| 摘要 |
PURPOSE:To prevent a circuit element from damaging by directly switching a switching transistor by a flyback pulse, thereby simplifying a power source. CONSTITUTION:A starting resistor 12 is connected between the collector and the emitter of a switching transistor 5, and a resistor 13 is connected between the emitter and the base. A resistor 14 and a Zener diode 15 are connected in series between the base and a ground point, and a capacitor 16 which forms an integrator together with the resistor 14 is provided. When a nonstabilized DC voltage is applied to an input terminal 1, a TV set 7 starts operating, a flyback pulse is applied from a terminal 9 through a resistor 17 to the diode 15, and stabilized to obtain a saw-tooth wave voltage by the integrators 14, 16. This voltage is applied to the base of the transistor 4 to alter the energizing duty ratio, thereby suppressing the variation in the output power of the stabilized power source. |
