PULSE ACTIVATED IGNITION SYSTEM

Abstract: An ignition system for an engine has a transformer with a primary winding (L1) and a secondary winding (L2). A magnetic pulse timer (20) provides a bipolar signal to the input circuit of a pair of transistors (Qa-Qb, Qn-Qp, Q2-Q3, Q4-Q5, Q6-Q7) of opposite conductivities. The transistor pair is simultaneously activated and deactivated to provide or discontinue current flow in the primary winding and to create an induced voltage in the primary winding. Simplified circuits having single transistors (Q8, Q9) are provided for timer (20, 20a, 30) actuation. Other circuits include transistor pairs (Q10-Q11, Q12-Q13) connected in Darlington manner, and include transistor pairs (Q14-Q15, Q16-Q17) directly coupled to each other and activated by the timer. A high power ignition system utilizing signal type transistors (Q18, Q19) as a bipolar pair drives a power transistor (Q20, Q21) to obtain extremely high voltage and current output, this system having all transistors ON and OFF at substantially the same time. Directly coupled transistor pairs of opposite conductivities (Q22-Q23, Q24-Q25, Q26-Q27, Q28-Q29) are included in ignition circuits wherein a portion of the ignition transient signal is fed back to the input of these transistor pairs to effect increased duty cycles analogous to the duty cycle of an AC fed ignition system. Circuits involving bipolar transistor activation (Q30-Q31) feed a power transistor (Q32) to also effect an increased duty cycle by feedback methods.

Description: PULSE ACTIVATED IGNITION SYSTEM TECHNICAL FIELD This invention is in the field of electronic ignition systems utilizing magnetic pulse timers or breaker point timers. BACKGROUND ART A magnetic pulse timer coupled to a semiconductor is utilized to activate a power transistor that is connected to an ignition transformer primary winding. Such prior art circuitry is usually dependent upon variations in voltage levels of a DC power source and contains excessive components. An ignition circuit with an improved bipolar activated timer is shown in U.S. Patent 4.377.151 to same applicant. The circuit therein likewise makes use of a timer and its bipolar semiconductor circuit to drive a power transistor connected to the ignition transformer primary winding so as to activate and deactivate such power transistor. DISCLOSURE OF INVENTION The invention utilizes a pair of transistors of opposite conductivities with their output circuits serially connected. One transistor collector has DC power applied thereto while the other transistor collector is connected to the primary winding of the ignition transformer. The bases of these transistors are directly coupled to the terminals of the output winding of the timer's coil, providing a bipolar pulse output to these transistors to activate and deactivate such transistors directly and without any intermediate semiconductor stages between such transistors and timer output winding. Such circuit enjoys the benefit of developing appoximately double the voltage induced into the primary winding of the ignition transor er as compared to a single power transistor controlling primary winding current flow. The increased induced primary voltage also approximately doubles the secondary voltage and ignition energy. Included are simplified ignition circuitry, some of the Darlington connected configurations and others of directly coupled transistors of opposite conductivities to operate with either a magnetic pulse timer or a breaker point timer. Also included is an ignition system analogous to the one disclosed in U.S. Patent 4»377*151 but operating on a different principle, namely, all transistors are either ON or OFF at the same time. A variation of the circuitry having transistors of opposite conductivities and utilizing a transient current feedback path provide ignition voltages and currents of lengthened duty cycles, such circuitry using very few components and " being di ensionally very small. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an electrical schematic of a circuit utilizing a Darlington transistor pair in accordance with the invention. FIG. 2 is an electrical schematic of the circuit of FIG. 1 including means for biasing the transistors to reduce the voltage output from the secondary winding of the ignition transformer. FIG. 3 is a circuit similar to that of FIG. 1 except that the primary winding of the ignition transformer is located in a different collector circuit from that illustrated in FIG. 1. FIG. 4 is an electrical schematic showing the circuit ooff FFIIGG.. 1 activating an AC generator. FIGS. 5 and 6 are waveforms of voltages present between 3 the bases of the transistors of FIG. 1 and between the base and 4 emitter of each transistor. 5 c FIGS. 7, 8, 9 and 10 are representative P-N and N-P 6 _ unijunction type Darlington transistors utilized in the o Q circuit of FIG. 11, which is analogous to FIG. 1 circuit, a FIGS. 12, 13, 14 and 1 are representative N-channel 0 and P-channel field effect Darlington transistors utilized ■ ^ in the circuit of FIG. 18, which is the analog of FIG. 1 circuit. 12 FIGS. 16 and 17 are representative of N-channel and ■ - P-channel field effect non-Darlington type transistors utilized 14 in the circuit of FIG. 19 * and performing in manner similar - -- t<- that of FIG. 18 circuit. 16 FIGS. 20, 21 and 22 are schematics of simplified ignition 17 circuits for operation with magnetic pulse or breaker point timers. 18 FIGS. 23. 24 and 25 are schematics bf simple high energy 19 ignition circuitry, eac connected in Darlington configuration. 20 FIGS. 26, 27 and 2 ~ 8 are schematics of ignition circuits 21 having transistors of opposite conductivites connected in tandem. 22 FIGS. 29 and 30 are schematics of high energy ignition 23 systems utilizing a bipolar input to a high power stage, wherein 24 all transistors are ON and OFF at substantially the same time. 25 FIGS. 31, 32, 33, 34, 35, 36, 37, 38, 39 and 40 are 26 schematics of very high energy ignition circuits with 27 extended duty cycle duration. 28 FIGS. 41 and 42 " are schematics of ignition circuits utilizing 29 a bipolar input to a high power stage and with extended duty cycle 30 duration. 31 FIG. 43 represents a drawing of an oscilloscopic trace of 32 a voltage waveform generated by the circuits with extended duty cycles. 