US3034018A - Transistorized breakerless ignition system - Google Patents

Description

y 1962 M. l. ROSENBERG 3,034,018

TRANSISTORIZED BREAKERLESS IGNITION SYSTEM Filed Dec. 18, 1959 4 Sheets-Sheet 1 S P S P S P S P s P 5 P S P S P L. l .L 1 ..L

PLUG ARRANGEMENT INVENTOR- b;;.; M EETON I. ROSENBERG ATTO/PNEX y 1952 M. I. ROSENBERG 3,034,018

TRANSISTORIZED BREAKERLESS IGNITION SYSTEM Filed Dec. 18, 1959 4 Sheets-Sheet 2 TO TR ANS FORMEK F19 ENERGY CONTROL l TO DlSTEIBUTOE INVENTOR. To PULSE GEN. MERTON I. ROSENBERG fig 4404;

ATTOP/VCK y 8, 1962 M. l. ROSENBERG 3,034,018

TRANSISTORIZED BREAKERLESS IGNITION SYSTEM Filed Dec. 18, 1959 4 Sheets-Sheet 3 INVENTOR. MERTON I. EOSENBE?G ATTOFNEY May 8, 1962 M. 1. ROSENBERG 3,034,018

TRANSISTORIZED BREAKERLESS IGNITION SYSTEM Filed Dec. 18, 1959 4 Sheets-Sheet INVENTOR.

- ME'RTON a. ROSENBERG A TTOPNEK 3,934,018 TRANSHSTGRXZED BREAKERLESS TGNITTGN SYSTEM Merton I. Rosenberg, West Springfield, Mass, assignor to American Bosch Anna Corporation, a corporation of New York Filed Dec. 18, 1959, Ser. No. 86%,581 11 Claims. (Cl. 315-265) This invention relates to a new and improved battery type ignition system for spark ignition internal combustion engines.

The principal object of the invention is to provide a new and improved ignition system of the type set forth which is relatively simple and economical in construction, yet efiicient in operation.

An object of the invention is to provide a new and improved battery type ignition system which eliminates breaker or interrupter contacts and condensers and which achieves high engine efficiency through better combustion due to the ability of the system to provide and maintain optimum timing of injection firing.

Another object is to provide a new and improved battery type spark ignition system which will operate successfully on any multi-cylinder engine.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings, wherein the preferred forms of the invention have been set forth by way of illustration only.

Referring to the drawings:

FIG. 1 is a schematic circuit diagram of an ignition system embodying the invention;

FIG. 2 is a schematic view of a modified form of the invention;

FIG. 3 is a schematic showing a modified form of a circuit; and

FIGS. 4 and 5 are perspective views, partially in section, illustrating the adaptation of the system to the ignition distributor of an internal combustion engine.

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout and wherein the system has been shown as applied to an eight-cylinder engine by way of example, the system shown in FIG. 1 is a high tension system adapted for use on automotive, truck, marine engines, etc., whereas the arrangement shown in FIG. 2, which is of a much more expensive type, is intended for use on stationary gasoline, natural gas, LP gas engines, etc., where spark is a hazard and all spark, even on starting, is preferably eliminated.

The form of the invention shown in FIG. 1 comprises a magnetic pulse generator rotor PG which is preferably of permanent magnet material such as Alnico V magnetized properly. The rotor is in fixed relation with the engine timer shaft F and set physically in timed phase with the distributor arm D.

The pulse generator rotor PG is provided with a pair of pole shoes for each engine cylinder to be ignited, with each pair of pole shoes comprising a north and south pole which are labeled N and S, respectively, in the drawings.

The apparatus is provided with a distributor contact C for each engine cylinder and the distributor contacts C are each connected by an electrical lead L to a respective spark plug SP for each respective engine cylinder.

Adjacent the periphery of the rotor PG is provided a control coil CC in which is induced a pulsing voltage by the rotor PG.

The rotor PG is connected to the transformer TR by the lead K. The transformer TR comprises a primary P and a sectional wound secondary of the type sometimes referred to as Pie wound secondary.

The circuit includes the usual D.C. battery which is indicated as DC. and the usual ignition switch which is indicated as SW.

