| 摘要 |
PROBLEM TO BE SOLVED: To provide a deflection circuit for reducing effective fly-back capacitance. SOLUTION: A video display deflection device includes first and second fly-back capacitances. A deflection coil is combined with the first and second (fly-back) capacitance to form a resonance circuit in fly-back. The first switching transistor connected to the first capacitance generates the first fly- back pulse voltage in the first capacitance in response to the first control signal of a frequency related with a selected deflection frequency. The second switching transistor is connected to the second capacitance and generates the second fly-back pulse voltage in the second capacitance, in response to the second control signal having a variable phase with respect to the first control signal. The first and second fly-back pulse voltage is applied to a deflection coil to generate a deflecting current. A controllable phase shifter for answering to a feed back signal expressing a deflecting current amplitude shifts the phase of the second control signal, with respect to the first control signal. The change of a fly-back capacitive transformation ratio is opposite to that of the deflecting current amplitude. |
