| 摘要 |
<p>A television apparatus has a horizontal deflection circuit (TP10) with a transformer (LP04) for developing a derived secondary power source. A circuit (TP01,TP02) for disabling the horizontal deflection circuit is responsive to a fault condition in the horizontal deflection circuit. A driver stage (Fig. 6) in a vertical deflection circuit is energized by the secondary power source (CP20) or supplying vertical deflection current to a vertical deflection yoke (BF01). An S-shaping capacitor (CF01) is coupled in series with the vertical yoke. A circuit for sensing vertical yoke current includes a sampling resistor (RF01) coupled in series with the vertical yoke and the S-shaping capacitor. The vertical yoke current sensing circuit generates a feedback signal for controlling the vertical deflection circuit during normal operation, and generates a fault signal indicative of an overcurrent condition in the vertical yoke. Indication of the overcurrent condition is calibrated to be indicative of fault conditions in the vertical driver stage and/or in the S-shaping capacitor. The disabling circuit is also responsive to the vertical yoke current sensing circuit for disabling operation of the horizontal deflection circuit, which in turn disables the secondary power source and the vertical driver stage. A diode (DF01) couples the vertical yoke current sensing circuit to the disabling circuit.</p> |
