| 摘要 |
PURPOSE:To reduce the size and cost of a DC-DC converter while the energy efficiency of the converter is improved. CONSTITUTION:A DC-DC converter circuit 1 is composed of first and second oscillation circuits 3 and 4 which are connected to the primary winding 12a of an oscillatory transformer 12, switching circuit 5, etc. The primary winding 12a of the transformer 12 is equipped with a terminal A having a number of turns N1A and another terminal B having another number of turns N1B (N1A>N1B). When the DC voltage applied across the winding 12a from a battery 9 is switched by means of the first or second oscillation circuit 3 or 4, boosted power is induced in a secondary winding 12b and a charging current which is rectified through a rectifying diode D1 is supplied from an output terminal 20. The switching circuit 5 is composed of a detecting section 51 and switching section 52 and, when the voltage at a main capacitor 10 exceeds a prescribed level, the oscillation circuit connected to the winding 12a is switched to the circuit 4 from the circuit 3. |
