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Publication numberUS3367314 A
Publication typeGrant
Publication dateFeb 6, 1968
Filing dateSep 8, 1965
Priority dateSep 16, 1964
Also published asDE1464053B1
Publication numberUS 3367314 A, US 3367314A, US-A-3367314, US3367314 A, US3367314A
InventorsYoshiaki Hirosawa
Original AssigneeHonda Gijutsu Kenkyusho Kk
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Non-contact ignition device
US 3367314 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

Feb. 6, 1968 YOSHIAKI HIROSAWA ETAL 3,367,314

NONCONTACT IGNITION DEVICE Filed Sept. 8. 1965 United States Patent 3,367,314 NON-CONTACT IGNITION DEVICE Yoshiald Hirosawa, Tokyo, Takaya Senzaki, Yamatomachi, Kita-adachi-gun, Saitarna Prefecture, Japan, assignors to Kahushilri Kaislia Honda Gijutsu Kenkyusho, Saitama Prefecture, Japan, a corporation of Japan Filed Sept. 8, 1965, Ser. No. 485,859

Claims priority, application Japan, Sept. 16, 1964,


3 Claims. (Cl. 123-148) ABSTRACT OF THE DISCLOSURE The invention comprises an electrical ignition system for internal combustion engines wherein an A.C. generator source charges a condenser through half-wave rectifier means and an SCR is switched on to discharge the condenser via the primary ignition coil thereby producing a firing spark. The switching circuit for the SCR comprises a constant voltage diode and a resistor connected in series therewith, the combination being in parallel with the SCR. A connection from the junction of the diode and resistor extends to the gate of the SCR so that when a predetermined voltage level in the half-wave signal is reached, the diode current causes a pulse to the gate for firing the SCR which in turn provides the discharge path for the condenser.

This invention relates to a non-contact ignition device for internal combustion engines, wherein the charging and discharging of condenser, as well as the switching of semiconductor elements are utilized.

More particularly the present invention relates to the type of non-contact ignition device wherein an output current of an A.C. generator, such as a magneto generator, which is rotated synchronously with the internal combustion engine, is rectified to charge a condenser and the charged condenser is discharged by means of a switching circuit comprising a silicon controlled rectifier (which hereinafter is abbreviated to SCR) through a primary coil of the ignition coils so that high voltage or tension induced in a secondary coil may be applied to a plug.

A first object of the present invention is to provide an improved non-contact ignition device of the type referred to above wherein a separate or further generator, synchronized with said first mentioned generator as means for feeding a positive signal current to the gate of the SCR,

is eliminated because the condenser or capacitor is discharged by actuating the SCR switching circuit in synchronism with the rotation of the output shaft of the internal combustion engine.

A second object of the present invention is to provide such a device wherein the time when said signal gate current is supplied, that is, the time for igniting can be easily controlled, which object may be achieved concurrently with said first object.

A third object is to provide such a device wherein the pulse circuit in the condenser charging and discharging type ignition device for accomplishing the foregoing objects may be easily constructed.

Further features and advantages of the present invention will be clear from the following explanation of the invention in detail in connection with the accompanying drawings, in which:

FIG. 1 is a connection diagram of the circuit according to the present invention; and

FIG. 2 shows the operational characteristics of the constant voltage diode according to the present invention,

Patented Feb. 6, 1968 wherein time is represented along the abscissa and voltage along the ordinate.

Referring to an embodiment of this invention as illustrated in the drawings, an alternative-current generator 1, such as a magneto generator, is mechanically connected with the output shaft of an internal combustion engine. A half-wave rectifier 2 is connected to generator 1 for rectifying its A.C. output. A condenser or capacitor 3 is connected in parallel with generator 1. A primary coil 4 and a secondary high tension coil 5 comprises the ignition coils. A semiconductor controlled rectifier 6 (SCR) provides the discharge path for capacitor 3.

The gate G of said SCR 6 is supplied with pulses, so as to discharge the condenser 3 synchronously with rotation of the internal combustion engine, and induce high tension or voltage in the secondary coil 5, in order to ignite a plug 7.

It is well known to use another signal generator rotating synchronously with the generator 1 as means for getting the gate signal. It is, however, uneconomical to provide two generators.

