Vehicle alternator voltage regulator - uses parasitic resistors in thick film circuit to counteract voltage fall

摘要

The technique of silk-screening thick-film layers on to a substrate is used to construct this vehicle alternator control circuit. A voltage sensing bridge (17, 19) with a thermistor (17a) controls a zener diode (14) which, in turn, controls a Darlington pair of transistors (21, 24). These are connected to the field windings and switch its current in a non-linear mode. Parasitic resistors in the thick-film conductors (31 to 34) are used to modify the action of the bridge and Darlington pair in order to counteract the effect of the inherent fall in alternator voltage as the output current increases.