Skidding vehicle speed detector - has circuit producing error signal to denote open circuit fault condition

摘要

A detector circuit is connected to antiskid and antislip equipments in order to transmit their speed. The detector output provides a signal representing the rotational condition of the wheels and the detector is able to signal faults within the detector or cabling. A detector comprises two field plates resistances (1,2) operating in conjunction with toothed wheels and connected in series in the emitter circuit of a transistor (4) whose base has a constant potential applied to it so that the signal is independent of power supply variations. The detector output (9) is applied to an amplifier (11) which is activated via a resistor (18) and decoupling diode (16) in the event of an open circuit in the field plate circuit. This effect produces an error signal for a difference amplifier (27) whose output drives a lamp (49) indicator via a decoupling diode (46).