Based on a 555, this 80's American documentation circuit detects the voltage of a battery and can then disconnect the charger. The transistor may be a general purpose type.
This circuit was found in a 90s EDN. Its purpose is to increase the efficiency of operational...
This circuit is used to match a high impedance input source with a low impedance output device...
This is an improved version of the previous circuit also found in the December 1990 Radio...