| 摘要 |
A standby power circuit provided when a power for control circuit (auxiliary power) controlling a main power switch circuit with the main power switch circuit turned off is turned on, wherein an AC power and a load circuit are connected in series to the main power switch circuit using, as contact terminals, both drains of two MOSFETs where gates and sources are connected to each other, respectively, and a resistor and a diode are connected in series to the parallel circuit of a zener diode and a capacitor from a source side between the connection point of the AC power load circuit and the source of both FETs, whereby the anode of the zener diode is located on the source side and the anode of the diode dislocated on the AC power load circuit side, a charging voltage of the capacitor becomes the power of the control circuit as an auxiliary power and, when the output of the control circuit is applied between the gates and between the sources of the MOSFETs of the main power switch circuit, the load circuit is turned on and off because both FETs are turned on and off by Hi/Low of the output from the control circuit, and then a standby power of this circuit is formed of a current flowing through a resistor and the standby power is determined by the resistance.
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