33 FIG. 44 represents a drawing of an optical illustration 34 of the base of an igniter firing when energized by the waveform of 35 FIG. 43* BEST MODE FOR CARRYING OUT. THE INVENTION Referring to FIGS. 1, 5 and 6, an ignition system is illustrated utilizing a conventional magnetic pulse timer 20, operating in conjunction with a pair of Darlington type transistors a and b, designated by the symbol D in the transistor illustrations. The output circuits of such transistors of the NPN and PNP types are serially connected by connecting their emitters in series. A DC power source 10, the negative terminal of the power source being at ground potential, has its positive terminal connected to the collector of transistor Qa, the collector of transistor Qb being connected to one side of primary winding L1 of an ignition transformer, the other side of the primary winding and one side of secondary winding L2 being commonly at ground potential, whereas the other side of secondary winding L2 is fed to a rotor member of a high voltage conventional distributor, not shown herein, such distributor being one that feeds four igniters inasmuch as reluctor wheel 25 of timer 20 is designated for a four igniter operation. Such reluctor wheel and distributor rotor are electrically insulated from each other and are mounted on and driven by the same distributor shaft 24- Reluctor wheel 25 therefore has four protrusions 26 regularly spaced from each other at the wheel's outer periphery. Each time one of protrusions 26 passes armature pole piece 22 of a permanently magnetized core 21, a bipolar pair of pulses is generated at outputs A and B of coil 23, coil 23 being wound on core 21• The operation of timer 20 as it relates to the circuits of FIGS. 1, 2, 3, 4, 11, 18 and 19, is provided in detail in U.S. Patent 4,377,151 issued to same applicant, but a summary of such operation is provided herein. When reluctor wheel 25 is at standstill, or when lead A is at negative potential provided by coil 23, lead B will be at positive potential, and no current I will flow. When lead A is at positive potential and B at negative potential, current I will flow in both the base of Qa and the base of Qb turning on both Qa and Qb, energizing primary winding L1 with current supplied by DC power source 10 and charging L1. When waveform F is at the output of the leads A and B, a positive potential pulse is provided at A and a negative potential is exhihibited at B due to rotation of reluctor wheel 25 to cause protrusion 26 to pass pole piece 22, causing Qa and Qb to conduct. Conduction of current through the collector-emitter circuits of Qa and Qb will continue to energize primary winding L1 until the next negative pulse output of the bipolar pulse pair from coil 23 will occur. Such next negative pulse is spaced a substantial distance from its preceding positive going pulse due to spacing between protrusions, thus affording primary winding L1 a sufficient time to develop a large charge and ' thereby enable it to release ' such charge or magnetic flux upon arrival of such next negative pulse to induce a voltage in primary winding L1 for transfer to secondary winding 2 by magnetic coupling between L1 and L2. Waveform F output therefore is characterized by a pair of bipolar pulses closely spaced to each other wherein the negative pulse leads the positive pulse in time frame. On the other hand, waveform G, obtained by transposing leads A .and B, so that lead B is connected to the base of Qa and lead A is connected to the base of Qb, will provide a leading positive pulse of the bipolar pulse pair output of coil 23« Circuits requiring the charging of an inductor to obtain an induced voltage therein on discharge action require waveform F condition. Circuits requiring switching of power generated by an AC generator, such as shown in FIG. 4, require waveform G condition, and hence leads A and B are connected accordingly. Hence, it can be appreciated that one pulse of the bipolar pulse pair will be obtained when the leading edge of protrusion 26 passes the leading edge of pole piece 22, and the other pulse of such pair will be obtained when the lagging edge of protrusion 26 passes the lagging edge of pole piece 22. With respect to any of the configurations illustrated, . an advantage is gained utilizing the circuits of Qa and Qb in that trigger actuation of such circuits by generation of either waveform F or ff as input to Qa and Qb makes switching initiation independent of the DC power source 10 and consequently independent of its voltage and current variations. The benefit of bipolar operation by activating and deactivating Qa and Qb simultaneously may be appreciated by examining their emitter-base voltages V--, illustrated as waveforms H and J in FIG. 6. During conduction of Qa the base to emitter voltage 7— will drop from a positive voltage level to zero level, whereas the base to emitter voltage 7 ™ of Qb will rise from a negative voltage level to zero level, thereby resulting in a base to base voltage which is double the base to emitter voltage of either Qa or Qb alone. Qa and Qb will simultaneously switch from their OFF to their ON states to permit charging of primary L1 rapidly. Discharge of charged primary L1 will occur when the next negative pulse of the bipolar pulse pair is applied at lead A, causing lead B to be of positive polarity and simultaneously causing current I to go to zero level, turning off Qa and Qb simultaneously. Although Qa and Qb have been illustrated as Darlington type multifunction transistors, such transistors may be of the power type, may be of the unijunction or field effect Darlington or non-Darlington types. Referring to FIG. 2, the same operational criteria applies as discussed in conjunction with FIG. 1 configuration. A capacitor C is shown shunting secondary winding L2 of the ignition trans ormer. Such capacitor is of the distributed parameter type as illustrated in U.S. Patents 4,41 ,304 or 4,422,054 to same applicant. It had been found that such capacitor increases the voltage and current output of L2 dramatically. In order to decrease such voltage L2 outputs, transistors Qa and Qb may be conveniently biased by utilizing resistors R1 , R2 and/or R3 connected between the emitter and base of one or both Qa and Qb, or by connecting resistor R3 between the bases of Qa and Qb. The following tables indicate test results of the utilization of resistors R1 , R2 and/or R3, wherein transistor Qa was of the TIP 142 Darlington type and transistor Qb was of the TIP 147 Darlington type made by Motorola Semiconductor Products, Inc. Qa BIAS Relative 7oltage R1 Base to Emitter Output Level in ohms Voltage in volts of L2 Infinite -0.16 Maxiii-um 2400 - +0.18 Intermediate 1300 +0.27 Low Qb BIAS Relative Voltage R2 Base to Emitter Output Level in ohms Voltasre in volts of L2 Infinite -0.15 Maximum 2400 , -0.27 Intermediate 1300 -0.27 Low Qa - Qb BIAS Relative Voltage R3 Base to Emitter Base to Emitter Output Level in ohms of Qa in volts of Qb in volts of L2 4600 -0.12 +0.06 Maximum 2300 -0.06 +0.06 Intermediate 1300 -0.01 +0.025 Low Referring to FIG. 3, the circuit therein is the same as the one in FIG. 1 , except that the primary winding L1 is in the collector circuit of transistor Qa and is powered by DC source 10 applying a positive voltage to the junction of winding L1 and L2, and the collector of Qb is at ground potential. Otherwise the operation of this circuit is identical to the operation discussed for FIG..1 configuration. One detriment of this circuit is that one end of secondary winding L2 is connected to DC power source 10 and hence requires a capacitor between the junction of L1 and L2 and ground in order to provide a shortened electrical path for ignition current flow and to prevent ignition energy loss due to long leads connecting source 10 to the ignition transformer. Referring to FIGS. 4 and 5, timer 20 is the same as described in conjunction with FIG. 1 description, except that transistors n and Qp therein may be of non-Darlington transistors, or Darlington ty es if desired. Output leads from the coil of timer 20 are connected to bases qf Qn and Qp respectively. Transistor Qn is of the NPN type and transistor Qp is of the PNP type. Transistor Qri has its collector connected to the positive terminal of DC source 10, the collector of transistor Qp being connected to a center tap at 73 of a tertiary or feedback winding made part of ignition transformer j70. Ignition transformer 70 has a center tapped primary winding 71 , the ends of which are connected to the collectors of a pair of NPN transistors Q1 , their emitters being at ground potential. The center tap of winding 7(1 is connected to the positive terminal of DC source 10. The circuit consisting of windings 7/1 and 73 and transistors Q1 is an alternating current square wave generator of the Royer type providing the AC rectangular waveform each time the center tap at 73 is biased positively for enabling conduction of transistors Q1 , and well known in the art. This generator is triggered by activation of transistors Qn and Qp utilizing waveform G of FIG. ~ principle. Activation' of transistors Qn - Qp causes a positive DC voltage level to be applied to tap 73 turning on transistors Q1 in sequence to create oscillation of the Royer generator circuit. Secondary winding 12. analogous to secondary winding L2 of FIG. 1 , provides the output of the AC generated power to a high voltage distributor. The negative pulse of the bipolar pulse pair arriving at the base of Qn, causes the base of Qp to be positive, turning off Qn and Qp simultaneously and providing ze o bias to tap 73 causing transistors Q1 to be turned o ^ and producing zero voltage across the output of winding 72. T e following listing shows transistors in small type T0-220AB plastic packages usable in the foregoing circuits to enable the total ignition electronics to be manufactured . in a container small enough to be included within the confines. of the ignition distributor per se: NPN Tvne PNP Tvtie Usable As 2N6388 2N6668 Qa, Qb TIP 142 Motorola TIP 147 Motorola Qa, Qb SE 9302 Motorola SE 9402 Motorola Qa, Qb D44H11 D45H11 Qn, Qp 2N6488 2N6491 On, Qp MJE 13007 Motorola MJE 5852 Motorola . Qn, Qp It sho ld be noted that the collector to emitter circuits of transistors Qa and Qb exhibit capacitive output parameters which aid in producing an increased voltage and current in the primary winding L1. Transistors Qn and Qp also have such inherent output capacities, as well as transistors Q2 through Q7 inclusive. Referring to FIGS. 7, 8, 9, 10 and 11, unijunction transistor circuitry of Q2 and Q3 may be utilized with magnetic pulse timer 20 in similar manner as discussed for the FIG. 1 situation. A Darlington P-N type transistor with an N type base Q2 is shown in FIG. 7, and for simplicity in symbolic notation in FIG. 8 with the symbol D therein indicating a Darlington type circuit. Likewise, a unijunction Darlington transistor of the N-P type with a P type base Q3. is shown in FIG. 9 with its symbolic form denoted by symbol D in FIG. 10. Such transistors Q2 and Q3 have their bases B1 series connected, the base B2 of Q2 being connected to DC power source 10, whereas the base B2 of Q3 is connected to primary winding L1 of the ignition transformer. The output winding of the timer is connected to the emitters of 02 and Q3 providing similar inputs to activate and deactivate Q2 and Q3 as discussed for the FIG. 1 situation. * Referring to FIGS. 12, 13, 14,15, 16, 17, 18 and 19, which illustrate bipolar switching operation of an ignition system utilizing timer 20 connected to a Darlington pair of N-channel and P-channel transistors and also to a non- Darlington pair of N-channel and P-channel transistors of the field effect types, when such transistor pairs are utilized as ignition electronics activated and deactivated by the bipolar pulse pair respectively produced by timer 20. Transistor Q4 of FIG. 12 is symbolically shown as a Darlington type in FIG. 13 illustration wherein the symbol D therein indicates Darlington circuitry. Transistor Q4 is of the N-channel type. Transistor Q5 of FIG. 14 is of the P-channel type and is symbolically shown as a Darlington type in FIG. 15 wherein symbol D identifies Darlington circuitry. FIG. 18 illustrates transistors Q4 and Q5 as providing the total ignition electronics in conjunction with timer 20. FIGS. 16 and 17 illustrating N-channel and P-channel non-Darlington transistors are also usable as a pair of complementary transistors of opposite conductivities in the circuit of FIG. 19. Hence, in FIG. 18, the gates of transistors Q4 and Q5 are connected to the output winding or coil in timer 20, and in FIG. 19 the gates of transistors Q6 and Q7 are similarly connected. In both FIGS. 18 and 19 the N-channel transistors Q4 and Q6 have their drains connected to the positive terminal of the DC source 10. The drains of P-channel transistors Q5 and Q7 are connected to the primary winding L1 of the ignition transformer. The sources of transistor pair Q4 - Q5 are serially interconnected and the sources of transistors Q6 - Q7 are also serially interconnected. Otherwise the circuits of FIGS. 18 and 19 both function as described for the circuit of FIG. 1 situation, wherein the gates are analogous to the bases of Qa - Qb, the drains are analogous to the collectors of Qa - Qb, and the sources are analogous to the emitters of Qa - Qb. Referring to FIG. 20, a simplified ignition system is powered by DC source 10 through ignition switch 11 when such switch is closed. Switch 11 is connected to a common junction of primary winding L1 and secondary winding L2 of the ignition transformer. Primary winding L1 is connected to the collector terminal of NPN transistor Q8, which transistor may be of the Darlington