Daewoo DQD-2100D, Service Manual

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14
CIRCUIT OPERATIONAL DESCRIPTION
Picture
3 [
Sunbber circuit
]
3) Sunbber circuit
Sunbber circuit protects speedy voltage rising between Collector and Emitter when Main Switching TR is
turned off. So Collector and Emitter voltage enter into safety operation and noise is decreased. When TR
is turnd off, because high reverse voltage is generated between Collector and Emitter, it is rectified to
D802, smoothed to C807 and consumed to R809. C808 is Speed-Up Capacitor.
4) Switching and Control Drive Circuit
When Base of TR is charged through starting part, TR is turned on. So voltage is added to primary
winding of transformer and genertaed at Base Drive. Because this voltage becomes to Positive Feedback
voltage, TR is turned on again and Primary Winding of Trans is charged with electricity .
Picture 4 [Drive Circuit]