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from the vertical deflection output stage through
integrator formed
by
R720 and C717.
The output voltage
of IC702 is adjusted
by
the Side PCC potentiometer
VR704.
This output voltage produces the parabolic
modulation of the horizontal power supply through C715.
The Correction voltage modulates the horizontal yoke
current to correct the Side pincushion distortion.
The Top/Bottom PCC is composed of the balanced modu-
later IC701.
A horizontal parabolic voltage is applied
to IC701 derived from C517 and C518 through C702 and
C703.
Vertical yoke current flows through the feedback
resistors R408 and R409, and is applied to IC701.
The modulated output signal is applied to the vertical
drive stage of IC503, pin number 3 through the Top/
Bottom PCC AMP potentiometer VR702.
This correction
voltage modulates the vertical yoke current to correct
top and bottom pincushion distortion.
Pincushion phase
is adjusted by potentiometer VR703.
3.5.4
Horizontal Voltage Control Circuit
The horizontal voltage control
circui~
operates to keep
the horizontal width constant for a line rate range of
28
KHz
t~
34 KHz line rate.
The control circuit is composed of the error amplifier
Q503 and horizontal voltage regulator Q504 and Q552.
To detect output voltage the rectifier horizontal
retrace pulse is utilized to keep constant width.
The
rectified voltage source is developed across capacitor
C525.
The error amplifier Q503 compares the attenuated
rectified voltage source applied to base through VRSOS,
with Zener voltage of 0507.
The amplified voltage
difference developed across R531 drives the base of
Q504 to maintain a regulated output voltage level.
Potentiometer VR505 is used to provide horizontal width.
3-14
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