The present invention eliminates, the additional generator and accomplishes the same purpose with a simple circuit construction. A constant voltage diode 8 is electrically connected between an anode A of the SCR 6 and the gate G. When the voltage at the anode reaches at a certain or predetermined level, an ignition gate signal is given to the gate G by Zener current from the constant voltage diode 8 so as to turn on SCR 6. A resistor 9 is connected in series between the constant voltage diode 3 and earth E or the common return line.

The A.C. output from the generator 1 is rectified by the rectifier 2, so that the condenser or capacitor 3 is charged, and simultaneously, equivalent voltages are applied to the anode A of SCR and also to the constant voltage diode 8. When the anode potential V is reached, a predetermined Zener voltage in the constant voltage diode 8 as shown in FIG. 2, causes the Zener current suddenly to flow through the resistor 9. SCR 6 is turned-on by appropriately selecting the current passing through the :gate G by the resulting fall of voltage so as to discharge the charged potential of the condenser 3 through the primary coil 4. When the time t (FIG. 2) has elapsed during the discharge, SCR 6 is turned off. The above-mentioned operation is repeated per each cycle of output current from the generator 1.

In the present invention the ignition is performed synchronously with the rotation of the internal combustion engine. Thus, with increase of r.p.m. of the internal combustion engine, the frequency of out-put current of the generator correspondingly increases which is shown in broken curve V in FIG. 2. It will be clear that the control of ignition time may be easily effected by regulating the resistance value of the resistor 9 and consequently the current passing the gate G is correspondingly controlled so as to adjust the turning-on time of SCR.

In lieu of the constant voltage diode 8, a resistor may be theoretically used. However, due to high power consumption and the difficulty of charging the condenser up to a sufliciently high potential and further as the operation is unstable and the sparking energy is low, and so forth, the use of a resistor replacement for diode 8 is impractical for this purpose.

What is claimed:

1. A non-contact ignition device comprising an A.C. generator including an output circuit, a half-wave rectifier connected in the output circuit of said generator, a primary ignition coil and a silicon controlled rectifier having an anode and a cathode and a gate, the anode-cathode being connected in series with rectifier, a condenser connected between the half-wave rectifier and the primary coil in parallel with said silicon controlled rectifier, a secondary coil coupled to the primary coil for producing a spark upon condenser discharge a constant voltage diode, a resistor connected in series with said diode, and said diode and resistor being connected in parallel with the anode-cathode of the silicon controlled rectifier, and a connection from the junction of the resistor and diode to said gate.

2. An ignition system for an internal combustion engine operative from the engine output shaft comprising, in combination A.C. generator means, means connected to the generator for half-wave rectifying the A.C. output, condenser means connected in parallel with the generator means to be charged by the rectified output, an SCR having an anode and a cathode and a gate, a primary ignition coil, said coil and the anode and cathode of the SCR being connected in series with the rectifying means, secondary ignition coil means for developing a high voltage discharge upon discharge of the condenser means, a switching circuit for the SCR, said circuit comprising a constant voltage diode and a resistor connected in series, and a connection from between the diode and resistor to the gate for supplying a pulse to the gate to turn the SCR References Cited UNITED STATES PATENTS 2,030,228 2/1936 Randolph et a1 123148 2,071,573 2/1937 Randolph et al 123148 2,151,796 3/1939 Peters 123148 2,203,579 6/1940 Randolph 123148 OTHER REFERENCES Solid State Products Incorporation, One Pingres St. Salem, Mass, Bulletin D 420-02, August 1959, pages 17-18 (Figure 27).

Solid State Products Incorporation, Bulletin D 4211-02, September 1960, pages 15 and 16 (Figure 22).

