| 摘要 |
<p>The power pack has a modulator stage for control of the switching ratio, an output stage with a transformer and a control stage which generates a control variable in accordance with the output voltage. A switching circuit (1) derives an interference variable following fluctuations of the rectified input voltage (U1), which controls a first voltage applied to a first input of a differential amplifier in the modulator stage (2). A second voltage is applied to its second input, controlled by the control variable. A constant, time depending voltage is applied to one of the amplifier inputs and the keying ratio of the differential amplifier output voltage is determined by the voltage difference at its two inputs.</p> |
