SWITCHING REGULATOR POWER SUPPLY DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce a rush current, while power loss increase caused by the decline in an input voltage is prevented. ;SOLUTION: A power thermistor 7 which suppresses a rush current applied to a smoothing capacitor 8, when a power supply is closed is connected in series between an output rectifying device 6 and the smoothing capacitor 8 of a step-up chopper circuit 100. Since the output voltage of the step-up chopper circuit 100 is controlled to be constant, it power is constant, the average value of an output current is controlled to be constant regardless of the input voltage, and the loss of the power thermistor 7 will not increase when the input voltage is low. Furthermore, by reducing the loss of the power thermistor 7, a power thermistor 7 with a larger resistance can be employed.;COPYRIGHT: (C)1999,JPO