| 摘要 |
PURPOSE:To obtain a small-sized circuit by composing a serial control circuit of two transistors (TR) with high dielectric strength while the emitter of one TR is connected to the collector of the other, and controlling base currents of both TRs. CONSTITUTION:An AC voltage Vi applied between terminal I1 and I2 is passed through the serial control circuit MC and a waveform shaping circuit WS to develop a stable AC voltage V0 between terminals O1 and O2. By a monitor voltage Vd obtained from a transformer T, a DC control voltage Vc is obtained from an auxiliary control circuit BC and applied to bases of the TRs Q6 and Q7 whose saturation values of collector currents of the TRs Q6 and Q7 are thus controlled. The TRs Q6 and Q7 use TRs with enough reverse dielectric strength to obtain tolerance to a reverse voltage applied when they turns off. Thus, a protecting diode is omitted and the size of the circuit is reduced to constitute the high-efficiency circuit. |
