Mitsubishi Electric 1786FD2 Service Manual page 52

MEA 1786FD2 CRT Monitor Service Guide
Circuit Operation Theory
6. BDRV and step-up CKT
6.1 The "BDRV" signal from TDA4856 pin6 is a square waveform. It is inverted and amplified by
Q201. Q310 and Q311 constitute a buffer stage.
6.2 Q312, L301, D318, C323 is step-up circuit B+ = 50V * ( ton + toff ) / toff.
Fig 6 BDRV & Step-up circuit
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