Claims
- 1. A high voltage generating circuit for an automotive ignition system including at least one spark plug, comprising:
- a power source;
- a current control circuit coupled to said power source for generating a linearly increasing current signal;
- controlled high frequency switching means coupled to said current control circuit for initiating generation of said linearly increasing current signal, said controlled high frequency switching means having an output in the form of a high frequency voltage and a high frequency linearly increasing current;
- ignition transformer means adapted to be coupled to said spark plug and connected to the output of said switching means for stepping up said high frequency voltage supplied from said switching means for application to said spark plug such that a breakdown voltage of said spark plug is exceeded and a linearly increasing current is developed across the electrodes of said spark plug; and
- firing angle control means coupled to said controlled high frequency switching means and said transformer means for controlling the timing of generation of said high frequency linearly increasing current between the electrodes of said spark plug.
- 2. A high voltage generating circuit according to claim 1, wherein said current control circuit comprises:
- a transformer having a primary winding and a secondary winding, wherein one side of said primary and secondary windings are commonly connected to said power supply;
- a first diode having an anode connected to another side of said primary winding and a cathode connected to said switching means; and
- a second diode connected in series between ground and another side of said secondary winding.
- 3. A high voltage generating circuit according to claim 1, wherein said switching means comprises:
- a power switch having an input connected to said current control circuit, an output connected to said transformer means and a control input;
- a transformer having a primary winding and a secondary winding, said secondary winding coupled to the control input of said power switch;
- a drive circuit connected to the primary winding of said transformer; and
- a gated oscillator having an output connected to said drive circuit and an input connected to said firing angle control circuit, wherein application of a signal from said firing angle control circuit to the input of said oscillator produces ON and OFF switching of said power switch.
- 4. A high voltage generating circuit according to claim 2, wherein said switching circuit comprises:
- a power switch having a source connected to said current control circuit, a drain connected to said transformer means and a gate;
- a transformer having a primary winding and a secondary winding, said second winding coupled between the gate and drain of said power switch;
- a drive circuit connected to the primary winding of said transformer; and
- a gated oscillator having an output connected to said drive circuit and an input connected to said firing angle control circuit, wherein application of a signal from said firing angle control circuit to the input of said oscillator produces ON and OFF switching of said power switch.
- 5. A high voltage generating circuit according to claim 1, adapted for use in an automotive ignition system including plural spark plugs, wherein said transformer means comprises:
- plural ignition transformers, each having a primary winding having one end connected to said switching means and a secondary winding having one end adapted to be connected to a respective spark plug and another end connected to ground, said primary winding of each said ignition transformer having an other end;
- plural ignition selection switching circuits connected to the other end of respective of said primary windings of said ignition transformers, each ignition selection switching circuit having an input coupled to said firing angle control circuit, said firing angle control circuit selecting a selected spark plug for ignition by applying an ignition signal to a respective ignition selection switching circuit.
- 6. A high voltage generating circuit according to claim 2, adapted for use in an automotive ignition system including plural spark plugs, wherein said transformer means comprises:
- plural ignition transformers, each having a primary winding having one end connected to said switching means and a secondary winding having one end adapted to be connected to a respective spark plug and another end connected to ground, said primary winding of each said ignition transformer having an other end;
- plural ignition selection switching circuits connected to the other end of respective of said primary windings of said ignition transformers, each ignition selection switching circuit having an input coupled to said firing angle control circuit, said firing angle control circuit selecting a selected spark plug for ignition by applying an ignition signal to a respective ignition selection switching circuit.
- 7. A high voltage generating circuit according to claim 3, adapted for use in an automotive ignition system including plural spark plugs, wherein said transformer means comprises:
- plural ignition transformers, each having a primary winding having one end connected to said switching means and a secondary winding having one end adapted to be connected to a respective spark plug and another end connected to ground, said primary winding of each said ignition transformer having an other end;
- plural ignition selection switching circuits connected to the other end of respective of said primary windings of said ignition transformers, each ignition selection switching circuit having an input coupled to said firing angle control circuit, said firing angle control circuit selecting a selected spark plug for ignition by applying an ignition signal to a respective ignition selection switching circuit.
- 8. A high voltage generating circuit according to claim 1, wherein said power supply comprises:
- a DC-DC converter having an input adapted to be connected to an automotive battery and an output connected to said current control circuit, said DC-DC converter provided to step up the voltage of said automotive battery for application of said stepped up voltage to said current control circuit.
- 9. A high voltage generating circuit according to claim 2, wherein said power supply comprises:
- a DC-DC converter having an input adapted to be connected to an automotive battery and an output connected to said current control circuit, said DC-DC converter provided to step up the voltage of said automotive battery for application of said stepped up voltage to said current control circuit.
- 10. A high voltage generating circuit according to claim 3, wherein said power supply comprises:
- a DC-DC converter having an input adapted to be connected to an automotive battery and an output connected to said current control circuit, said DC-DC converter provided to step up the voltage of said automotive battery for application of said stepped up voltage to said current control circuit.
- 11. A high voltage generating circuit according to claim 4, wherein said power supply comprises:
- a DC-DC converter having an input adapted to be connected to an automotive battery and an output connected to said current control circuit, said DC-DC converter provided to step up the voltage of said automotive battery for application of said stepped up voltage to said current control circuit.
- 12. A high voltage generating circuit according to claim 5, wherein said power supply comprises:
- a DC-DC converter having an input adapted to be connected to an automotive battery and an output connected to said current control circuit, said DC-DC converter provided to step up the voltage of said automotive battery for application of said stepped up voltage to said current control circuit.
- 13. A high voltage generating circuit according to claim 6, wherein said power supply comprises:
- a DC-DC converter having an input adapted to be connected to an automotive battery and an output connected to said current control circuit, said DC-DC converter provided to step up the voltage of said automotive battery for application of said stepped up voltage to said current control circuit.
- 14. A high voltage generating circuit according to claim 7, wherein said power supply comprises:
- a DC-DC converter having an input adapted to be connected to an automotive battery and an output connected to said current control circuit, said DC-DC converter provided to step up the voltage of said automotive battery for application of said stepped up voltage to said current control circuit.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Pat. application Ser. No. 268,889 filed June 1, 1981 now Pat. No. 4,382,430, and U.S. Pat. application Ser. No. 383,607 filed June 1, 1982.
US Referenced Citations (8)
Related Publications (1)
|
Number |
Date |
Country |
|
268889 |
Jun 1981 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
383607 |
Jun 1982 |
|