20 LAURENCE M. GOODRIDGE, Primary Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2030228 *May 1, 1933Feb 11, 1936 Spark generating system
US2071573 *May 28, 1934Feb 23, 1937Gen Motors CorpIgnition system
US2151796 *Dec 31, 1936Mar 28, 1939Westinghouse Electric & Mfg CoDischarge apparatus
US2203579 *Mar 11, 1939Jun 4, 1940General Motors CorporationIgnition circuit
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3446197 *Jul 12, 1967May 27, 1969Battelle Development CorpIgnition system for free-piston engine
US3490426 *Jul 20, 1967Jan 20, 1970Tecumseh Products CoIgnition system
US3500809 *Apr 29, 1968Mar 17, 1970Bosch Gmbh RobertIgnition arrangement for internal combustion engines
US3553529 *May 1, 1968Jan 5, 1971Bosch Gmbh RobertCondenser discharge type ignition system with a magneto power supply
US3576467 *Aug 31, 1967Apr 27, 1971Penn ControlsHigh voltage spark generator from low voltage supply
US3620200 *Jul 8, 1969Nov 16, 1971Ambac IndBooster circuit for ignition systems
US3620201 *Oct 7, 1969Nov 16, 1971Warren Glenn BSolid state multispark ignition system
US3623466 *Aug 6, 1969Nov 30, 1971Palmer William FCurrent transfer electrical system
US3646667 *Jun 18, 1970Mar 7, 1972Tecumseh Products CoIgnition circuit
US3661132 *Dec 15, 1969May 9, 1972Tecumseh Products CoIgnition circuit with automatic spark advance
US3677253 *Aug 20, 1970Jul 18, 1972Nippon Denso CoCapacitor discharge type ignition system for internal combustion engines
US3703889 *Oct 22, 1970Nov 28, 1972Bosch Gmbh RobertIgnition arrangement for internal combustion engines
US3704700 *Jan 15, 1971Dec 5, 1972Bosch Gmbh RobertIgnition arrangement for internal combustion engines having an alternating current generator
US3718125 *Apr 5, 1971Feb 27, 1973Posey TCapacitor discharge ignition system
US3866589 *Feb 8, 1973Feb 18, 1975Bosch Gmbh RobertSemiconductor controlled magneto ignition system for internal combustion engines
US3871348 *Feb 7, 1973Mar 18, 1975Outboard Marine CorpCapacitive discharge ignition system for internal combustion engines
US3880133 *Apr 27, 1973Apr 29, 1975Kokusan Denki CoBreakerless ignition system
US3911887 *Feb 19, 1974Oct 14, 1975Phelon Co IncCapacitor discharge ignition system
US3933139 *Jan 22, 1971Jan 20, 1976The Economy Engine CompanyCapacitive discharge ignition system
US3933140 *Jul 25, 1973Jan 20, 1976Syncro CorporationCapacitive discharge ignition adapter
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US3951122 *Jun 18, 1974Apr 20, 1976Robert Bosch G.M.B.H.Ignition system for internal combustion engine and method to generate ignition pulses
US4029998 *Mar 3, 1975Jun 14, 1977Mcculloch CorporationCapacitor discharge ignition circuit
US4056088 *Apr 12, 1974Nov 1, 1977Syncro CorporationIgnition system
US4141331 *Oct 21, 1974Feb 27, 1979W. R. Grace & Co.Breakerless capacitive discharge ignition system
US4213436 *Sep 13, 1978Jul 22, 1980R. E. Phelon Company, Inc.Capacitor discharge ignition and alternator auxiliary power system
US5069193 *Jul 19, 1990Dec 3, 1991Prufrex-Elektro-Apparatebau Inh. Helga Muller geb. DutschkeIgnition process, arangement and apparatus for internal combustion engines with a magneto
US5954027 *Sep 30, 1997Sep 21, 1999Sanshin Kogyo Kabushiki KaishaSensor for engine control
US6191536 *Dec 8, 1994Feb 20, 2001Unison Industries, Inc.Solid-state ignition system using true voltage triggering
US7084528 *Jun 9, 2003Aug 1, 2006Ngk Insulators, Ltd.High-voltage pulse generating circuit
US7414333Jun 6, 2006Aug 19, 2008Ngk Insulators, Ltd.High-voltage pulse generating circuit
US7482786Dec 5, 2005Jan 27, 2009Ngk Insulators, Ltd.Electric discharger using semiconductor switch
US7489052Nov 17, 2004Feb 10, 2009Ngk Insulators, Ltd.High voltage pulse generating circuit
U.S. Classification123/600, 315/209.00R, 327/445, 315/209.0SC, 123/655
International ClassificationF02P1/00, F02P1/08
Cooperative ClassificationF02P1/086
European ClassificationF02P1/08C