Supply voltage monitor
In much equipment, such as computers,
amplifiers, and the like, where high tolerance
components are used, it is important
to know at all times whether the supply
voltage is within specification. The circuit
presented here was designed to show just
that. It does so by eomparing two d.c. voltages.
As soon as there is a difference of
more than 10 mV between these. the indicator
LED goes out to signal that something
is amiss. lt is, therefore, neeessary to
use a very accurate reference voltage, corresponding to the required voltage level.