in FIGS. 5 and 6, so as to enable selection of the most optimum engine operating condition.

Looking now to the converter D of FIGS. 3, 5, 6, and 1 1, it will be seen that this circuit converts the 12 volts DC, for example, of the automotive electrical system into the 400 volts DC source needed to charge the energy storage capacitor of the multi-spark discharge circuit. The converter must have the capability of recharging the energy storage capacitor in ample time to obtain the required multiple discharges on each firing stroke of each of the cylinders of the internal combus tion engine, and at the same time, the circuitry must be efficient in order to prevent excessive heating beyond the limits which can be tolerated by the individual components thereof.

Stated again, the simplified circuitry of FIG. 9 is a discharge circuit with various wave forms produced therein being disclosed in FIG. 10, wherein the curve 44 shows the firing duration for each power stroke of one of the pistons of the engine. The curve 45 of FIG. 10 shows a plurality of strikes for each successive cylinder firing, with the individual strikes being characterized by the discharge time TD and time of recharge TR. The sloped portion of the time of recharge relates to the DC/DC converter recharging the discharge capacitor.

Curve 46 illustrates the wave form of the voltage in the high tension ignition transformer primary. Numeral 52 indicates the discharge time TD which is determined by the inductance of the high tension transformer 'and discharge capacitor. Numeral 52' is the recharge time TR of the discharge capacitor.

The firing voltage is seen illustrated by curve 47, wherein V,, is related to the VJT or Q firing voltage, which is approximately equal to the source or battery voltage.

Curve 48 illustrates the VJT bias pulses, while curve 49 illustrates the SCR gate drive pulses.

The multi-spark discharge circuit of FIG. 9 repetitively discharges the illustrated energy storage capacitor into the primary of the high-tension ignition transformer T as fast as the DC/DC converter (FIG. 2!), FIG. D, and FIG. 11) can recharge it during the firing duration gate pulse. In this circuit, the unijunction transistor senses when the energy storage capacitor is charged to an appropriate level, preferably 90% of maximum, as determined by the battery voltage. Those skilled in the art will readily understand the remaining details of the current flow and wave forms in the simpli fied circuit presented in the embodiment of FIGS. 9 and 10, as well as the more specific embodiment of FIGS. 5 and 6.

Looking now to the multi-spark discharge circuitry disclosed in FIGS. 3, 5, 6, and 11, it will be seen that this circuit repetitively discharges the energy storage capacitor into the primary of the high tension ignition transformer as quickly as the converter can recharge the capacitor during the firing duration gate pulse. In this circuit, the unijunction transistor senses a threshold voltage which preferably occurs when the energy storage capacitor is charged to 90% of maximum as determined by the battery voltage.

The present invention provides low dissipation and output current when shorted by the SCR during the discharge pulse, thereby preventing latch-up of the SCR and excessive heating of the converter transistors. The present circuitry also provides a very high output current from 30 to 90% of the output voltage, which enables rapid recharging of the capacitor at the end of each discharge pulse. The converter of the present invention draws minimal current when the discharge capacitor is fully charged between firing sequences, thereby minimizing battery drain and heat buildup.

The advantage of a conventional prior art current feedback converter for ignition systems is its high efficiency while handling light to heavy loads because it employs a base drive which is proportional to the load, therefore, its output voltage does not rise appreciably at light loads. However, these prior art systems suffer the disadvantage of an excessive heat dissipation and output current during output short on the discharge pulse, thereby causing possible SCR latchup and destruction of the converter transistors, which renders conventional current feedback concepts unsuitable for reliable ignition systems.

The use of a conventional prior art voltage feedback converter is advantageous in a capacitor discharge electronic ignition circuitry because of the simplicity of the circuit and beacuse it can be designed for low dissipation and current drain when the output is shorted during the discharge pulse. However, the disadvantages for such a system is its poor efficiency at light loads due to the high base drive to the transistors and because of the required base current limiting resistors. Moreover, the output current drops linearly with the decreasing output voltage thereby requiring more time to recharge the discharge capacitor. Furthermore, high peak collector currents at light loads cause high energy spikes of voltage to occur at the collector of the transistors and output, thereby causing the output voltage to rise above the design center which results in excessive voltage stress on various circuit components, especially at light loads between the firing sequences.

The converter of the present invention enjoys all the advantages of the voltage feedback and current feedback systems and avoids all of the foregoing undesirable attributes. This desirable expedient is accomplished in accordance with the present invention by the provision of circuitry fabricated in a manner exemplified by the present embodiments.