type, such as TIP 142, TIP 142T or 2N6388 made by Motorola, Inc., or of the non-Darlington type such as MJE 2801 made by Motorola, Inc. The emitter of Q8 is at ground potential and the base of Q8 is connected to the output end A of sensor output winding 23 of magnetic pulse timer 20 * Timer 20 operates as was described above in connection with FIG. 1 structure. Output end B of winding 23 is at ground potential, and according to the illustration in FIG. 5 » waveform F determines the switching ON and OFF of transistor Q8 in similar manner as described in conjunction with FIG. 1 configuration, wherein the positive excursion of waveform F voltage turns ON Q8 to charge L1 , and the negative excursion thereof turns OFF Q8 to discharge L1 and induce a voltage in L1 for transfer to L2 to feed rotor 41 of distributor 40 which in turn energizes igniters 50 sequentially via stator members 42 of distributor 40. Capacitor 60, not part of. the ignition system, is generally used for noise reduction in an automotive radio receiver, due to radiation from ignition system cables conducting ignition current therein. In this structure, additional components such as capacitors, inductors, resistors, diodes or transistors arenot required. Referring to FIG. 21 , the circuit therein utilizes a PNP type transistor Q9 which may also be of the Darlington type. Darlington transistor types TIP 147, TIP 1 7T or 2N6668 made by Motorola, Inc. or non-Darlington transistor such as MJE 2901 made by Motorola, Inc. may be used as Q9» Except for the change in transistors to opposite conductivities, this configuration operates similarly to that of FIG. 20 configuration. However, here the.operation is dependent on feeding waveform G of FIG. 5 to the base of the transistor, achieved by connecting end B of output sensor winding 23 of timer 20 to the base of the transistor and providing a positive potential to end A of winding 23. In this way, upon receiving a negative pulse portion of waveform G at the base of Q9, Q9 is turned ON and remains in such state to charge L1 until the next-in-sequence positive pulse of waveform G arrives at the base of Q9 turning Q9 OFF to discharge L1 and provide energy to igniters 50 in the same manner as discussed for the FIG. 20 configuration. In this structure, L1 is connected in circuit with the collector of Q9 and the common junction of L1 and L2, such junction being at ground potential. Here too, although capacitor 60, used for. similar purpose as in the FIG. 20 case, is connected between ■ switch 11 and ground, shunting battery 10, this capacitor is not considered part of the ignition system. In this structure, additional components such as capacitors, inductors, resistors, diodes or transistors are not Tequi-red. Referring to FIG. 22, this circuit is the same as the circuit of FIG. 21 , except that it is triggered by timer 30, inasmuch as such circuit is tailored for ignition systems still using contactors to charge and discharge L1. Here timer 30, also driven by engine shaft 24 which drives cam 33, opens and closes contactors 31 and 32 * Contactor 31 is connected to the base of Q9 and. contactor 32 is at ground potential. Resistor 34, part of timer 30, is connected between the base, of Q9 and battery 10 when switch 11 is closed, so that a positive potential is normally provided to the base of Q9, maintaining Q9 in non-conducting state. When a low portion of cam 33 is opposite contactor 32, contactor 3 cooperates with contactor 31 to place the base of Q9 at ground potential creating a current flow through resistor 34 * Such grounded base starts Q9 to conduct, energizing primary winding L1 for the period that contactors 31 and 32 are in cooperation, known as the dwell time. At the end of the dwell time, when a high portion of cam 33 actuates contactor 32 and causes contactors 31 and 32 to cease cooperating, the base of Q9 is again at positive potential turning OFF Q9 and causing L1 to discharge-inducing a voltage in L1. The remainer of the ignition cycle is the same as discussed for FIG. 20 configuration. Here too, no additional resistors, capacitors, inductors, diodes or transistors are required for proper ignition system performance. Referring to FIG. 23, the circuit herein is identical to that of FIG. 20 except that a plural number of NPN transistors, Q10 and Q11 , are used instead of transistor Q8. The circuit actually is a quasi-Darlington circuit since the emitter of Q10 is connected to the base of Q11, but the collectors of Q10 and Q11 are not commonly connected, the collector of Q10 being at positive DC potential and the output circuit consisting of winding L1 , connected between power source 10 and the collector of Q11 when switch 11 is closed, is part of Q11 circuit. T e input circuit is between the base of Q10 and ground. Timer 20 is connected by means of lead A to the base of Q10, lead B being at ground potential. Resistor45 in the Q10 collector circuit limits the-vόltagβ imposed upon the-base of Q11. Transistor Q10 may be of the 2N5618 type, and transistor Q11 may be of the MJE 2801 type made by Motorola, Inc. ~o additional resistors, capacitors, inductors, diodes or transistors are required for proper ignition system performance. Referring to FIG. 24, the circuit herein is the same as described for FIG. 21 configuration, except that a plural number of PNP transistors, Q12 and Q13, are connected in quasi-Darlington manner, the emitter of Q12 being connected to the base of Q13, the collector of Q12 being at ground potential and winding L1 being connected between the collector of Q13 and ground. The input from timer 20 to the base of Q12 and positive DC potential applied to end A of sensor winding 23 of timer 20 is the same as for the connection to Q9 of FIG. 21. Operationally, this circuit is idential to that of FIG. 23« Capacitor 60 is connected in the same manner as in the FIG. 23 case. The transistors may be represented by type 2N581 for Q12 and type MJE 2901 made by Motorola, Inc. for Q13. No additional components such as capacitors, inductors, resistors, diodes or transistors are required for proper system operation. Referring to FIG. 25, the circuit is identical to that of FIG. 24 except that timer 30, as described in conjunction with FIG. 22, is used in a like manner as for FIG. 22 situation. Here, the output of timer 30 is fed to the base of Q1 . The quasi-Darlington interconnection of transistors Q12 and Q13 are as discussed for the FIG. 24 case. Typical PNP transistors are of similar types as for the FIG. 24 case. This circuit is tailored for use with ignition systems still using breaker contactors in their timers. No additional components such as capacitors, inductors, resistors, diodes or transistors, other