| 摘要 |
PURPOSE:To shorten an accumulation time simply and economically by interposing an accumulated-charge absorption circuit composed of a transistor and diode between the base and emitter of a switching transistor. CONSTITUTION:When a pulse of waveform 1 is applied to point (a) at the secondary side of pulse transformer 1, a voltage current of waveforms 2 and 3 is generated at the base of switching transistor (Tr)7 via reverse-current preventive diode 4 and a collector current of waveform 4 starts flowing. At this time, accumulated- charge absorbing Tr3 is OFF and base resistance 2 operates to adjust the impedance at the secondary side of transformer 1 in this state. Although a reverse voltage of waveform 1 is developed at point (a) when a pulse at point (a) is OFF, Tr3 turns ON to absorb an excessive voltage stored in the base of Tr7. Then, (ts) and (ts') of waveform 2 show the comparison between the insertion of accumulated-charge absorption circuit 5 and non-insersion. Consequently, the number of parts is small and the circuit constitution is simple, so that this circuit will suit to high-density packing. |
