Voltage monitor which applies clock pulses - is coupled to reference voltage at operational amplifier input to detect tolerance deviations

摘要

The voltage monitor checks the upper and lower tolerance limits of a voltage using an ac signal or a clock signal. This is achieved by applying the voltage (U) to be monitored between OV and the non-inverting input of an operational amplifier (2). A reference voltage (UR) is applied via a resistor (7) and two antiparallel diodes (4,5) to the inverting input. The clock signal (+ DELTAU) is used as bias voltage for the diodes and is applied to them via a dc blocking capacitor (6). The sign of the output voltage (UA) depends on whether the input voltage exceeds or falls below the reference. Potentiometers can be used to set the tolerance range and the reference independently.