than illustrated, are required for proper system operation. Referring to FIGS. 20 through 25, capacitor 60, effectively shunting the DC power input to the ignition circuits, may included as part of such circuits if desired. T 15- 1 Referring to FIG. 26, the circuit herein consists of a 2 pseudo Darlington circuit of an NPN transistor coupled to a PNP 3 transistor, triggered by a magnetic pulse timer 20, identical to the •4 one used in the FIG. 20 configuration. Lead A of the pulse sensor 5 winding feeding the base of NPN transistor Q14, the emitter of Q14 6 and lead B of the sensor winding being at ground potential, provide 7 sensor winding waveform F of FIG. 5, so that the positive pulse of 8 the waveform will turn Q14 to its ON state. The collector of Q14 9 is directly coupled to the base of PNP transistor Q15, the emitter 10 of Q15 being coupled to direct current source 10 when switch 11 11 is closed, and the collector of Q15 is connected to one side of 12 primary winding L1 , the other side of primary L1 being at a 13 common junction with one side of secondary winding L2 of the 14 ignition transformer and at ground potential. A distributed 15 parameter capacitor C, as heretofore referred to, may be connected 16 in parallel with secondary winding L2 for increasing the energy 17 output from the transformer, and fed to rotor 41 of distributor 40, 18 sequentially energizing igniters 50 as heretofore described in 19 conjunction with FIG. 20 configuration. Capacitor 60 may be 20 connected so as to effectively shunt source 10 and provide a 21 reduced AC ohmic resistance path for ignition current flow in 22 primary winding L1. The advantage of this circuit with opposite 23 conductivity transistors is that the base current of Q15 is 24 identical to the collector current of Q14, and this pair of 25 transistors provides a high input impedance to the timer's 26 sensor winding inductance, and thus a high waveform voltage 27 amplitude to the base of Q14 of the bipolar pulse pair voltage 28 generated by timer 20, for reliable triggering of transistor Q14 29 and consequently the triggering of Q15« 30 Typical transistors for Q14 may be either type 2N3773 31 or MJE 2801 by Motorola, Inc. Typical transistors for Q15 32 may be either type 2N6609 or MJE 2901 by Motorola, Inc. Referring to FIG. 27, the circuit herein employs a pseudo Darlington circuit consisting of a PNP transistor Q16 as its input transistor, the collector of which feeds the base of NPN transistor Q17. Resistor 16 in the emitter of Q16 produces- a voltage drop from the voltage of power source 10, a reduced voltage being applied to the base of transistor Q17« Winding L1 is in the collector circuit of Q17» such winding and the emitter of Q16 being at positive DC potential when switch ' 11 is closed, and maintaining Q16 in its OFF state. On application of waveform G of FIG. 5 to lead A, the negative pulse of the bipolar pulse pair overcomes the positive DC bias at the base of Q16, places such base at a negative potential and turns Q16 to its ON state, applying a positive potential to the base of Q17 and turning Q17 to its ON state, causing collector current flow in Q17 and charging L1 with power from source 10. When the next-in-sequence positive pulse of the bipolar pair arrives at the base of Q16, both Q16 and Q17 will be switched OFF and L1 discharged to induce a high voltage in L2 for sequentially energizing the engine's igniters via distributor 40 as described in conjunction with FIG. 20 configuration. It should be noted that except for interchange of transistors, this circuit is functionally the same as that described for the FIG. 26 case. Capacitors C and/or 60 may be used here as in the ca.ce of FIG. 26 configuration. Referring to FIG. 28, this structure is identical in all respects to that of FIG. 27 configuration, and only the timer is different. Timer 30, feeding transistor 16, is of the breaker-point contactor type -which is fully described in conjunction with FIG. 22 configuration. All other components such as capacitor 60 connected to one side of primary winding L1 and capacitor C shunting secondary winding L2, may be utilized. Referring to FIGS. 27 and 28, typical transistors for Q16 may be either type 2N6609 of MJE 2901 by Motorola, Inc. Typical transistors for Q1 may be either type 2N3773 or MJE 2801 by Motorola, Inc. Referring to FIG. 29, an extremely high power ignition system having high voltage and current output fed to a distributor as shown in FIG. 20, is provided with the bipolar magnetic pulse circuit consisting of transistors Q18 and Q19 of opposite conductivities, analogous to the bipolar pair Qa-Qb used for FIG. 1 configuration, and such circuit functions in a similar manner to that described for the FIG. 1 condition. However, here Q18 and Q19 may be of the signal type, for reasons stated below and to effect economy of fabrication. Transistor pair Q18 and Q19 may also be of the Darlington type, the multi unction type, the unijunction type or the field effect type as illustrated in FIGS. 1-4 and 7-19. Magnetic pulse timer 20 triggers and activates bipolar pair Q18 and Q19, as in the case of FIG. 1, however here waveform G as illustrated in FIG. 5, with the positive pulse of the bipolar pulse pair output of winding 23 of the timer 20 leading the negative pulse of such pulse pair, appears to provide better performance than with one of waveform F, the transposition of leads A and B. Thus with lead B connected to the base of Q18 and lead A connected to the base of Q19, waveform G will be provided to activate Q18-Q19 pair in a similar manner discussed in conjunction with FIG. 1 configuration. Typical transistors for Q18 are types 2N3019, 2N2222, MPS-U10 or MJE 200 by Motorola, Inc. Typical transistors for Q19 are types 2N2905, 2N2907, MPS-U60.or MJE 210 by Motorola, Inc. It should be carefully noted that power transistor Q20 is of opposite conductivity to that of Q18, the base of Q20 being directly coupled to the collector of Q18. Consequently, the base current I of Q20 is identical to the collector currents of Q18 and Q19, since all transistors are powered by direct current source 10 fed to the emitter of Q20, and direct current flow from the emitter to base of Q20 proceeds to flow through the collector- emitter circuits of Q18 and Q19 to ground. The bipolar pair are switched on at the time the positive pulse of waveform G at lead B turns on Q18 and the negative potential at lead A at that same time turns on 0.19 so that all three transistors are conducting at the same time, to provide a current through primary winding L1 charging L1 with current from source 10. This circuit is different in principle from the one in U.S. Patent 4,377,151 , and