As seen in the hypothetical curves presented in FIGS. 12 14, when the output voltage is of a value between the

numerals

59 and 60, the converter works as a voltage feedback inverter with very little drive thereby minimizing the occurrence of stall current during each discharge pulse of ignition. Temperature compensated forward bias is provided by the resistors Rl-4 and the diodes 5 and 6 of FIG. 1 l, for example. This increased forward drop of the diodes at cold temperature compensates for the increased base drive required by Ql-Q4 at cold temperature. Positive current feedback occurs through T-2, the current feedback transformer, but is shunted away from the transistor bases by the presence of diodes D-1 and D-2 whenever the output falls below numeral 60. Whenever the output goes above the value indicated by numeral 62 of FIG. 12, there is sufficient voltage across the voltage feedback windings N-l and N-2 to prevent the current feedback from being shunted away from the transistor bases, and therefore, above numeral 62 the converter works in the current feedback mode. The current feedback passes from windings N6 and N7, through D-3 and D-4, and through the current balancing resistors R-S, R-S to the transistor bases between the points indicated by

numerals

64 and 66. Therefore, essentially constant current is available along line 64 to recharge the discharge capacitor. The available current above the value indicated by numeral 66 quickly drops to zero thereby preventing excessive voltage stress of the circuit components between the firing sequences. Above point 66 a slight amount of voltage feedback is provided to stabilize the circuitry through means of R1 and R-4, which stabilize the converter when there is no low current to provide current feedback. In normal operation, there is sufficient energy kickback from the high tension ignition transformer to recharge the discharge capacitor above point 62, thereby allowing rapid recharge along the time interval 64 between

numerals

62 and 66.

The output is at zero during the actual discharge pulse which is a low current and dissipation point for the converter. A comparison of the recharge time of the converter of FIGS. 5 and 6, for example, with a conventional voltage feedback converter is shown in FIG. 14. Those skilled in the art will now appreciate the novel and heretofore unknown advantages of the present invention over the prior art forms of ignition systerns.

I claim:

1. In an internal combustion engine having a combustion chamber within which an ignition spark is to be provided with the spark occuring in timed sequence respective to engine rotation, said engine having means providing a timing signal, a DC current source, and a distributor connected to deliver high voltage current for the spark; the improvement comprising:

a multiple spark discharge apparatus for delivering current to the distributor in response to said timing signal; said discharge apparatus including means forming a multiple spark discharge control circuit connected to deliver multiple strikes for said spark when said circuit is energized;

means, including circuitry, forming a DC/DC converter for increasing the voltage of said DC current source, and connected to supply current to said multiple spark discharge control circuit;

a firing duration control circuit means connected to said multiple spark discharge control circuit for controlling the duration of firing each time said timing signal is received;

an engine timing control circuit means for changing the time of firing respective to engine rotation; said engine timing control circuit means divides the firing interval between successive firing pulses into first and second intervals, means by which the ratio of said first and second intervals is made proportional to a first and second current source, and means for adjusting one said current source to thereby provide an adjustable ignition timing sig' nal;

an engine timing signal conditioning circuit means connected to said engine timing control circuit for conditioning the timing signal, to thereby provide a signal for driving said engine timing control circuit;

so that a spark of multi-strikes is provided for initiating combustion each stroke of the internal combustion engine with the duration and time of the multistrikes being controlled.

2. The multiple spark discharge apparatus of claim 1 wherein said firing duration control circuit means includes a duty cycle controlled single shot that divides the firing interval between successive firing pulses into first and second intervals, circuit means by which the ratio of said first and second intervals is made proportional to a first and second current source, means for adjusting one said current source to thereby provide an adjustable firing duration control signal.

3. In an internal combustion engine having a combustion chamber within which an ignition spark is to be provided with the spark occuring in timed sequence respective to engine rotation, said engine having means providing a timing signal, a DC current source, and a distributor connected to deliver high voltage current for the spark; the improvement comprising:

a multiple spark discharge apparatus for delivering current to the distributor in response to said timing signal;

said discharge apparatus including means forming a multiple spark discharge control circuit connected to deliver multiple strikes for said spark when said circuit is energized;

means, including circuitry, forming a DC/DC converter for increasing the voltage of said DC current source, and connected to supply current to said multiple spark discharge control circuit; a discharge capacitor connected to be charged by said DC/DC converter; circuit means including a hightension coil connected to provide said spark, said circuit means being connected to cause said dis charge capacitor to discharge into said high-tension coil when the capacitor has been substantially charged;

an engine timing control circuit means for changing the time of firing respective to engine rotation;

an engine timing signal conditioning circuit means connected to said engine timing control circuit for conditioning the timing signal, to thereby provide a signal for driving said engine timing control circuit; so that a spark of multi-strikes is provided for initiating combustion for each power stroke of the inter- 5 nal combustion engine, with the duration and time of the strike being controlled.

