| 摘要 |
PROBLEM TO BE SOLVED: To prevent the output current from sustaining overcurrent state. SOLUTION: The power supply unit comprises a power supply drive circuit 8, a transformer 9 having a primary winding 9A connected with the output portion 8A in the power supply drive circuit 8; an output terminal 10 connected with the secondary winding 9B of the transformer 9; a current detection resistor 11 interposed between one end of the output terminal 10 and one end of the secondary winding 9B; a comparator 12, having an input end 12A connected to one end of the current detection resistor 11 and an input end 12B connected to the other end of the current detection resistor 11; and a reference voltage generating circuit 13, interposed between the input end 12A or 12B and the current detection resistor 11 where the output signal from the comparator 12 is fed back to the power supply drive circuit 8, the transformer 9 is provided with an auxiliary winding 9C, the auxiliary winding 9C and a power supply section 12D of the comparator 12 are connected by a power supply line 100, and the power supply line 100 is not connected directly to the output terminal 10. COPYRIGHT: (C)2008,JPO&INPIT
|
