INSULATION TYPE SWITCHING POWER SUPPLY

摘要

An insulation type switching power supply has a capacitor for supplying a control power required for controlling the switching of a switch element, and a constant current supplying unit (14) for supplying a constant current. The insulation type switching power supply comprises: a first control unit (10) that controls the switching of the switch element; a switch unit (11) that short-circuits or open-circuits the first control unit (10) and the capacitor; a capacitance element unit that includes a capacitor (C4) the voltage across which varies in accordance with the output voltage in a standby mode and to which the constant current is supplied from the constant current supplying unit (14); and a second control unit (12) that controls the power-supplying of the first control unit (10) by short-circuiting or open-circuiting, in accordance with the voltage across the capacitor (C4), the switch unit (11) during a switching halt interval in the standby mode.