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Switching of the S-shape compensation capacitors is done by Q2512, Q2513, Q2514, Q2515, Q2509 and
Q2510. Switching of the S-shape compensation capacitors is done at the three points of the horizontal
frequency 15 kHz, 27 to 33.75 kHz and 37 to 45 kHz. Switching of the horizontal linearity coils is done
by RY2501 when the 15 kHz signal is input. The H centering circuit consists of IC2503, Q2503 and
IC2502. The H centering adjustment is performed by amplifying the H CENT DC signal output from
IC1506 (D/A) and super-imposing its DC component on the horizontal deflection current using IC2501
and L2503 (HCC). Power to IC2503 is obtained from the secondary winding of T2501 (HOT) via a
floating power supply.
4. Vertical output circuit
The vertical output circuit consists of IC2501 and the peripheral circuit.
The vertical output is generated from the V drive signal that is output from IC1505 pin-8 and amplified
by IC2501 pin-1. The V center position adjustment is accomplished by using the V DC signal that is
output from IC1506 pin-6 and is input to IC1505 pin-7. The V amplitude adjustment and V center
position adjustment are controlled by IC1505.
5. High-tension output circuit
The HV drive signal that is output from IC1509, is input to the high-tension output circuit consisting of
Q506, Q507, Q508 and the peripheral circuit that generates the fly-back pulse. The fly-back pulse is not
only supplied to T502 (FBT) but is also supplied to the C board as the G2 voltage after it is rectified and
smoothed out by D515 and C513.
The high-tension detector voltage is voltage-divided by the high-tension resistors inside the FBT, and is
output from T502 pin-14. This detection voltage is voltage-divided by IC504, R1579, R1581 and R1580,
and is sent to IC1509 pin-17 as the high-tension feedback voltage.
6. Focus signal output circuit
The H focus signal that is output from IC1505 pin-13, is amplified by the H focus amplifier consisting of
Q501, Q502, Q503 and the peripheral circuit, and drives T501 (DFT). The H focus signal feeds the T502
pin-17 after amplification to approximately 500 V with T501.
Because the H focus signal interferes with the white balance reference signal inside CRT and gives
adverse effect, the H focus signal of a constant voltage is supplied during the V blanking period instead of
the H parabolic signal. Switching between a constant voltage and the H parabolic signal is done by Q1504
and C1507.
The V focus signal that is output from IC1505 pin-12, is amplified to approx. 200 V by the V focus
amplifier consisting of Q1509, Q1510 and the peripheral circuit, and is supplied to T502 pin-18.
7. Protector circuit
The HV protector circuit consists of IC502, IC505 and the peripheral circuit. If the voltage at T502 pin-6
(FBT third winding) exceeds the reference voltage that is set by IC514, the HV protector circuit is
activated to operate the power supply protector (+B shutdown) via D514. The operating point of the HV
protector circuit is set to approx. 27 KV (14-inches) or 30 KV (20-inches) of the high-tension output
voltage.
The Ik protector circuit consists of IC502, IC503 and the peripheral circuit. The ABL current is detected
by R526, R507 and R528. The HV protector circuit is activated if the ABL detected voltage exceeds the
reference voltage that is set by IC503. The HV protector circuit activates the power protector (+B
shutdown) via D516. The operating point of the HV protector circuit is set for approx. 1500 uA of the
ABL current.
5-6
PVM-14L5/20L5/D14L5A/D20L5A

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