The switching circuit comprises a power transistor T which may be of the germanium or silicon type, whose emitter terminal E is connected to the positive side of the DC. source through a silicon rectifier RE in the direction shown through the DC. source to ground. The collector terminal C of the main power transistor T is connected in series with the primary winding P of the transformer TR to ground. The base terminal B of the power transistor T is connected in series with the emitter terminal E of the triggering transistor T The collector terminal C of the triggering transistor T is connected to ground.

The base terminal B of triggering transistor T is connected to one side of the control coil CC through the control coil to the emitter terminal E of transistor T and connected across the control coil CC is a zener diode Z The secondary winding S of transformer TR is connected in parallel with the spark electrodes, one of which is at ground potential.

In the operation of the system, as the ignition switch SW is closed, the starting motor turns the engine cam which, in turn rotates the pulse generator rotor PG. The magnetic rotor PG then induces a pulsing voltage in the control coil CC located in the base of the emitter circuit of the triggering transistor T Thus, it is understood that the pulse is synchronized with the travel of the piston in the particular cylinder which is to be fired, which synchronization is arranged so that the maximum voltage is obtained from the pulse generator at approximately the same time that the piston is at a position slightly before top dead center of its compression stroke. This causes transistor T to rapidly switch on which, in turn, causes transistor T to rapidly switch on subjecting the primary P of transformer TR to a current transient, which in turn,

causes a voltage transient in the primary which, when transformed to the secondary S, will cause the spark plug to fire at the proper instant. The change in flux with respect to time, when multiplied by the inductance (Faradays law) is such that enough voltage is available to cause the desired breakdown when transformed by the transformer TR.

The rectifier RE, located in the emitter circuit of the power transistor T is provided to cause a constant voltage drop regardless of the current flowing through it. The resistor R is provided to stabilize the power transistor and is determined by the stability factor for this transistor. The overall function of the rectifier RE and the resistor R is to stabilize the circuit and provide a means of reducing heat due to its own current carrying capabilities.

A resistor could replace the rectifier RE under certain conditions, but would not contribute a constant voltage drop.

The zener diode Z has two functions, the first of which is to limit the amplitude pulse voltage produced by the pulse generator PG and, second, to eliminate the negative half cycle of the pulse.

The transformer is designed so that the kick-back voltages will not exceed the collector C to emitter E voltage of the transistor T otherwise known as the transistor punch-through voltage. The secondary of the transformor TR is designed such that the reactance (capacitive) due to the proximity of the secondary winding is reflected back as an impedance that approaches infinity or high enough so that very little of the primary current is absorbed due to this reflected impedance. This is accomplished by sectioning the secondary winding, or sometimes referred to as a pi (1r) winding.

In FIG. 3, a modified form of circuit is shown in which Patented May 8, 1962' e3 there :is provided. antenergy control means which may be in the form of a variable potentiometer.

In the form of the invention shown in FIGS. 2 and 4, there is shown a system which is particularly adapted for low tension distribution for such'uses' as for stationary gasoline engines, natural gas engines, LP. gas engines, etc. where spark is a hazard and no spark is desired, even for starting.

*In this form oftheinvention the magnetic rotor PG has only a single pair of poles N and. S, in which event it may be preferablezto provide a balance B for the rotor and surrounding the rotor are provided separate control coils CC for each engine cylinder, and the coils are adapted to be connected byJthe leads A and B to a separate circuit such as shown in FIG. 3 andconsisting of a separate transformer TR and power transistor T and triggering transistor T for each control coil'CC. All of the systems are connected to a single battery or. DC power source. In this form, the pulse generator PG serves to trigger the transistors. 1

-The systems of FIGS. 1 and 2 arecompatible and the operation of the form of 'FIG. 2 is the same as explained above.

- In, the circuit shown in FIG. 3, there is shown avari able resistor inthe. collector C .circuit of transistor T This is provided as an adjustment for the energy level of theisystemby being able to control the flow of current. This iszan additional:feature whichhas a limit because reducing the energy. too much will create a reduction in outputvoltage.

