IC engine starter motor circuit - has NTC resistor in series with starter relay for controlled engagement of pinion

摘要

The starter motor (23) is operated by a relay (22) with temperature independent control. This is achieved by a series connected NTC resistor (20) in the relay coil circuit. The voltage applied to the relay coil is constant over a temperature range and ensures that the relay moves the starter pinion into mesh at a controlled rate, before the starter motor is activated. The characteristics of the NTC resistor are selected to counteract the resistance changes in the coil due to thermal variations. The NTC resistor operates from -30 deg.C to 160 deg.C. ADVANTAGE - Even engagement of starter pinion, less starter noise, less starter wear.