| 摘要 |
PURPOSE:To simplify a circuit and to miniaturize a high frequency transformer, by using the detecting voltage set up from a self-exciting winding for turning OFF. CONSTITUTION:An alternating rectangular-wave current generated by turning on and off DC voltage 1-1' with a switching transistor TR 3 is supplied to the input winding 2A of a transformer 2 for self-oscillation. The AC output of the winding 2C is rectified 13 and smoothed 14 to output DC voltage 15-15'. A series circuit of a diode 11 and a smoothing capacitor 12 is connected in parallel to a base control winding 2B, with which the voltage is taken out proportional to the output voltage. The charge in the smoothing capacitor 12 is caused to flow from emitter to base of TR 3 through TR 4 and TR 5 connected with thyristors and the accumulated carrier when the TR 3 was ON is quickly drawn to shorten the time until it is turned OFF. The circuit is thereby simplified and the loss in turning OFF is reduced accordingly.
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