quite unique in that all transistors are turned on and .off at substatially the same time, the power transistor is of opposite conductivity to the transistor of the bipolar pair to which it is coupled, no resistors are required in this circuit, and that the power transistor Q20 is actually triggered by a pulse having both positive and negative excursions, as was observed in a laborator test utilizing an., oscilloscope connected between the base of Q20 and ground. The DC current I was measured at 130 milliamperes. The voltage induced in primary winding L1 was measured at approximately 1000 volts, peak-to-peak, so that for a 100:1 ratio ignition transformer, the voltage across secondary winding L2 and fed to the igniters would be about 100 kilovolts peak-to-peak. The igniter current was difficult to measure but there was sufficient evidence that such current was in excess of one ampere. During discharge of primary winding L1 , not only is a high voltage induced in L1 , but a high collector to base voltage would appear and destroy transistors Q18 and Q19, were it not for another unique feature inherent in this system, which involves all transistors remaining effectively in their on states during the charge and discharge cycles of L1 , acting as self- protective devices due to the very low terminal impedances of transistors in their on states, that is collector-emitter, emitter-base and collector-base terminals. This is achieved by the inherent nature of transistors in that there is a time delay in the transistors actually turning off after actual timer switch- off action. Since the waveform output is very short during L1 discharge, it can be accommodated in the delay time period, so that in effect the high voltage produced by L1 cannot burn out any of the transistors due to their effective terminal short circuit or very low impedances. Such inherent characteristic permits the use of inexpensive transistors for Q18 and Q1 while a the same time providing pin point ignition energy waveform to the igniters. In this circuit Q20 could be of the MJE 4353, • TIP 147, TIP 147T or MJH 11021 by Motorola, Inc., and may be of a suitable Darlington type, multi unction type, unijunction type or field effect type as illustrated in FIGS. 1-4 and 7—19- A distributed parameter capacitor C, referred to in conjunction with FIG. 2, shunting winding L2 may β utilized. ' Capacitor 60, utilized for reducing the ohmic AC return path and also for radio noise reduction, is not a part of this ignition circuit and is generally part of the automotive engine wiring system. This capacitor usage is referred to in conjunction with FIG. 20 configuration. Referring to FIG. 0, the principles involved are identical to those of FIG. 29 configuration. Here, the power transistor Q21 is of the NPN type, the collector thereof being coupled to primary winding L1. Direct current power is fed to both the collector of Q18, and the collector of Q21 through L1. Here, the base current I of Q21 is also the collector current of Q18 and Q19, all transistors turning on and off substantially at the same time and otherwise perfoiming identically to FIG. 29 configuration. Typical transistors for Q21 are MJE 4343, MJE 13009, MJH 11022, TIP 142, TIP 142T by Motorola, Inc. However, Q21 may be a suitable Darlington type, multi unction type, unijunction type or field effect type, as illustrated in FIGS. 1-4 and 7-19- Referring to FIGS. 31 , 43 and 44, the structure herein is the same as illustrated in FIG. 26, except that in FIG. 31 a feedback path consisting of capacitor 80 is provided between primary winding L1 and terminal B of sensor coil 23 to produce a portion of the ignition transient signal developed at the primary L1 and to be fed back to the input of NPN transistor Q22. Such feedback of signal current increases the time duration of the ignition energy duty cycle from about 5 to about 25$ as illustrated in FIG. 43* FIG. 43 is a drawing at 90 of two ignition firing cycles 91 and 92 wherein the duty cycle obtained by FIG. 31 structure is the ratio of 93 to 94 time units, 93 being the time period when ignition current is flowing and 94 being the total ignition cycle wherein ignition current flows only 25 of the time. Such duty cycles can be increased to anywhere in the order of 50 by variation in values of capacitor 80. Typical capacitor variations may be from 0.01 to 0.5 microfarads, and such capacitors may be of low voltage ratings. This illustration in FIG. 43 shows a duty cycle of 25$ obtained with capacitor 80 being 0.05 microfarads. FIG. 44 illustrates the firing arc by an electrical igniter 100 coupled to the ignition transformer secondary winding L2, wherein the igniter has a conductive base 101 and an axial electrode 102, and a plurality of ignition arcs at 103 are generated by the ignition occurring according to FIG. 43 illustration. Since resistor 81 and capacitor 80 form a voltage divider network effectively shunting primaiy winding L1 , only a portion of the ignition voltage between ground and terminal B is applied to sensor coil 23 and the base of Q22. The reactance of capacitor 80 is such as to permit a relatively low voltage to be applied between terminal B and ground. The feedback current to the base of Q22 is of course through capacitor 80. In this circuit, resistor 81 also is used to maintain a ground or negative battery 10 bias to the base of Q22 to maintain 022 in its OFF state until a positive pulse output from sensor winding 23 appears at terminal A to turn Q22 to its ON state, thereby causing the collector of Q22 and the base of Q23 to drop to ground potential to turn ON Q23 and charge primary winding L1. When the negative pulse output of sensor winding 23 arrives at the base of Q22, both Q22 and Q23 are attempted to have their conduction stopped by means of timer 20 action, and a transient current flows through L1 , and a transient voltage develops across L1 and is applied to terminal B to be fed fed back through Q22 and Q23 during the time when turn OFF logic is applied to the base of Q22, there being a normal time delay from the time the turn OFF signal by the timer is issued to the time Q22 and Q23 actually stop conducting. During such delay period, the transient current is recycled several times creating the plurality of pulses as illustraed in FIG. 43, and extending the duty cycle. It should be noted that winding 23 and resistor 81 also act as a voltage divider network insofar as ignition feedback voltage is concerned, thereby also contributing to the limitation of feedback voltage level as applied between the base and emitter of Q22, and maintaining such voltage level to a safe operative value. This circuit using transistors Q22 and Q23, analogous to