Panasonic PT-53TWD63, Technical Manual

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Horizontal Output Circuit
Unlike HD television receivers of the past, Panasonic is no longer using different
horizontal drive signals to display the ATSC formats. On the DG Board, the
horizontal frequency of the NTSC, 480i, and 480p signals are all converted to
540p prior to their introduction to the D-Board. The horizontal frequency of the
540p signal is the same as the horizontal frequency of the 1080i signal.
Therefore the complexity of the horizontal output circuit is greatly diminished as
only one frequency is processed at all times.
The 33.75KHz horizontal drive pulse from the DG-Board passes through the
A-Board without alteration and enters the base of Q513 via pin 3 of the connector
A2/D2. Transistors Q513 and Q512 amplify the Horizontal drive signal to the
level required to drive transistor Q501. The horizontal drive signal is then applied
to the horizontal driver transformer T501, which in turn drives the transistor
Q551. The horizontal output transistor, Q551, drives the horizontal output
transformer T551 and the horizontal deflection yoke (not shown here).
Figure 36
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