BIG; 4showsa-practical adaptation of alow tension systemsuch as shown diagrammatically in FIG. 2.

1 FIG. SIiIlustrates a practical adaptation of thesystem shown: schematically in FIG. 1" andin this system the magneticzrotor PG- may. be provided with pole shoes in thelformuofa soft iron castings G which are formed separatelyrand are then positioned over rotor PG and securedthereto by'any'suitable means, such as press fit or byssoldering, welding or other suitable means. The castings' G'havexthe pole shoes'Nwand S integral therewith and itis'onlynecessary-to properlyorient the castings G on the rotor PGwith the pole shoes. in proper relation.

It has been found that in a twelve-volt ignition system with av twelve-volt battery D.C. that the components may have the following characteristics:

Ratio of P110 S-m=6 Zi-- l volt zener diode Permanent'magnet rotor PG--Alnico V Accordingto this system, the transistor along with the permanent magnet type pulse generator replaces the contactsand condenser used in present battery type spark ignition engines. It provides maintenance-free ignition for the engine along with high performance. The small pulse type generator induces a voltagein the triggering transistor which causes'this transistor to conduct. This is. accomplished each time a pair of poles sweep by a control coil located in. theemitter to base circuit of the tran sistor. This causes the main power transistor to conduct by lettingits base circuit conduct. This main power transsistor. is non-conductive when its base circuit is open. This offers afmake type of arrangement in the system. Durin'g this make type of arrangement, the collector circuit'in series with the primary is subjected to a transient pulse of current which causes a transient voltage according to Faradays law. The time constant of this pulse is limited onlyby the pulse generator control coil and the primary winding since the time response of the transistors is a great deal faster. This transient voltage is then transformed to the secondary and appears across the spark plug electrodes causing the spark plug to fire. Since the rotor of the pulse generator is geared directly to the engine and is physically set in time phase with the distributor, the timing is preset and will follow the engine speed without any need for adjustment,

It will be seen that the foregoing ignition system inherently possesses certain advantages, such as greatly increasing spark plug life due to the reduction of multiple sparking or firing, which is inherently reduced by this system.

Furthermore, with the present system constant output voltage is obtained over the entire engine speed range,- thus making it possible to obtain betterefficiency at higher speeds, which is the opposite to conventional systems.

Another advantage of the present system'is that it is a make type of circuit and it draws energy from the bat-- teryonly when the circuit is conductive, thus drawing less current from the battery.

From the foregoing it willbe seen that I have provided new and improved means for obtaining all of the objects and advantages of the invention.

Iclaim:

1. In an ignition system for an internal combustion engine, a pulse generator having a rotor having north and south poles, coil means adjacent the periphery of said rotor and'adapted to have a pulse induced therein by said poles of said rotor upon relative rotation of said rotor and coil-means, a source of direct current, a transistor switching circuit connected to said coil means and'to said source of current, transformer means having a sectional wound secondary, said transformer means being connected to said source of current'through said. switching circuit, said transistor switching circuit comprising a cascaded transistor switching arrangement, whereby said pulse generator produces a pulse in said transistor circuit causing the transistors of said transistor circuit to conduct and allow a flux field to be built up in the primary of said transformer for a predetermined time whereupon flow. of current willbe terminated and flux field will collapse inducing a voltage which will be transformed by said transformer and providethe desired ignition voltage.