transistors Q14 and Q15 respectively of FIG. 26 circuit, may utilize transistor types MJE 200, MJE 2801, MJE 4343 or MJE 13009 for Q22, and MJE 210, MJE 2901, MJE 4353, MJE 5852 or MJH 11021 for Q23, made by Motorola, Inc. This circuit being otherwise similar to that of FIG. 26 except for the feedback feature, may also utilize capacitor C shunting secondary L2 as for the FIG. 26 situation. Referring to FIG. 32, this circuit is identical to the circuit of FIG. 31 except for the use of additional resistor 82 therein. Resistor 82 maintains a positive DC bias on the collector of Q22 and on the base of Q23, thereby maintaining the base of PNP transistor Q23 in its OFF state until conduction of Q22 and Q23 starts as described for the circuit of FIG. 31. Referring to FIG. 33, the structure here is the same as illustrated in the FIG. 27 configuration, except that no resistor 16 as in FIG. 27 is utilized in the collector circuit of transistor Q24. This circuit also has Q24 and Q25 transistors of opposite conductivities directly coupled to each other, here transistors Q24 and Q25 have opposite conductivities to those of the circuit of FIG. 31. The input transistor Q24 of PNP type is opposite to the conductivity of transistor Q22 of the NPN type, and transistor Q25 of the NPN type is of opposite conductivity to transistor Q23 of the PNP type. Accordingly, the DC bias potential applied to the input transistors in each case are opposite. For example, resistor 81 is connected to the positive potential of DC source 10 maintaining Q24 in its OFF state until a negative pulse from timer 20 is applied to the base of Q24 to start Q24 conduction and also to start Q25 conduction, analogous to the functions performed by Q22 and Q23 respectively. The transient feedback loop via capacitor 80 to terminal B from primary winding L1 is the same as in the case of FIG. 31 configuration, and its operative characteristics are also the same. Q24 may be selected from the group of transistors MJE 210, MJE 2901, MJE 4353, MJE 5852 or MJH 11021. Q25 may be selected from the group of transistors MJE 200, MJE 2801, " MJE 4343 or MJH 1 009. The performance as illustrated by FIG. 43 and 44 also applies to this configuration. Referring to FIG. 34, such structure is identical to that of FIG. 33 except for the additional resistor 83 providing a ground or negative battery 10 bias to the base of Q25 and maintaining such transistor in quiescent or non-conductive state until action by timer 20 occurs as aforesaid for FIG. 33 situation. The performance of this structure is otherwise the same as for FIG. 33 configuration. Referring to FIG. 35, the circuit herein is the same as that illustrated for FIG. 28, above, excepting that resistor 16 is not used in the collector circuit of transistor Q24. This circuit also is identical to the circuit described for FIG. 33 except that instead of timer 20, a breaker-point contactor timer 30 is utilized to turn transistors Q24 and Q25 ON and OFF. The breaker-point timer operation has already been described in detail in conjunction with FIG. 22 configuration, above. This circuit utilizes the same type of transistors as stated for FIG. 33 configuration. Referring to FIG. 36, this circuit is similar to that of the circuit of FIG. 31 and functions in a similar manner. The difference between these circuits resides in the feedback components. Here - a resistive voltage divider network using relatively high ohmic resistors of very low power rating 84 and 85, minimizes ignition current bleed across primary winding L1. Such divider is tapped off to make connection of capacitor 80, the other side of capacitor 80 being coupled to the base of Q26. Such feedback circuit performs the same function as the feedback circuit of FIG. 31 • The transistors used are the same as those used in the FIG. 31 situation. Referring to FIG. 37, this circuit is identical to that of FIG. 36 and functions in a similar manner. The only difference is the added resistor 82 that maintains a positive DC bias at the base of Q27 to maintain Q27 in its OFF state until timer command is issued to effect conduction of Q26 and Q27 * The transistors herein are identical to those used for FIG. 36 configuration. Referring to FIG. 38, this circuit is identical to that of FIG. 33 except for the feedback structure, which feedback structure utilizes the same structure as for FIG. 36 situation. The transistors Q28 and Q29 are of the same types respectively as transistors Q24 and Q25 of FIG. 33 configuration. Referring to FIG. 39, this circuit is identical to that of FIG. 38, except for the added bias resistor 83 that maintains transistor Q29 in its OFF state until timer command is issued. The transistors herein are the same as in the FIG. 38 situation. Referring to FIG. 40, the circuit herein is identical to that of FIG. 38, except that timer 30 is used instead of timer 20. Timer 30 function has been explained in conjunction with FIG. 22 configuration. Referring to FIG. 41 , this circuit is identical to that of FIG. 29, except for the additional use of transient feedback circuit described in conjunction with FIG. 36 configuration. In this circuit, the base of Q30 is shown as the connection point of the feedback capacitor 80, but the base of Q31 may alternately be used to make such connection. Transistors Q30 and Q31 are the same as specified for FIG. 29 configuration. Transistor 32 may be selected from -the group of transistors MJE 2901 , MJE 4353, MJE 5852 or MJH 11021. The functions are otherwise similar to those function illustrated by FIGS. 43 and 44. Referring to FIG. 42, the circuit herein is the same as the circuit of FIG. 41 » except that timer 20a is used instead of timer 20, and capacitor 80 is used as the transient feedback means connecting the high side of winding L1 to tap M of sensor winding 23. Tap M is intermediate terminals A and B of winding 23. In this manner the L1 induced voltage is divided by capacitor 80 and each portion of winding 23, between tap M and A and between tap M and B. Winding 23 is of relatively high inductance, its DC resistance being in the order of 300 ohms. The transistors herein are identical to those used in the FIG. 41 configuration, and the functional performance is as illustrated by FIG. 43 and 44 * Referring to all figures herein specified, it is understood that capacitor C shown in several of the figures, may be connected and used in conjunction with any of the figures illustrated shunting winding L2, to obtain increased energy output from the ignition transformer. It should also be understood that although a bit more cumbersome, ignition transient feedback signals may be obtained by tapping secondary winding L2- in lieu of primary winding L1.

