-5-
F7PTV
6. HORIZONTAL OUTPUT
A horizontal oscillation signal is output from pin37 of
IC201 and switches the drive transistor Q431. This
switching signal is current amplified by the drive
transformer T431 and drives the output transistor Q432.
When Q432 becomes ON, an amplifying current flows
directly to DY through C441
➞
DY
➞
0432
➞
GND, and
defection is performed in the last half of the scanning
period. Next, when Q432 becomes OFF, the charge that
had been stored in DY up to that point releases a
resonance current to the resonant capacitors C421/C423
and charges them. The current stored in C421/C423 is
then flowed back to DY, and an opposite charge is then
stored in DY. This opposite charge then switches the
dumper diode in Q432 ON, the resonance state is
completed, and an amplifying current is then flowed
again directly to DY through the dumper diode. By this
means, deflection in the first half of the scanning period
is performed, and when Q432 becomes ON at the end of
the first half of the scanning period, deflection during the
last half is begun, thus completing one cycle.
In the PCC circuit consisting of Q461 and Q462, the
parabola signal supplied from the vertical circuit is added
at the horizontal output stage and pincushion
compensation is performed by varying the DC voltage
bias. Further, the ABL voltage is feedback to the base of
Q462 to compensate for width variations due to
variations in the beam current.
7. CPU <System and Teletext Control>
Pin description
Pin1: Tuning voltage output
Pin2: Brightness control output (6-bit DAC)
Pin3: Contrast control output (6-bit DAC)
Pin4: Colour control output (6-bit DAC)
Pin5: Sharpness control output(6-bit DAC)
Pin6: Not used (GND)
Pin7: Not used (GND)
Pin8: Power ON/OFF output (H:ON)
Pin9: AFT signal input
Pin10: Option SW1 & Keyboard scan input (DC)
Pin11: Option SW2
Pin12: 50/60Hz switch input (50Hz: Hi)
Pin13: GND
Pin14: TV/AV switch output (TV: Hi)
Pin15: S-VHS switch output (S-VHS: Hi)
Pin16: Option SW3 (2AV: Hi)
Pin17: Function signal input for SCART1
Pin18: Function signal input for SCART2
Pin19: Power LED drive output1
Pin20: Option SW4 & Power LED drive output2
Pin21: Ignore output
Pin22: GND
Pin23: CVBS input0 (Internal)
Pin24: CVBS input1 (Internal/External)
Pin25: Black
Pin26: IREF
Pin27: Odd/Even output
Pin28: GND
Pin29: -
Pin30: V-deflection stop output
Pin31: RGB REF
Pin32: Blue output for OSD
Pin33: Green output for OSD
Pin34: Red output for OSD
Pin35: Blanking output for OSD
Pin36: H-sync. input (Horizontal pulse for OSD)
Pin37: V-sync. input (Vertical pulse for OSD)
Pin38~39: Supply (+5V)
Pin40: OSC GND
Pin41: Oscillator input for CPU
Pin42: Oscillator output for CPU
Pin43: Reset input
Pin44: Supply (+5V)
Pin45: Protect signal input (L:Power circuit defects)
Pin46: Ident. signal input
Pin47: R/C signal input
Pin48: Mute output in no picture
Pin49: I
2
C bus SCL (Serial clock)
Pin50: I
2
C bus SDA (Serial date)
Pin51: Option SW5 & Band select output1
Pin52: Band select output2
