Vehicle supply state monitor - has diode ensuring differential voltage drop across charge lamp during over-excitation period

摘要

Various defects of a transistor controller of a vehicle supply unit are readily detected preventing damage of inboard battery by voltage rise in the case of its short-circuit. The charge indicating lamp (11) is connected to a Zener diode (18) maintaining a constant voltage. Over-excitation leading to a rise in the inboard supply voltage causes a differential voltage drop across the lamp. The lamp (11) is connected to the positive terminal of the inboard supply via ignition switch (10) while a junction (12) connects it to the battery (6). The junction also links the excitation winding (9) of the alternator (1) while the other terminal of the lamp is connected to a decoupling diode (13).