Abstract: A control system for the carburetor of an internal combustion engine wherein the carburetor has a choke valve disposed at the inlet of the carburetor induction tube and the choke valve is operated automatically by an actuator. The actuator for the control includes a pulse-width modulator in which the pulse width or the degree of modulation is influenced by a family of characteristics stored in a programmable memory, the memory applying signals to the pulse-width modulator for pre-specified air-fuel mixtures in accordance with engine speed.

Abstract: Capacitor ignition systems for internal combustion engines in which a charging winding forms part of an ignition coil and a primary winding is connected in circuit with the charging winding to contribute to capacitor charging. In one embodiment, the secondary winding is also connected in circuit with the charging winding which contributes to development of an output voltage. Circuit components are provided for insuring a high output voltage while protecting a charging diode against excessive inverse voltage during ignition and for protecting the gate of a thyristor switch from an excessive negative voltage.