Excitation circuit for an alternator especially for motor vehicles and controller with an alternator containing it

摘要

The field winding (Ex), earthed at one end, is connected to the alternator terminal (B+) via an MOS transistor (Tex) giving the voltage regulator field current control. An engine control unit (CCM) connection (C) is plugged (FR) into an inverter circuit (I) connected across the field coil. This employs two MOSTs(T1,T2) forming a current mirror. When the field control transistor(Tex) is conducting, a resistance(Ri) limits the current through the first mirror MOST(Tl) to, e.g. lmA., The mirror output current, a multiple of this, e.g. 40mA, passes to the engine controller lead (C), which is connected to the ignition positive(+cle) by a pull-up resistor (R1). Zener diodes (XZ,DZ1) provide protection against electrostatic discharges. An IC approach to circuit construction is described.