| 摘要 |
A deflection generator develops scanning current in a deflection winding and produces a deflection rate alternating polarity voltage at a deflection generator terminal. A first winding of an input transformer is coupled to a source of supply frequency alternating polarity voltage and to a regulator switch for transferring energy from the source to a load circuit coupled to another winding of the input transformer. A second winding is coupled to the deflection generator terminal. The conduction time of the regulator switch controls the amount of energy transferred. A regulator control circuit turns on the regulator switch at a controlled instant within a first polarity interval of the deflection rate alternating polarity voltage to draw current in the first winding from the source. The deflection rate alternating polarity voltage applied to the second winding is reflected to the first winding and commutates off the regulator switch during the alternate polarity interval of each deflection cycle. A signal representative of variations in a deflection circuit energy level is applied to the regulator control circuit and varies the conduction time of the switch to regulate the energy level. A second controllable switch is coupled in the series path of the input current from the source of supply frequency alternating polarity voltage. A second control circuit generates a second switch turn-on signal to enable the input current to flow. During the start-up interval prior to steady-state operation of the deflection circuit, the second switch turn-on signal is generated immediately prior to the zero-crossover instants of the supply frequency alternating polarity voltage. Subsequently, the second switch turn-on signal is phase advanced from the zero-crossover instant to permit normal regulated deflection circuit operation to commence.
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