| 摘要 |
A stabilized high voltage power supply circuit for a cathode-ray tube using electromagnetic deflection. The secondary coil of a transformer for high voltage controlling is connected with the primary coil of a flyback transformer. Further, a control circuit is provided to be connected with the primary coil of the high voltage controlling transformer. The control circuit comprises an operational amplifier which outputs a DC voltage corresponding to the difference between a feedback voltage proportioned to the high voltage output and a predetermined reference voltage, a first transistor whose base receives a rectangular wave voltage generated across the primary coil of the high voltage controlling transformer for controlling the high voltage and whose emitter is connected with the output of the operational amplifier, and a second transistor which controls the primary coil current of the high voltage controlling transformer according to the on/off of the first transistor. The control circuit controls the peak value of the pulse current generated in the secondary coil of the high voltage contrrolling transformer by controlling the primary coil current of the high voltage controlling transformer according to the change of the high voltage output. Then, the control circuit attains the stabilization of the high voltage output by superimposing this pulse having the controlled peak value on the pulse in the primary coil of the flyback transformer so that the high voltage output level is kept constant. |
