| 摘要 |
<p>HIGH VOLTAGE PROTECTION CIRCUIT A horizontal deflection system driven auxiliary supply for a television receiver has as a rectifying device an integrated thyristor-rectifier (ITR). When the deflection system is operating under normal conditions, the rectifier portion of the ITR provides direct operating current through conventional filter circuitry to other receiver circuits, such as the vertical deflection system, whose performance is essential to the production of a viewable display. When the horizontal deflection system generates excessive voltage which results in an undesirable increase in the picture tube anode voltage derived from the deflection system, the peak cathode voltage of the rectifier portion, and thus the peak anode voltage of the thyristor portion of the ITR, rises. When the anode of the thyristor goes sufficiently positive with respect to its cathode, the voltage drop across the thyristor exceeds its breakover voltage and the thyristor begins to conduct heavily, removing the operating current from the other receiver circuits and rendering the display unviewable.</p> |
