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6-5. E Board and EA Board
1. Horizontal system
. H. delay circuit
IC2002 generates the positive polarity pulse as it is triggered by the fall-down edge of the H. sync signal
that is supplied from the BC board. This positive polarity pulse is inputted to IC2001 (deflection proces-
sor). However, because the H. sync from the BC board is inverted during the H. delay mode, the positive
polarity pulse is delayed by about 1/4 of the horizontal period i.e., the H. sync pulse width.
. AFC circuit
IC2001 is the deflection processor IC that performs sync and deflection signal processing. IC2001 is
automatically pulled into the input sync signal. IC2001 compares phase and frequency so that the H.
OSC signal of pin-10 is locked to the positive polarity pulse that is supplied from the H. delay circuit to
pin-38. IC2001 also outputs the H. DRIVE pulse from pin-21 so that the horizontal deflection output
pulse (AFC.P) that is wave-shaped by Q25 to Q28 and IC1005 is synchronized with the H. OSC signal.
The H. DRIVE pulse has the function of the horizontal picture phase adjustment (H. PHASE) function,
the horizontal pin cushion correction (H PIN BAL) function and the horizontal key balance correction (H
KEY BAL) function.
The H. PIN voltage that is outputted from pin-31 has the function to correct the horizontal pin distortion
(H PIN) and key distortion (H KEY).
. Horizontal deflection circuit
The H.DRIVE pulse performs switching of Q2 (H OUT) via Q1 and T1 (HDT) to drive the H. DY. In
order to improve power supply efficiency of the horizontal output circuit, the power supply is generated
by switching Q703 with the PWM pulse that is generated by IC701 and IC702. The H. WIDTH voltage
and the H. DY current that is detected in the form of the detection voltage and is converted by T4 and
R42 are inputted to IC701 so that power supply voltage is controlled.
The identification signal that identifies the horizontal frequency, which is outputted from IC7001, is used
to select the S-curve capacitors C10 to C17, the horizontal linearity coils L1 and L2, and the resonance
capacitors C6, C25 and C26.
. Horizontal centering circuit
The positive and negative polarity power supplies of the horizontal centering circuit are generated from
the secondary output of T2 (HOT). In the horizontal centering circuit (IC101, IC102, Q101), the DC
current that flows through the H. DY is controlled by the H. CENT signal that is supplied from IC7005.
. Horizontal linearity circuit
The H. LIN signal that is outputted from IC205 on the D board is amplified by Q201 to Q207, drives T3
(HLT) to flow the horizontal linearity correction current.
6-14
BVM-D32E1WA/D32E1WE/D32E1WU
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