Anyone running a battery-powered project knows how frustrating it can be when a battery dies or runs too low to prevent brown-out conditions. The Uh-Oh Battery Level Indicator Kit can help prevent ...

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 ...