Low-Battery Indicator

Posted on Feb 3, 2013

The sensing circuit consists of a 741 op amp set up as a voltage comparator, using a zener diode as a voltage referen

Low-Battery Indicator
Click here to download the full size of the above Circuit.

ce. The op amp is inserted as a bridge between two resistance ladders, one which contains the zener reference, and the other a high-value linear potentiometer. When the voltage at the wiper of the potentiometer drops below the voltage set by the zener, the output of the op amp becomes low; that turns on the LED connected between it and Vcc- The circuit can be adapted to work with battery-powered circuits that require between 6 and 18 V; the only changes needed would be a lower-voltage zener and a smaller current-limiting resistor in the case of voltage below 9 V, and a larger resistor for higher voltages.

Leave Comment

characters left:

New Circuits



Popular Circuits

Voltage Test Probe
Infrared Remote Control Jammer circuit
Clock using analogue multimeters ( PIC16F628A )
Highly Stable 60Hz Sine-Wave Source Circuit
Atari 2600 CE
mini mosfet audio amplifier
Accident Prevention and Security System for Automobiles