Abstract: There are provided a first switch which is switched to the on state or the off state in association with a displacement of an actuator which causes a displacement by a contact with an object and a second switch which is switched to the on state or off state later than the first switch in association with the displacement of the actuator. A switch output is produced and an abnormality is detected in accordance with the on and off states of these switches.

Abstract: In a switching regulator including a pulse-width modulator for controlling the pulse width of a base input applied to a pair of transistors which are alternately turned on and off by the base input, the pulse-width modulator is provided, by an error amplifier, with an input corresponding to the magnitude of a detected output voltage, and variations in the input applied to the pulse-width modulator for increasing the pulse-width of the aforementioned base input are moderated by means of a time-constant circuit and a circuit for causing the time-constant circuit to be charged and discharged.

Abstract: A power control circuit is disclosed which may comprise a transformer having a primary winding and at least one secondary winding, a first and a second series circuit, and a rectifier circuit. The first series circuit may include a first DC power source, a first transistor and the primary winding of the transformer. The second series circuit may include the primary winding of the transformer, an excitation coil arranged to flow through the primary winding of the transformer a current which increases with time, a second DC power source and a second transistor. The rectifier circuit may be connected with the secondary winding of the transformer. In this power control circuit, an excitation current is first caused to flow through the primary winding of the transformer so that energy is stored therein.