| 摘要 |
The present invention relates to an electronic switched-mode power supply for powering an electrical consumer from an a.c. or d.c. source of variable voltage with a primarily pulsed blocking oscillator containing a transformer, the secondary winding of which is connected in series with the electrical consumer and to a first diode and the primary winding of which is connected in series to the collector-emitter path of a first transistor, the base of which is connected via a feedback capacitor to one end of the secondary winding of the transformer, where the base of the first transistor is also connected to one pole of the input voltage source. Several feedback capacitors are applied to the secondary winding of the transformer in the transformer discharge phase to act with a parallel connection effect and, in the transformer charging phase, are applied as a series circuit to a branch comprising the base-emitter path of the first transistor. The invention is suitable for use in an electric shaver. |
