| 摘要 |
PURPOSE:To make an inverter circuit to operate stably from the quasi-E class mode up to the feed forward mode by a method wherein a power switching semiconductor is made to conduct when the voltage of the power switching semiconductor is zero or the lowest voltage. CONSTITUTION:An AC voltage is applied to a rectifying circuit 2 from an AC electric power source 1, and is converted into a DC voltage to constitute a DC electric power source. The inverter circuit 3 is connected to a DC output terminal of the rectifying circuit 2, and the inverter circuit 3 is controlled by a control circuit 4. The control circuit 4 contains a pulse duration control circuit 42 to control conducting pulse duration of the power switching semiconductor 32 synchronizing with the output signal of a zero point detecting circuit 41 to detect the zero point of a current signal sent from a current transformer 40 to detect the current of a capacitor 34 for resonance, and a driving circuit 43 to control the power switching semiconductor 32 corresponding to an output signal thereof. |
