IGNITION DEVICE FOR INTERNAL COMBUSTION ENGINE

• US 3,563,221 A
• Filed: 02/14/1969
• Issued: 02/16/1971
• Est. Priority Date: 02/19/1968
• Status: Expired due to Term

• Current Assignee: Tada Yasuo
• Original Assignee: Tada Yasuo
• Inventors: TADA YASUO
• Application Number:
  US04/799,260
• Time in Patent Office: 732 Days
• US Class Current: 123/598
• CPC Class Codes: F02P 15/12 having means for strengthening spark during starting
• CPC Class Codes: F02P 3/0838 with semiconductor devices F02P3/0861, F02P3/0884, F02P3/093 take precedence
• CPC Class Codes: F02P 3/0884 Closing the discharge circuit of the storage capacitor with semiconductor devices

Abstract

A low DC voltage boosted by an inverter and a rectifier charges a capacitor a charge on which is, in turn, discharged into an ignition coil under control of a thyristor. Upon starting the engine, the DC voltage is applied to an intermediate terminal of a primary transformer winding in the inverter. Diodes are connected in a circuit for gating the thyristor to prevent the circuit from partly short-circuiting the primary winding through the intermediate terminal.

Claims

1. An ignition device for use with an internal combustion engine, comprising, in combination:

1. a source of direct current;

2. inverter means including a transformer comprising a saturable magnetic core, an input winding, an output winding and a feedback winding, all said windings being inductively disposed around said magnetic core and a transistor connected to both said input winding and said feedback winding;

3. said primary winding having an end terminal and an intermediate terminal presenting to said output winding a turn ratio higher than does said end terminal;

4. a first conductor connected to said end terminal of said primary transformer winding and capable of being energized by said source;

5. a second conductor connected to said intermediate terminal of said primary transformer winding and capable of being energized by said source;

6. a transfer switch connected between said source and said first and second conductors such that, the same connects said source to said second conductor upon starting the engine and to said first conductor after the engine has been started and when it is in operation;

7. a rectifier for rectifying the output of the output winding of said transformer and an ignition capacitor charged with the rectified output of the output winding of said transformer of said inverter means;

8. an ignition coil including a primary winding and a secondary winding inductively coupled to each other, said primary winding having one end connected to said ignition capacitor;

9. a thyristor for controlling said ignition capacitor and operative in its closed state to permit said ignition capacitor to be discharged into said primary ignition coil winding to produce an ignition voltage across said secondary coil ignition winding, said thyristor having a control terminal;

10. a gating circuit controlling said thyristor and having an input terminal, means operable in synchronism with the rotation of the engine to produce a gating signal and an output terminal connected with the control terminal of said thyristor;

anD 11. a pair of semiconductor diodes having input and output terminals, means connecting the output terminals of both of said diodes to the input terminal of said gating circuit, means connecting the input terminal of one of said diodes with said first conductor, and means connecting the input terminal of the other of said diodes with said second conductor.

2. An ignition device as claimed in claim 1, wherein said transformer of said inverter means includes additionally another of said inverter means includes additionally another input winding and a separate feedback winding inductively disposed around said magnetic core, and wherein another transistor is connected to both said another input winding and said separate feedback winding, said transistors being alternately turned on and off.

3. said primary winding having an end terminal and an intermediate terminal presenting to said output winding a turn ratio higher than does said end terminal;

4. An ignition device as claimed in claim 1, wherein said gating circuit includes a set of contacts capable of being open and closed in synchronization with the rotation of the engine, a gating capacitor charged by said source upon the opening of said set of contacts, and a resistor connected to said gating capacitor to be traversed by a charging current for the latter to produce a voltage applied as a gating signal to said thyristor.

5. a second conductor connected to said intermediate terminal of said primary transformer winding and capable of being energized by said source;

6. a transfer switch connected between said source and said first and second conductors such that, the same connects said source to said second conductor upon starting the engine and to said first conductor after the engine has been started and when it is in operation;

7. a rectifier for rectifying the output of the output winding of said transformer and an ignition capacitor charged with the rectified output of the output winding of said transformer of said inverter means;

8. an ignition coil including a primary winding and a secondary winding inductively coupled to each other, said primary winding having one end connected to said ignition capacitor;

9. a thyristor for controlling said ignition capacitor and operative in its closed state to permit said ignition capacitor to be discharged into said primary ignition coil winding to produce an ignition voltage across said secondary coil ignition winding, said thyristor having a control terminal;

10. a gating circuit controlling said thyristor and having an input terminal, means operable in synchronism with the rotation of the engine to produce a gating signal and an output terminal connected with the control terminal of said thyristor;

anD

11. a pair of semiconductor diodes having input and output terminals, means connecting the output terminals of both of said diodes to the input terminal of said gating circuit, means connecting the input terminal of one of said diodes with said first conductor, and means connecting the input terminal of the other of said diodes with said second conductor.