| 摘要 |
PURPOSE:To miniaturize a drive circuit section and also to prevent the retrigger of a transistor (TR) to be driven by connecting an N-ch FET in series to the emitter of the TR to be driven and driving the FET with an FET drive winding of a current transformer. CONSTITUTION:When the level of a control signal vc goes from H to L, a charge current flows to a capacitor 4 and also an input capacitance 14b of an FET14 is charged via an FET drive winding 9d, the FET14 is turned on and a TR12 is driven by a route of TR base winding 9b TR12 to be driven FET14 winding 9b at the same time. When the control signal vc goes from L to H, the capacitor 4 starts discharge. A positive bias is applied to a drive FET15 through an FET drive winding 9d to be turned on, the input capacitor is charged reversely and the FET14 is turned off. The off-operation of the TR12 is promoted by the stored energy of a current transformer 9 and the TR12 is led to be turned off forcibly by the turning-off of the FET14. The FET14 is reverse-biased at all times and turned off and then the retrigger of the TR12 is prevented. |
