| 摘要 |
PURPOSE:To remedy the alteration of a stepup transformer without regulation by controlling the transformer by driving a time constant circuit 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 3 for controlling the voltage conversion efficiency by detecting the load current is provided, and the output is compared with the output of a time constant circuit 2 by comparator 4. The output of the means 1 and the output of the means 4 are input to the circuit 2, and the TR is controlled by the comparison output f. |
