the invention relates to a method and a device for setting a timer circuit , especially in a fuse , there being used a setting unit for the transfer of setting signal to the timer circuit which is housed in the fuse . for the purpose of simplifying the communication between the fuse and the fuse setting unit , both as regards to avoiding previous calibration of the timer reference of the system , and as regards a reduction of the electro - mechanical contact connection between the fuse and the setting unit to a minimum , it has according to the invention been suggested that there are provided setting signals such that the time to which the timer circuit is to be set , is transferred from the setting unit to the fuse by pulse width modulation of the power supply voltage . the setting signal can then be transferred via only two contacts on the surface of the fuse . the modulation can be to the fact of increasing the power supply voltage from a certain first value to a higher value and back to the first value .