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 indicator circuit used and game machines (arcades) to indicate that the machine is being...
This circuit fires at the touch of a sensor, passing its output from high to low in a time given by...
This circuit is from an English magazine from 1978. The circuit can be assembled with BC557, BC547...