| 摘要 |
In a video display monitor having a multiple rate scanning capability, a synchronized switching power supply develops the regulated operating voltages for the monitor. A deflection circuit produces scanning current in a deflection winding and is capable of being operated at either one of two selectable scanning frequencies. A signal synchronously related to the scanning current, such as a retrace pulse voltage, is applied to the control circuit of the switching power supply. The control circuit generates a control signal from the retrace pulse voltage that is synchronously related to the scanning current and of a frequency that is unchanged when the deflection circuit is operated at either of the two selectable scanning frequencies. The output stage of the switching power supply responds to the control signal and produces switching operation at the unchanged frequency in synchronism with the scanning current. |
