BenQ v772 free download

File name V772 circuit operation theory.pdf

V772 CRT Monitor Service Guide Circuit Operation Theory ACER V772 DEFLECTION CIRCUIT OPERATION THEORY 1. The Block Diagram of Deflection: H-sync Digital Tilt Rotation V-sync Controller Circuit C il I2C BUS AutoSync Deflection Controller IC TDA4856 Vertical Deflection Output Step Up IC TDA4866 for B+ G1 & Spot Dynamic Killer Circuit Focus H-SIZE Compensation Shut down Circuit G1 Dynamic Regulation Feedback Horizontal Deflection Output Circuit 1 Confidential V772 CRT Monitor Service Guide Circuit Operation Theory 2. Autosync Deflection Controller (TDA4856) 2.1 pin 1 is AFC feedback. 2.2 pin XRAY: if V XRAY > threshold (6.25V typical) switches the whole IC into protection mode. 2.3 pin 3,4,5,6,8 for B+ control function block. 2.4 pin 11(EWDRV) is a parabolic waveform used for pincushion correction 2.5 pin 16 generates video claming & blanking pulse. 2.6 pin 18,19 is I2C data. 2.7 pin 21 V-regulation. 2.8 the resistor from pin 28 (HREF) to ground determines the maximum oscillator frequency. 2.9 the resistor from pin 27 (HBUF) to pin 28 defines the frequency range. 2.10 pin 31 H-regulation. 2.11 pin 32 focus. +48V ZD204 +14V