Abstract: An automatic replacement circuit is provided for the replacement of burnt-out filaments as well as a method for implementing the replacement of incandescent filaments. The replacement circuit includes a pulse generator which operates independently of the activated filament to feed continuous feed pulses to a counter circuit while a separate resetting pulse circuit delivers resetting pulses to the counter unit in dependence on the current flowing through the filament. The resetting pulses cancel the feed pulses. In the absence of resetting pulses, the feed pulses accumulate and upon reaching a predetermined amount, trigger a trigger selector circuit for activating the next filament.