Electronic ignition control system

A firing circuit in an ignition control system responsive to an electrical signal from a mechanical-to-electrical transducer and providing a control voltage to an ignition transformer generating a trigger voltage to a spark source, comprising in combination:

• a multiple stage pulse width amplifier having an input transistor, a second stage transistor and an output transistor;
• a voltage divider network of a first resistor in series with a second resistor for establishing a voltage level at the resistor interconnection;
• a coupling capacitor interconnecting the output of the input transistor to the input of the second stage transistor;
• a diode having an anode connection to said coupling capacitor and a cathode terminal interconnected to the junction of the resistors of said divider network;
• a first feedback network from the collector electrode of the second stage transistor to the base electrode of the input transistor;
• a second feedback network connected from a collector electrode of the output transistor to the collector electrode of the input transistor;
• a capacitor filter connected between the collector and base electrodes of the input transistor;
• and
• an output driver including a semiconductor amplifier connected to the output transistor and providing a control voltage to the ignition transformer.

A firing circuit in an ignition control system responsive to an electrical signal from a mechanical-to-electrical transducer and providing a control voltage to an ignition transformer generating a trigger voltage to a spark source, comprising in combination:

• a multiple stage pulse width amplifier having an input transistor and an output transistor;
• a capacitor filter connected between the collector and base electrodes of the input transistor;
• an output driver including a semiconductor amplifier connected to the output transistor and providing a control voltage to the ignition transformer;
• and
• a clamping circuit including a voltage dependent, symmetrical resistor that changes impedance when exposed to a high energy voltage connected across said semiconductor amplifier to provide overvoltage protection for said semiconductor amplifier.

A firing circuit in an ignition control system responsive to an electrical signal from a mechanical-to-electrical transducer and providing a control voltage to an ignition transformer generating a trigger voltage to a spark source, comprising in combination:

• a multiple stage pulse width amplifier having an input transistor, a second stage transistor, and an output transistor;
• a feedback network connected from the collector electrode of the output transistor to the collector electrode of the input transistor;
• a capacitor filter connected between the collector and the base electrodes of the input transistor;
• an output driver including a semiconductor amplifier connected to the output transistor and providing a control voltage to the ignition transformer;
• and
• a clamping circuit including a voltage dependent, symmetrical resistor that changes impedance when exposed to a high energy voltage connected across the semiconductor amplifier to provide overvoltage protection for said amplifier.

A firing circuit in an ignition control system responsive to an electrical signal of a mechanical-to-electrical transducer and providing a control voltage to an ignition transformer generating a trigger voltage to a spark source, comprising in combination:

• a pick-up as a part of the mechanical-to-electrical transducer and including a light emitting diode generating energy to a photo transistor;
• a multiple stage pulse width amplifier having an input transistor and an output transistor;
• a voltage divider network of a first resistor interconnected to a second resistor with the interconnection to the base electrode of the input transistor and the first resistor connected to the photo transistor of said pick-up;
• a feedback network connected from the collector electrode of the output transistor to the collector electrode of the input transistor;
• an output driver including a semiconductor amplifier connected to the output transistor and providing a control voltage to the ignition transformer;
• and
• a diode coupling between the output transistor and the input to said semiconductor amplifier.