TA8859 pillow calibration circuit

The field excitation pulse signal is directly added to pin (13) of N402 (TA8859) to trigger the internal monostable trigger to generate a field frequency pulse with constant pulse width. After shaping, it controls the field sawtooth wave forming circuit, so that N402 (15) The pin is connected to an external sawtooth wave to form a constant current charge of the capacitor C418, forming a sawtooth wave current. The amplitude and charging speed of the sawtooth wave are controlled by the N402's AGC circuit to meet the needs of 50Hz/60Hz. The sawtooth wave generated by the sawtooth wave forming circuit undergoes a series of linear corrections inside the N402, and then a field excitation pulse is output from pin (8).
The parabolic voltage output by pin (2) of N402 (TA8859), after being amplified by V401~V403, outputs a parabolic wave from the collector of V403 and sends it to the horizontal deflection coil, thereby changing the current flowing through the horizontal deflection coil, that is Correction of east/west pincushion distortion completed. The correction amount of east/west pincushion distortion needs to enter the bus adjustment state and adjust the bus.

Pin 1: 3.7V - high voltage stability detection input terminal

Pin 2: 1.1V——parabolic wave output terminal of East-West Pillow Calibration

Pin 3: 12.0V——+12V voltage input terminal

Pin 4: 5.5V - East-West pillow calibration feedback input terminal

Pin 5: 0V - ground

Pin 6: 4.2V——Field scan feedback input terminal

Pin 7: 0V - empty pin

Pin 8: 2.1V——field sawtooth wave voltage output terminal

Pin 9: 4.8V - bus data line connection end

Pin 10: 4.8V - bus clock line connection end

Pin 11: 0V——empty pin

Pin 12: 0V - ground

Pin 13: 4.4V——Field excitation pulse signal input terminal

Pin 14: 3.8V - pulse shaping external filter end

Pin 15: 6.0V - field scanning sawtooth wave voltage forming terminal

Pin 16: 3.0V——Automatic gain control filter end