Variable voltage maximum and minimum detection system - has transistor connected in series with resistor and operational amplifier

摘要

The device described detects the maximum and minimum values of a variable electrical voltage. It comprises a transistor connected in series with a resistance to a d.c. supply, together with a system which takes the base of the transistor to a voltage which switches off the transistor or, on the contrary, makes it conducting, when the variable electrical voltage has just passed through a maximum or a minimum. The system which varies the voltage applied to the base of the transistor comprises an operational amplifier whose two inputs are connected to one of the poles of the variable voltage via diodes or equivalent devices. The output of the amplifier is connected to the base of the transistor. One of its inputs is connected also through a capacitor to one of the poles of the voltage supply.