PURPOSE: To certainly enable the stoppage of load drive even when the voltage of a battery is lowered, by such simple constitution that a load driving transistor is controlled through a diode connected to a load drive stopping switch.

CONSTITUTION: A diode D is connected between a load drive stopping switch S1 and a load driving transistor T2 and, when the switch S1 is closed, a current is flowed through the switch S1, the diode D, a resistor R2 and a transistor T1 to control the base current of the transistor T2. In this case, a current flowing to an alarm sound generating apparatus AL through the transistor T2 is reduced and the sounding stoppage of the alarm sound of the load is certainly performed even if oscillation is stopped by the voltage falling of a battery E and the generation of alarm output from a clock integrated circuit A succeeds.