| 摘要 |
In a field effect transistor (FET) discharging circuit for a horizontal deflection circuit, a backward voltage is removed by employing a diode to discharge a high level voltage formed on the FET. The FET discharging circuit includes: a horizontal oscillator responsive to a horizontal synchronous signal from a microcomputer for generating an output having the same horizontal oscillating frequency as the horizontal synchronous signal; a horizontal driving unit responsive to the output of the horizontal oscillator for generating an amplified pulse waveform of the same frequency as the horizontal oscillating frequency, and for outputting the amplified pulse through a transformer which provides electrical isolation from a high level power circuit; a horizontal outputting unit responsive to the output of the horizontal driving unit for supplying a current to a horizontal deflection coil, the horizontal outputting unit being connected in parallel to a damping diode and a resonance condenser for resonating with the horizontal deflection coil; and an S-shaped correcting unit connected in series with the horizontal deflection coil for linearly correcting a distorted displayed image, the S-shaped correcting unit having a discharge device for instantly discharging when a high overvoltage is generated because of abnormal operation. The horizontal deflection coil is connected in series with the horizontal outputting unit for receiving an output current from the horizontal unit, and generates a sawtooth current to adjust right and left deflections of an electron beam on a screen. As a result, any overvoltage formed at the transient state, when the FET is turned on or off, is removed by a quick discharging effect, thereby improving performance of the circuit.
|
