| 摘要 |
PURPOSE:To stably convert voltage in a power supply device by controlling the circuits for a commercial power supply device consisting of a rectifying circuit, parallel resonant circuit, transformer, etc. by employing astable multivibtators. CONSTITUTION:A voltage from a commercial AC power supply 31 is applied to a rectifying circuit 32. The output from the circuit 32 is applied to a parallel resonant circuit consisting of a stabilizing choke coil L and a capacitor Cs and connected with a series circuit of the excitation coil N1 of a transformer 20 and a switching transistor Qd. At this time a switching diode Dd and a resonant capacitor Cd are connected in parallel with the collector and the emitter of the transistor Qd. As table multivibrator 33 is formed of transistors Qa and Qb. The pulse from the multivibrator 33 is supplied to the base of the transistor Qd through the transistor Qc. In addition, a control circuit 40 consisting of transistors Qe, Qf, Qg and a constant-voltage diode Dz is connected to the control coil Nc of the transformer 20 to control the operating voltage. |
