Operation Theory
Page 13
MD 1998LE (B1997PNST)
Horizontal dynamic focus
3-6 Video Amplifier Section
1. RGB signal inputs are terminated by R501, R531 and R561 then pass through the coupling capacitors
C502, C532 and C562 to I501 M52743BSP preamplifier.
2. The amplifier RGB signals (0~3 Vpp) are adjusted by I
2
C bus, pin 19 is for clamp pulse which comes from
pin 16 of TDA4856 to set up equal clamp level.
3. The video output stages is I901 LM2402, the output resistors R904, R934 and R964 are 47 ohm, R913,
R943 and R973 are 56 ohm for arcing protection and the power dissipation is minimized.
4. The RGB cathodes cut off are adjusted by D/A output pins 24, 25, 26 of I501.