PURPOSE: To reduce the accumulation effect of a charge due to the current of a transistor (TR) which charges and discharges a capacitor and turn of the TR in a short time by providing a current absorbing means which absorbs the charge accumulated at the base of the TR when the TR turns off to the base of the TR.

CONSTITUTION: A discharging TR18 is connected through a TR22 to the output side of an FF16 which operates with the outputs of the 1st and the 2nd voltage comparators of a timer circuit, and the current absorbing TR26 is connected between the base of the TR18 and the ground 2. A resistance 27 is connected between the base of the TR26 and a power source terminal 1 and a diode 28 is connected between the base of the TR26 and the ground 2. The current absorbing means consists of the TR26, resistance 27, and a diode 28. When the TR18 turns off, the charge accumulated at the base of the TR18 is absorbed by the current absorbing means to reduce the accumulation effect of the charge due to the current of the TR18, turning off the TR18 in a short time.