2. In an ignition system for an internal'combustion engine, a pulse generator having a rotor having a plurality of spaced pairs of poles, one of said pairs of poles being utilized for each engine cylinder, a coil adjacent the pcriphery of said rotor and adapted to have a pulse induced therein by each of said pairs of poles upon relative rotation of said coil-and said pairs of poles, a distributor arm operatively connected to said rotor and adapted to be rotated upon rotation of said'rotor, a plurality of contacts, one of said contacts being provided for each pair of poles, each ofsaid contacts being adapted to be connected to a respective ignition means for igniting a charge in a respective engine cylinder, a source of direct current, a transformer, the high tension side of said transformer beingelectricall'y connected to said distributor arm, a cascaded transistor switching arrangement directly coupled to said coil and adapted to'connect said source ofcurrent to said transformer said coil being connected to one of said transistors, said transistor having its base and emitter electrodes in series between the base electrode and ground, whereby said pulse generator produces a pulse in said transistor circuit'causing the transistors of said transistorcircuit to conduct and allow a flux field to be built up in the primary of said transformerfor a predetermined time whereupon flow of current will be terminated and flux field will collapse inducing a voltage which will be of spaced pairs of poles, one of said pairs of poles being utilized for each engine cylinder, a coil adjacent the periphery of said rotor and adapted to have a pulse induced therein by each of said pairs of poles upon relative rotation of said coil and said pairs of poles, a distributor arm operatively connected to said rotor and adapted to be rotated upon rotation of said rotor, a plurality of contacts, one of said contacts being provided for each pair of poles, each of said contacts being adapted to be connected to a respective ignition means for igniting a charge in a respective engine cylinder, a soure of direct current, a transformer the high tension side of said transformer being electrically connected to said distributor arm, a cascaded transistor switching arrangement adapted to connect said source of current to said transformer, said coil being connected to one of said transistors, said transistor having its base and emitter electrodes in series between the base electrode and ground, whereby said pulse generator produces a pulse in said transistor circuit causing the transistors of said transistor circuit to conduct and allow a flux field to be built up in the primary of said transformer for a predetermined time whereupon flow of,

current will be terminated and flux field will collapse inducing a voltage which will be transformed by said transformer and provide the desired ignition voltage, said transformer having a sectional wound secondary to reduce capacitance due to proximity of secondary windings.

4. In an ignition system for an internal combustion engine, a pulse generator having a rotor having a plurality of spaced pairs of poles, one of said pairs of poles being provided for each engine cylinder, a coil adjacent the periphery of said rotor and adapted to have a pulse induced therein by each of said pairs of poles upon relative rotation of said coil and said pairs of poles, distributor means operatively connected to said rotor and adapted to be rotated upon rotation of said rotor, a plurality of spaced contacts, one of said contacts being provided for each engine cylinder and being connected to an ignition means for said cylinder, a source of direct current, a transformer connected to said distributor means for supplying energy thereto, said source of current being connected to said transformer through a cascaded semiconductor switching arrangement, said transformer having a sectional wound secondary to reduce capacitance due to proximity of secondary windings.

5. In an ignition system for an internal combustion engine, a pulse generator having a rotor having north and south poles, coil means adjacent the periphery of said rotor and adapted to have a pulse induced therein by said poles of said rotor upon relative rotation of said rotor and coil means, a source of direct current, a transistor switching circuit for each engine cylinder and connected to a respective coil means and to said source of current, transformer means connected to said source of current through said switching circuit, said transformer having a sectional wound secondary, said transistor switching circuit comprising a cascaded transistor switching arrangement, whereby said pulse generator produces a pulse in said transistor circuit causing the transistors of said transistor circuit to conduct and allow a flux field to be built up in the primary of said transformer for a predetermined time whereupon flow of current will be terminated and flux field will collapse inducing a voltage which will be transformed by said transformer and provide the desired ignition voltage.

6. In an ignition system for an internal combustion engine, a pulse generator having a rotor having north and south poles, coil means adjacent the periphery of said rotor and adapted to have a pulse induced therein by said poles of said rotor upon relative rotation of said rotor and coil means, a source of direct current, a transistor switching circuit for each engine cylinder and connected to a respective coil means and to said source of current, transformer means connected to said source of current through said switching circuit, said transformer having a formed by said' transformer and provide the desired ignition voltage.

7. In an ignition system for an internal combustion engine, a pulse generator having a rotor having a plurality of spaced pairs of poles, one of said pairs of poles being utilized for each engine cylinder, a coil adjacent the periphery of said rotor and adapted to have a pulse induced therein by each of said pairs of poles upon relative rotation of said coil and said pairs of poles, a distributor arm operatively connected to said rotor and adapted to be rotated upon rotation of said rotor, a plurality of contacts, one of said contacts being provided for each pair of poles, each of said contacts being adapted to be connected to a respective ignition means for igniting a charge in a respective engine cylinder, a source of direct current, a transformer, the high tension side of said transformer being electrically connected to said distributorv coil being connected to one of said transistors, said transistor having its base and emitter electrodes in series be tween the base electrode and ground, whereby said pulse generator produces a pulse in said transistor circuit causing the transistors of said transistor circuit to conduct and allow a flux field to be built up in the primary of said transformer for a predetermined time whereupon flow of current will be terminated and flux field will collapse inducing a voltage which will be transformed by said transformer and provide the desired ignition voltage.

