| 摘要 |
PROBLEM TO BE SOLVED: To reduce the stand-by power of a switching regulator. SOLUTION: In the switching regulator, a first resistor, a photocoupler diode, and an electronic switch for controlling the photocoupler according to a stand-by signal are connected in series between a (+) output terminal and a (-) output terminal of the switching regulator. An emitter of the transistor of the photocoupler of the primary side and a second resistor are connected to the base of an NPN transistor, and a collector of the NPN transistor is connected to a feedback terminal (FB) of an IC for controlling the switching regulator. Thus, while the stand-by signal is applied to the electronic switch, except when a full-wave rectified voltage is near 0V, the power source is stopped to set the switching loss to '0', thereby reducing the stand-by power.
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