| 摘要 |
PROBLEM TO BE SOLVED: To improve efficiency by constituting a simple circuit where the number of parts is small, and also remove unnecessary converter loss, in a switching power unit which has a plurality of DC-DC converters. SOLUTION: AC from an AC power source 1 is rectified with a diode bridge 3, and the DC is supplied to the transformer 5b of a main converter and the transformer 5a of a subconverter. Then, the output is generated on the secondary side of a transformer, by turning on or turning off the main switching element 6b and the sub switching element 6a. Moreover, only the main converter is provided with an auxiliary power source 10 for a control circuit 11b, and the control circuit 11a of the subconverter is supplied with power via a switch circuit 12 from this auxiliary power source 10. The switching circuit 12 is controlled by the trigger circuit from the outside. |
