JPH0447380U - - Google Patents

Description

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a waveform diagram of the above device. FIG. 3 is a circuit diagram of a conventional device, and FIG. 4 is a waveform diagram explaining the operation of this device. 10... Rush current limiting circuit, 12... Switch circuit, 14... Gate circuit, 20... Converter section.

Claims (1)

[Claim for Utility Model Registration] A rectifier circuit that rectifies alternating current, and a capacitor that stores the current output from the rectifier circuit via an inrush current limiting circuit, and the current stored in the capacitor is transferred to the converter section. In the output power supply device, the converter section includes a transformer having a primary winding, a secondary winding, and an auxiliary winding, the primary winding connected to the capacitor, and a switching element connected to the primary winding. The inrush current limiting circuit includes a triax, a current limiting resistor connected in parallel with the triac, and a switch having a predetermined delay time τ provided between the auxiliary winding and the gate terminal of the triac. circuit, and a gate circuit that turns on the switch circuit when the alternating current is input and flowing, and the delay time is compared with the rise time T determined from the alternating current input voltage and the values of the power supply limiting resistor and capacitor. If the voltage stored in the capacitor is higher than the operation stop voltage Vstop of the converter section when the alternating current is turned on again at the time of a momentary interruption of the alternating current, the switch circuit is set to have a try-on voltage of τ<T. An inrush current prevention circuit for a power supply device, characterized in that the timing of turning on is delayed by a predetermined delay time from when turning on again.