4. The multiple spark discharge apparatus of claim 3 wherein said firing duration control circuit means includes a duty cycle controlled single shot that divides the firing interval between successive firing pulses into first and second intervals, circuit means by which the ratio of said first and second intervals is made proportional to a first and second current source, means for adjusting one said current source to thereby enable the timing signal to be adjusted.

5. In combination with an internal combustion engine having a source of DC current, and a spark gap connected to ignite a combustible mixture contained within a combustion chamber thereof in timed relationship to the power stroke, means generating a timing signal in timed relationship to the power stroke of the engine; a multi-spark discharge system;

said system including means forming an engine timing control circuit, a low voltage to high voltage DC converter circuit, and a multi-spark discharge control circuit; circuit means connecting said DC converter circuit to provide a source of power for said discharge control circuit;

said engine timing control circuit includes means that divides the firing interval between successive firing pulses into first and second intervals, means by which the ratio of said first and second intervals is made proportional to a first and second current source, and means for adjusting one said current source to thereby provide an adjustable timing signal;

circuit means connecting said timing signal to said engine timing control circuit for producing an output signal in timed relationship respective of said timing signal, circuit means by which the timed relationship between said timing signal and said output signal can be remotely controlled;

circuit means connecting said output signal to said discharge control circuit for causing said discharge control circuit to supply said spark gap with hightension current during the time interval of said output signal.

6. The combination of claim 5 wherein said circuit means connecting said timing signal to said enging timing control includes a signal conditioning circuit means for changing the timing signal into a signal having a wave form of only spaced pulses with a pulse occuring for each of the timing signals.

7. In combination with an internal combustion engine having a source of DC current, and a spark gap connected to ignite a combustible mixture contained within a combustion chamber thereof in timed relationship to the power stroke, and means generating a timing signal in timed relationship to the power stroke of 60 the engine; a multi-spark discharge system;

said system including means forming an engine timing control circuit, a low voltage to high voltage DC converter circuit, and a multi-spark discharge control circuit; circuit means connected to said DC converter circuit to provide a source of power for said discharge control circuit;

a firing duration control circuit means connected between said engine timing control circuit and said multi-spark discharge control circuit for controlling the duration of the output of the last said circuit; said firing duration control circuit means di vides the firing interval between successive firing pulses into first and second intervals, and further includes means by which the ratio of said first and second intervals is made proportional to a first and second current source, and means for adjusting one said current source to thereby provide an adjustable timing signal;

8. In combination with an internal combustion engine having a source of DC current, and a spark gap connected to ignite a combustible mixture contained within a combustion chamber thereof in timed relationship to the power stroke, and means generating a timing signal in timed relationship to the power stroke of the engine; a multi-spark discharge system;

said system including means forming an engine timing control circuit, a low voltage to high voltage DC converter circuit, and a multi-spark discharge control circuit; circuit means connecting to said DC converter circuit to provide a source of power for said discharge control circuit;

said multiple spark discharge control circuit includes a discharge capacitor connected to be charged by said DC converter, a high-tension coil connected to the spark gap; circuit means, including a unijunction transistor, connected to cause said discharge capacitor to discharge into said high-tension coil when said transistor senses that the capacitor has been substantially charged;

9. The combination of claim 8 wherein said circuit means connecting said timing signal to said engine timing control includes a signal conditioning circuit means for changing the timing signal into a signal having a wave form of only spaced pulses with a pulse occuring for each of the timing signals.

10. Method of producing multiple spark discharges for the spark gap of an internal combustion engine having a combustion chamber comprising the steps of:

.l. producing a timing signal representative of each time combustion should occur in a combustion chamber of the internal combustion engine;

2. adjusting the duration of the timing signal to a value representative of the time in which the multi- LII ple sparks are to occur within the combustion chamber;

3. connecting a source of high-tension current to the spark gap and causing said high-tension current to flow across the spark gap each time said source is energized, said high-tension current having a frequency which imposes a multiplicity of sparks across the spark gap during the time interval of the duration of the timing signal;

4. energizing said source of high-tension current each time said timing signal is produced;

5. converting the timing signal of step (1) into a first and second electrical signal which represent first and second time intervals and which jointly represent the firing interval between successive firing pulses;

6. electrically making the ratio between said first and second intervals proportional to a first and second current source;

7. adjusting one said current source to thereby change the timing signal duration.

11. The method of claim 10, and further including the step of adjusting the duration of the timing signal electrically so as to enable the engine timing to be remotely controlled.

