low battery indicator

[7102]

Hi,

I need a circuit for low battery indication my battery volatge is 24V.

if the voltage is 23V the led in the circuit has to OFF.

if the voltage is 21V the led has to switch ON.

please help.

thanks,
7102.

 

[BradtheRad]

This low-battery monitor has worked in simulation.

Schematic:



Values were selected so that (a) led cannot be exposed to overmuch current, and (b) circuit uses 8 mA or less when the led is off.