| 摘要 |
PURPOSE:To hold the protection of an output switching element and the reliabili ty by making the start characteristics in the transient state gentle and obtain facilitation and accuracy by reducing restrictions on the circuit design. CONSTITUTION:One AC input terminal of a rectifying circuit 1 is connected to one end of an AC power source E of the commercial frequency through a power supply switch S1, and the other AC input terminal is connected to the other end. A series circuit consisting of a ringing choke coil T1 of a converter transformer CT and the collector and the emitter of an output switching transisot (TR)Q1 is connected between output terminals of this rectifying circuit 1 through a smoothing capacitor 2. A pulse width control circuit 4 is connected to the bias circuit of the TR Q1 through a full-wave rectifying circuit 3, and the output terminal of this pulse width control circuit 4 is connected to the ringing choke circuit throug a differential amplifier 5 and an output pulse width controlling resistance R4. |
