Electric starting motor control system

摘要

A starting system for cranking an internal combustion engine that has a starter that is comprised of a solenoid and an electric cranking motor. The solenoid has pull-in and hold-in coils which when energized cause a pinion gear to be shifted into mesh with the ring gear of the engine to be cranked. Energization of the coils is controlled by at lest one N-channel field effect transistor which has its source connected to the negative terminal of a direct voltage source. A start switch is connected between the positive terminal of the voltage source and the gate of the transistor. When the start switch is closed the transistor is biased conductive to energize the pull-in and hold-in coils. The system may include a plurality of parallel connected N-channel transistors. The system inhibits turn-on of the transistor in the event that an excessive voltage is applied to the system. The system has transient voltage protection features.