12. The method of claim 10 wherein said hi-tension current is obtained according to the following steps:

5. connecting a discharge capacitor to a hi-tension ignition coil and charging and discharging the capacitor at a rate to attain the frequency recited in p 6. carrying out step (5) for the duration of the timing signal so that a plurality of sparks occur across the spark gap each time ignition occurs in the combustion chamber.

13. Method of producing multiple spark discharges for the spark gap of an internal combustion engine having a combustion chamber comprising the steps of:

l. producing a timing signal representative of each time combustion should occur in a combustion chamber of the internal combustion engine;

2. adjusting the duration of the timing signal to a value representative of the time in which the multiple sparks are to occur within the combustion chamber;

5. connecting a discharge capacitor to a high-tension ignition coil and charging and discharging the capacitor at a rate to attain the frequency recited in step (3);

6. carrying out step (5) for the duration of the timing signal so that a plurality of sparks occur across the spark gap each time ignition occurs in the combustion chamber.

14. In an internal combustion engine having a combustion chamber within which an ignition spark is to be provided with the spark occuring in timed sequence respective to engine rotation, said engine having means providing a timing signal, a DC current source, and a 13 distributor connected to deliver high voltage current for the spark; the improvement comprising:

means, including circuitry, forming a DC/DC con-- verter for increasing the voltage of said DC current source, and connected to supply current to said multiple spark discharge control circuit;

said firing duration control circuit means includes a duty cycle controlled single shot that divides the firing interval between successive firing pulses into first and second intervals, circuit means by which the ratio of said first and second intervals is made proportional to a first and second current source, means for adjusting one said current source to thereby provide an adjustable firing duration control signal;

an engine timing control circuit means for changing the time of firing respective to engine rotation; an engine timing signal conditioning circuit means connected to said engine timing control circuit for conditioning the timing signal, to thereby provide a signal for driving said engine timing control circuit;

so that a spark of multistrikes is provided for initiating combustion with the duration and time of the strike being controlled.

Claims

1. In an internal combustion engine having a combustion chamber within which an ignition spark is to be provided with the spark occuring in timed sequence respective to engine rotation, said engine having means providing a timing signal, a DC current source, and a distributor connected to deliver high voltage current for the spark; the improvement comprising: a multiple spark discharge apparatus for delivering current to the distributor in response to said timing signal; said discharge apparatus including means forming a multiple spark discharge control circuit connected to deliver multiple strikes for said spark when said circuit is energized; means, including circuitry, forming a DC/DC converter for increasing the voltage of said DC current source, and connected to supply current to said multiple spark discharge control circuit; a firing duration control circuit means connected to said multiple spark discharge control circuit for controlling the duration of firing each time said timing signal is received; an engine timing control circuit means for changing the time of firing respective to engine rotation; said engine timing control circuit means divides the firing interval between successive firing pulses into first and second intervals, means by which the ratio of said first and second intervals is made proportional to a first and second current source, and means for adjusting one said current source to thereby provide an adjustable ignition timing signal; an engine timing signal conditioning circuit means connected to said engine timing control circuit for conditioning the timing signal, to thereby provide a signal for driving said engine timing control circuit; so that a spark of multi-strikes is provided for initiating combustion each stroke of the internal combustion engine with the duration and time of the multi-strikes being controlled.

3. In an internal combustion engine having a combustion chamber within which an ignition spark is to be provided with the spark occuring in timed sequence respective to engine rotation, said engine having means providing a timing signal, a DC current source, and a distributor connected to deliver high voltage current for the spark; the improvement comprising: a multiple spark discharge apparatus for delivering current to the distributor in response to said timing signal; said discharge apparatus including means forming a multiple spark discharge control circuit connected to deliver multiple strikes for said spark when said circuit is energized; means, including circuitry, forming a DC/DC converter for increasing the voltage of said DC current source, and connected to supply current to said multiple spark discharge control circuit; a discharge capacitor connected to be charged by said DC/DC converter; circuit means including a high-tension coil connected to provide said spark, said circuit means being connected to cause said discharge capacitor to discharge into said high-tension coil when the capacitor has been substantially charged; a firing duration control circuit means connected to said multiple spark discharge control circuit for controlling the duration of firing each time said timing signal is received; an engine timing control circuit means for changing the time of firing respective to engine rotation; an engine timing signal conditioning circuit means connected to said engine timing control circuit for conditioning the timing signal, to thereby provide a signal for driving said engine timing control circuit; so that a spark of multi-strikes is provided for initiating combustion for each power stroke of the internal combustion engine, with the duration and time of the strike being controlled.

