| 摘要 |
PURPOSE:To realize a small-sized, lightweight transformer for power source substantially widening a magnetic flux variation range up to induce the magnetic saturation, by applying a reverse bias previously in resopnse to sudden variations in magnetic flux accompanying with the conduction of a primary current. CONSTITUTION:A voltage induced in the secondary winding 1b of a transformer 1 is outputted through a rectifying circuit 4 and a smoothing circuit 5. The output voltage is fed back to a conduction phase angle control circuit 6 and a triac 2 controls the supply of AC input power. Control windings 1c and 1d, when the triac 2 is on, biase the magnetized state of an iron core 1h previously in the reverse direction. A control current supply circuit 10 supplies conctrol currents to the control windings 1c and 1d and detects the start of primary current supply by detecting that the output of a detection winding 1e has reached a prescribed level. Then, one-shot multivibrators 12 and 13, are operated to supply control currents. |
