This circuit is from an August 1984 Radio Electronics magazine. It monitors the state of a RAM backup battery. Resistor R1 determines the battery charge.
This circuit was taken from Maxim documentation from the 1990s. It can be implemented on the basis...
This circuit allows linear brightness control of an LED from an input voltage. The power supply must...
This circuit is from a Hands-On Electronics from 1987, but it can still be easily assembled, as...