5. connecting a discharge capacitor to a hi-tension ignition coil and charging and discharging the capacitor at a rate to attain the frequency recited in step (3);

5. In combination with an internal combustion engine having a source of DC current, and a spark gap connected to ignite a combustible mixture contained within a combustion chamber thereof in timed relationship to the power stroke, means generating a timing signal in timed relationship to the power stroke of the engine; a multi-spark discharge system; said system including means forming an engine timing control circuit, a low voltage to high voltage DC converter circuit, and a multi-spark discharge control circuit; circuit means connecting said DC converter circuit to provide a source of power for said discharge control circuit; said engine timing control circuit includes means that divides the firing interval between successive firing pulses into first and second intervals, means by which the ratio of said first and second intervals is made proportional to a first and second current source, and means for adjusting one said current source to thereby provide an adjustable timing signal; circuit means connecting said timing signal to said engine timing control circuit for producing an output signal in timed relationship respective of said timing signal, circuit means by which the timed relationship between said timing signal and said output signal can be remotely controlled; circuit means connecting said output signal to said discharge control circuit for causing said discharge control circuit to supply said spark gap with high-tension current during the time interval of said output signal.

7. In combination with an internal combustion engine having a source of DC current, and a spark gap connected to ignite a combustible mixture contained within a combustion chamber thereof in timed relationship to the power stroke, and means generating a timing signal in timed relationship to the power stroke of the engine; a multi-spark discharge system; said system including means forming an engine timing control circuit, a low voltage to high voltage DC converter circuit, and a multi-spark discharge control circuit; circuit means connected to said DC converter circuit to provide a source of power for said discharge control circuit; a firing duration control circuit means connected between said engine timing control circuit and said multi-spark discharge control circuit for controlling the duration of the output of the last said circuit; said firing duration control circuit means divides the firing interval between successive firing pulses into first and second intervals, and further includes means by which the ratio of said first and second intervals is made proportional to a first and second current source, and means for adjusting one said current source to thereby provide an adjustable timing signal; circuit means connecting said timing signal to said engine timing control circuit for producing an output signal in timed relationship respective of said timing signal, circuit means by which the timed relationship between said timing signal and said output signal can be remotely controlled; circuit means connecting said output signal to said discharge control circuit for causing said discharge control circuit to supply said spark gap with high-tension current during the time interval of said output signal.

8. In combination with an internal combustion engine having a source of DC current, and a spark gap connected to ignite a combustIble mixture contained within a combustion chamber thereof in timed relationship to the power stroke, and means generating a timing signal in timed relationship to the power stroke of the engine; a multi-spark discharge system; said system including means forming an engine timing control circuit, a low voltage to high voltage DC converter circuit, and a multi-spark discharge control circuit; circuit means connecting to said DC converter circuit to provide a source of power for said discharge control circuit; said multiple spark discharge control circuit includes a discharge capacitor connected to be charged by said DC converter, a high-tension coil connected to the spark gap; circuit means, including a unijunction transistor, connected to cause said discharge capacitor to discharge into said high-tension coil when said transistor senses that the capacitor has been substantially charged; circuit means connecting said timing signal to said engine timing control circuit for producing an output signal in timed relationship respective of said timing signal, circuit means by which the timed relationship between said timing signal and said output signal can be remotely controlled; circuit means connecting said output signal to said discharge control circuit for causing said discharge control circuit to supply said spark gap with high-tension current during the time interval of said output signal.

14. In an internal combustion engine having a combustion chamber within which an ignition spark is to be provided with the spark occuring in timed sequence respective to engine rotation, said engine having means providing a timing signal, a DC current source, and a distributor connected to deliver high voltage current for the spark; the improvement comprising: a multiple spark discharge apparatus for delivering current to the distributor in response to said timing signal; said discharge apparatus including means forming a multiple spark discharge control circuit connected to deliver multiple strikes for said spark when said circuit is energized; means, including circuitry, forming a DC/DC converter for increasing the voltage of said DC current source, and connected to supply current to said multiple spark discharge control circuit; a firing duration control circuit means connected to said multiple spark discharge control circuit for controlling the duration of firing each time said timing signal is received; said firing duration control circuit means includes a duty cycle controlled single shot that divides the firing interval between successive firing pulses into first and second intervals, circuit means by which the ratio of said first and second intervals is made proportional to a first and second current source, means for adjusting one said current source to thereby provide an adjustable firing duration control signal; an engine timing control circuit means for changing the time of firing respective to engine rotation; an engine timing signal conditioning circuit means connected to said engine timing control circuit for conditioning the timing signal, to thereby provide a signal for driving said engine timing control circuit; so that a spark of multi-strikes is provided for initiating combustion with the duration and time of the strike being controlled.