Hitachi CMT2988 pillow calibration circuit

Relevant key device information applied in this article: AN5551 C458 C2373 and Hitachi CMT2988 pillow calibration circuit are the same models: Hitachi 25M8C, CMT2518, CMT2718, CMT2916, CMT2588, CMT2598, CMT2998, Furi HFC2581, 2586, 2587, 2986 ,2987 etc. The sawtooth wave voltage of about 4V (peak-to-peak value) at both ends of R617 is added to pin (1) of IC651 through C651 and R651. After its internal amplification and integration processing, a voltage of about 2V (peak-to-peak value) is output from pin (2). The concave parabolic wave voltage is integrated by C653, C652, and R666. The amplitude of the parabolic wave is adjusted by R657, and then added to pin (7) of IC651 via C655. After internal amplification and shaping, it is output from pin (8). After the convex parabolic voltage is followed by the Q652 emitter and reversely amplified by Q651, a concave parabolic voltage of about 9V (peak-to-peak value) is formed at both ends of C727, which is sent to the horizontal deflection coil through L703, and the horizontal deflection current is Modulation, corrected for pincushion distortion. R655 is the line width adjustment potentiometer, and R657 is the pillow adjustment potentiometer.