8. In an ignition system for an internal combustion engine, a pulse generator having a rotor having a plurality of spaced pairs of poles, one of said pairs of poles being provided for each engine cylinder, a coil adjacent the periphery of said rotor and adapted to have a pulse induced therein by each of said pairs of poles upon relative rotation of said coil and said pairs of poles, a distributor arm operatively connected to said rotor and adapted to be rotated upon rotation of said rotor, a plurality of contacts, one of said contacts being provided for each pair of poles, each of said contacts being adapted to be connected to a respective ignition means for igniting a charge in a respective engine cylinder, a source of direct current, a transformer, the high tension side of said transformer being electrically connected to said distributor arm, said transformer having a pi wound secondary, a cascaded transistor switching arrangement adapted to connect said source of current to said transformer, said coil being connected to one of said transistors, said transistor having its base and emitter electrodes in series between the base electrode and ground, whereby said pulse generator produces a pulse in said transistor circuit causing the transistors of said transistor circuit to conduct and allow a flux field to be built up in the primary of said transformer for a predetermined time whereupon flow of current will be terminated and flux field will collapse inducing a voltage which will be transformed by said transformer and provide the desired ignition voltage.

9. In an ignition system for an internal combustion engine, a pulse generator having a rotor having a pair of north and south poles, a plurality of coil means adjacent the periphery of said rotor and adapted to have a pulse induced therein by said poles of said rotor upon relative rotation of said rotor and coil means, each of said coil means being adapted to be connected to the igniting means'of the internal combustion engine, a source of direct current, a transistor switching circuit for each the periphery of said rotor and adapted to have a pulse induced therein by said poles of said'rotor upon relative rotation of'said rotor and coil means, each of said coil means being :adapted to be connected to the igniting means of the internal combustion engine, a source of direct current, a transistor switching circuit for each engine cylinder and. connected to a respective coil means and to said source of current, and transformer means for each of said coil means connected to said source of current through said switching circuit for eachrespective coil means, said transistor switching circuits each comprising a cascaded transistor switching arrangement.

11. In an ignition system for an internal combustion engine, a pulse generator having a rotor having a plurality of spaced pairs ofpoles, one of said pairs of poles being utilized for each engine cylinder, a coil adjacent the periphery of said rotor and adapted to have a pulse.

induced therein by each of said pairs of poles upon re1ativer'otation of said coil and said pairs of poles, avdistributor arm operatively connected to said rotor and i: adapted to be rotated rupon rotation of said rotor, a plurality of contacts, one of said contacts being provided for each pair of poles, each of saidcontacts being adapted to be connected .to respective ignition means for igniting a charge in a respective engine cylinder, a source of direct current, atransformer, the high tension side of said transformer being electrically connected to said distributor arm, a cascaded transistor switching arrangement directly coupled to said coil and adapted to connect said source of current to said transformer, said coil being connected to one of said transistors.

ReferencesCited in the file of this patent UNITED STATES PATENTS 2,430,379 Wall Nov. 4, 1947' 2,852,588 Hartman Sept. 16, 1958' 2,852,589 Johnson Sept. 16, 1958 2,858,456 ,Royer et al. Oct. 28, 1958 2,863,069 -Campanella Dec. 2, 1958 2,864,985 Beck Dec. 16, 1958 2,878,298 Giacoletto Mar. 17, 1959 2,911,566 Taylor et al. Nov. 3, 1959 2,915,649 Cagle' Dec. 1, 1959 2,953,719 Guiot Sept. 20, 1960 v V FOREIGN PATENTS.

1,137,949 France -d Jan. 211, 1957

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