Claims: CLAIMS 1. An ignition system for a fuel burning engine, said system having a transformer and being characterized by: a pair of semiconductors of opposite conductivities, each of said semiconductors having an input circuit and an output circuit, said output circuits being serially connected; and a primary winding of said transformer connected in series with the serially connected output circuits. 2. The system as stated in claim 1 , including a magnetic pulse timer having an output winding, said output winding being connected to the input circuits. ~ . The system as stat*d in claim 1 , wherein said semiconductors are Darlington type transistors. 4« The system as stated in claim 1, wherein said semiconductors are multijunction type transistors. 5- The system as stated in claim 1, wherein said semiconductors are unijunction type transistors. 6. The system as stated in claim 1 , wherein said semiconductors are field effect type transistors. 7- An ignition system for a fuel burning engine, said system * having a transformer with a primary winding, characterized by: a first semiconductor having input and output circuits; a second semiconductor, of opposite conductivity to the first semiconductor, having input and output circuits, the input circuit of the second semiconductor being connected in series with the output circuit of the first semiconductor, said primary winding being coupled to the output circuit of the first semiconductor; and a timer connected to the input circuit of the first semiconductor. 8. The system as stated in claim 7, wherein the timer is of the magnetic pulse type. ~ . The system as stated in claim 7, wherein the timer is of the point contactor type. 10. The system as stated in claim 7, including: a third semiconductor, of opposite conductivity to the first semiconductor, having input and output circuits, the output circuit of the third semiconductor being series connected with the output circuit of the first semiconductor, said timer being ' connected between the input circuits of the first and third semiconductors. 11. An ignition system for a fuel burning engine, said system having a transformer with a primary winding, characterized by: a semiconductive structure having input and output circuits, the output circuit of said structure being coupled to the primary winding; and means, coupling the transformer to the input circuit of said structure, for providing a feedback signal to said input circuit. 12. The system as stated in claim 11, wherein said structure constitutes first and second transistors, each of said transistors having input and output circuits, the output circuit of the second transistor being coupled to the primary winding, said means coupling the transformer to the input circuit of the first transistor and providng said feedback signal thereto. 13 * The system as stated in claim 11, wherein, said structure constitutes first and second transistors, each of said transistors having input and output circuits, the output circuit of the second transistor being coupled to the primary winding, said transistors being of opposite conductivities, said means coupling the transformer to the input circuit of the first transistor and providing said feedback signal thereto. 14. The system as stated in claim 11, wherein said semiconductive structure constitutes: a first transistor having input and output circuits; and a second transistor, of opposite conductivity to the first transistor, having input and output circuits, the input circuit of the second transistor being connected in series with the output circuit of the first transistor, said means coupling the transformer to the input circuit of the first transistor and providing said feedback signal thereto. 15 * The system as stated in claim 11, wherein said semiconductive structure constitutes: first and second transistors of opposite conductivities, each of the first and second transistors having input and output circuits, the output circuits of the first and second transistors being serially connected; and a third transistor coupled to the serially connected output circuits, said primary winding being coupled to the third transistor, said means coupling the transformer to the input circuit of at least one of said first and second transistors and providing said feedback signal thereto. 16. The system as stated in claim 11, wherein said means constitutes a capacitor. 1 « The system as stated in claim 11 , wherein said means constitutes a capacitor and a resistor connected to said capacitor. 18. The system as stated in claim 11 , wherein said means constitutes a voltage divider network and a capacitor connected to said network. 19. The system as stated in claim 11, including a magnetic pulse timer coupled to the input circuit of said structure. 20. The system as stated in claim 11, including a point contact timer coupled to the input circuit of said structure. 21. The system as stated in claim 11 , including a secondary winding coupled to the primary winding, and a distributed parameter capacitor shunting the secondary winding. 22. A method of increasing the duty cycle duration of an ignition system of a fuel burning engine, characterized by the steps of: (a) triggering an electronic circuit and developing a transient signal in a transformer primary winding connected to said circuit; and (b) feeding back a portion of said transient signal to the input of the electronic circuit. 23« The method as stated in claim 22, including the step of: (c) passing said transient signal through said electronic circuit and developing ignition energy of increased duty cycle in said primary winding, subsequent to step (b). 24« The method as stated in claim 23, including the further step of: (d) transferring said ignition energy to at least one igniter, subsequent to step (c).

Inventors: GERRY MARTIN E, GERRY, MARTIN, E.
Applicants: GERRY MARTIN E, GERRY, MARTIN, E.
Application year: 1985
Main classification: F02B23
IPC codes: F02P3