simple supply voltage monitor

Posted on Feb 6, 2014

A circuit for monitoring supply voltages of ±5 V and ±12 V is readily constructed as shown in the diagram. It is appreciably simpler than the usual monitors that use comparators, and AND gates. The circuit is not intended to indicate the level of the inputs. In normal operation, transistors T1 and T3 must be seen as current sources. The drop acr

simple supply voltage monitor
Click here to download the full size of the above Circuit.

oss resistors R1 and R2 is 6. 3 V (12 5 0. 7). This means that the current is 6. 3mA and this flows through diode D1 when all four voltages are present. However, if for instance, the 5 V line fails, transistor T3 remains on but the base-emitter junction of T2 is no longer biased, so that this transistor is cut off. When this happens, there is no current through D which then goes out.

Leave Comment

characters left:

Related Circuits

  • New Circuits



    Popular Circuits

    Stereo Audio signal Isolator
    Lead Acid Battery Charger with LED indicator
    simple electronic organ
    Rotate a stepper motor using a computer
    make tv transmitter
    central locking interface
    SW RF Pre-Amplifier
    Arduino Running A DC Motor and High Current Lamp