25
Deflection Block
Horizontal
IC1301 YCJ generates the horizontal drive signal and outputs it from pin
34. This signal is first applied to horizontal drive transistor Q501 and is
then applied to the horizontal drive transformer T501 and coupled to Q502,
the Horizontal Output. The signal from the Horizontal Output is sent to
the horizontal yoke and the FBT T505. The horizontal deflection yoke
controls the beam scan horizontally. The Horizontal Output circuit also
outputs a sample of the H output that is squared off. This signal is called
HP. HP is returned to the Pin circuit, YCJ for H phase compensation, and
the D board on applicable models to create certain signals used by Dy-
namic Focus and Quadra-pole.
T505 FBT boosts the horizontal drive signal to create the high voltage,
G2, heater and focus voltages required by the picture tube. The FBT
creates an ABL signal which is representative of the current drawn by the
tube. This signal is used to limit the picture brightness and to compen-
sate for high voltage regulation. In addition, scan derived power supplies
are generated by the FBT. They are the +200, +12 and – 15 volts.
Pincushion
A 60 Hz parabola signal is output from the IC1301/11 E/W and applied to
the Pin Out circuit. This signal is compared with the HP signal to create a
Pulse Amplitude Modulated signal that is applied to the Horizontal circuit.
The purpose of this signal is to create a uniform picture width on the
screen
Vertical
The vertical drive signals are generated by the YCJ
after it successfully
completes initial communication with the Syscon
. These signals are
output from IC1301/13 and 14 and are applied to IC502 Vertical Out. The
output from IC502 Vertical Out is applied to the vertical yoke to control the
scanning of the beam vertically. The vertical output also generates a
boost pulse that is returned to the Syscon IC for self-diagnostics. This
boost pulse is also sent to the D board to create certain signals.
Dynamic Focus and Quadra-pole
The D board is used in all 27” and above models. This is because dy-
namic focus and Quadra-pole are necessary for larger FD Trinitron tubes.
The dynamic focus control uses the VP and HP signals to develop a sig-
nal, which will be used to sharpen the left and right sides of the picture.
The Quadra-pole circuit uses the VP and HP signals along with the posi-
tive vertical drive signal (VD+) to create a signal that will be applied to a
series of coils. The magnetic field of these coils is used to sharpen focus
in the four corners of the picture.
Summary of Contents for FD TRINITRON WEGA KV-13FM12
Page 27: ...22 NOTES ...
Page 48: ...APPENDIX ...
