PUSH CURRENT INHIBITION CIRCUIT FOR SWITCHING REGULATOR POWER SOURCE

摘要

PURPOSE:To enhance resistance to noise, by providing a relay having a constant open contact in place of a resistance in a snubber circuit, and by providing this constant open contact side by side to a current limiting resistance. CONSTITUTION:A switching regulator power source is equipped with a DC power source 1, a transformer 3, a main current circuit 4, a control circuit 5 and an output circuit 6, and has got a rush current inhibition circuit 2. This rush current inhibition circuit 2 is formed by replacing the coil of a relay 12 having a normally open contact 12a with the conventional resistance in a snubber circuit 7. Thus, when the current to the primary coil 3a of a transformer 3 is cut off, the voltage induced to this primary coil 3a charges a capacitor 18 through a diode 19 and at the same time it causes to flow the current to the coil of the relay 12 for actuation. Through the relay 12 the charge on this capacitor 18 can hence be discharged and the actuation to suck continued.