| 摘要 |
A converter is provided in which the cost and size of which are reduced by a decrease in current consumption with no need of large elements or radiation fins. The converter has a switching element (Q 1 ) being connected to a DC power source through a primary winding (P) of a transformer (T), a control circuit ( 4 ) for turning on/off the switching element (Q 1 ), a diode (D 51 ) and a capacitor (C 51 ) for rectifying/smoothing the voltage induced in the secondary winding (S) of the transformer (T) to extract DC output, and a starting circuit ( 5 ) for starting the control circuit ( 4 ). The starting circuit ( 5 ) operates as a constant current circuit (Q 2 , R 1 , R 2 , ZD 1 , D 1 ) while starting the control circuit ( 4 ), and as a constant voltage circuit (Q 2 , R 1 , R 2 , ZD 2 , D 1 ) after starting the control circuits ( 4 ).
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