Capacitive-discharge system for internal combustion engines

Claim 2

In a capacitive-discharge system for internal combustion engines comprising a stepup transformer having primary and secondary windings, a capacitor in series with the primary winding, a DC power source to charge the capacitor, discharge means including a controlled rectifier to discharge the capacitor through the primary winding in timed sequence with an operating engine to induce a voltage in the secondary winding sufficient to fire a spark plug, pulse-producing means, a first transistor coupled between said pulse-producing means and the gate of said controlled rectifier for biasing the controlled rectifier to conduct in timed sequence with an operating engine, a diode between the output of the first transistor and said gate, said diode conducting only when a minimum predetermined voltage is applied thereto, said first transistor being valued to provide the necessary voltage when it is biased to conduct, and a second transistor connected between the output of the first transistor and ground, means biasing the second transistor to a conducting state when the first transistor is not biased to conduct by a signal from the pulse-producing means and to a nonconducting state when the first transistor is biased to conduct by a signal from the pulse-producing means.

Claim 3

A capacitive-discharge system as defined in claim 1, and further characterized in that said pulse-producing means includes a one-shot circuit, said one-shot circuit comprising third and fourth transistors cross-coupled by means including a capacitor for translating input pulses to a square wave signal, said first transistor being connected to the collector-emitter circuit of said fourth transistor and biased to conduct when said third transistor conducts, said second transistor being connected between said third and fourth transistors and biased to conduct when said fourth transistor conducts.

Claim 4

In a capacitor-discharge system for internal combustion engines comprising a stepup transformer having primary and secondary windings, a first capacitor in series with the primary winding, a DC voltage amplifier including an oscillator, a second capacitor connected to the output of the amplifier to be charged thereby, a resistor in parallel with said capacitor, said resistor providing a discharge path for the capacitor during operation of the amplifier under no-load conditions, the output of said DC power source being connected to said first capacitor to charge said first capacitor, discharge means to discharge the first capacitor to the primary winding in timed sequence with an operating engine to induce a voltage in the secondary winding sufficient to fire a spark plug, pulse producing means, a first transistor coupled between said pulse producing means and the discharge means for actuating said discharge means, a voltage device between the output of the first transistor and said discharge means, said voltage device conducting only when a minimum predetermined voltage is applied thereto, said first transistor being valued to provide the necessary voltage when biased to a conducting state, and a second transistor connected between the output of the first transistor and ground, means biasing the second transistor to a conducting state when the first transistor is not biased to conduct by a signal from the pulse-producing means, and to a nonconducting state when the first transistor is biased to conduct by a signal from the pulse-producing means, and an inductor in series with said second capacitor, said inductor being located between said first and second capacitors and functioning, along with said second capacitor, to prevent a full short across the voltage amplifier during discharge of said first capacitOr.

Claim 5

In a capacitor-discharge system for internal combustion engines comprising a stepup transformer having primary and secondary windings, a first capacitor in series with the primary winding, a DC voltage amplifier including an oscillator, a second capacitor connected to the output of the amplifier to be charged thereby, a resistor in parallel with said capacitor, said resistor providing a discharge path for the capacitor during operation of the amplifier under no-load conditions, the output of said DC power source being connected to said first capacitor to charge said first capacitor, discharge means to discharge the first capacitor to the primary winding in timed sequence with an operating engine to induce a voltage in the secondary winding sufficient to fire a spark plug, pulse producing means, a first transistor coupled between said pulse producing means and the discharge means for actuating said discharge means, a voltage device between the output of the first transistor and said discharge means, said voltage device conducting only when a minimum predetermined voltage is applied thereto, said first transistor being valued to provide the necessary voltage when biased to a conducting state, and a second transistor connected between the output of the first transistor and ground, means biasing the second transistor to a conducting state when the first transistor is not biased to conduct by a signal from the pulse-producing means, and to a nonconducting state when the first transistor is biased to conduct by a signal from the pulse-producing means, and an inductor in series with said second capacitor, said inductor being located between said first and second capacitors and functioning, along with said second capacitor, to prevent a full short across the voltage amplifier during discharge of said first capacitOr.