| 摘要 |
PURPOSE:To remedy the alteration of a stepup transformer without regulation by controlling the transformer by driving an RS flip-flop on the basis of the detected value of the flyback voltage of the transformer at zero point passing time and a load current detection value. CONSTITUTION:In a power source circuit for supplying power generated at the secondary side of a step up transformer T to a load RL by interrupting by switching means Tr at the primary side of the transformer T, zero cross detecting means 1 for detecting the time when the flyback voltage of the transformer T passes a zero point is provided. Further, means 6 for controlling the voltage conversion efficiency by detecting the load current is provided, a time constant circuit 5 for rising by the output of an Rs flip-flop 3 is provided, and the output of efficiency control means 6 and the output of the circuit 5 are compared by comparing means 7. The output of the means 1 and the output of the means 7 are input to the RS flip-flop 3, and switching means Tr is driven by the output. |
