Isn’t it always the way? There’s a circuit right out of the textbooks, or even a chip designed to do exactly what you want — almost exactly. It’s 80% perfect for your application, and rather than ...

Signals when an on-circuit battery is exhausted, 5V to 12V operating voltage A Battery-status Indicator circuit can be useful, mainly to monitor portable Test-gear instruments and similar devices. LED ...

D1 is the voltage reference zener. Tied to this is a string of divider resistors (R2-6) that set the various fixed voltage levels. R7 & 8 form a voltage divider to that divides the battery voltage by ...