Advertisement
DP-4X VERTICAL OUTPUT CIRCUIT EXPLANATION
(See the Vertical Output Circuit for details)
I601 B+:
The Vertical Output IC I601 requires SW+28V to operated. This voltage is supplied from the Power Supply. The
output for the SW+28V pulse is from pin 16 of TP01. Its then rectified by DP30, filtered by CP32, LP30, CP34.
The SW +28V is routed through the Vertical B+ Excessive Current Sensor R629, Q604 to pin 7 of I601.
TRIGGER PULSE:
The Vertical Drive Trigger pulse is routed from the Rainforest IC IY04 pin 35 on the Signal PWB. It is output to
the PDS2 connector pin 10, to the Sub Deflection PWB PDD1 connector pin 4. Then into pin 21 of IB01. This
IC generates the Vertical Drive signal out pin 4 to the PDD1 connector pin 2. Then to the Deflection PWB. It is
then sent to the Trigger Input on I601 pin 6.
During Trace, the internal Ramp Generator circuit using C602 connected to pin 5 as the time constant begins
charging. As it charges, the Pump Up circuit is also charging from the SW+28V to C605, through pin 8 to an in-
ternal switch inside I601. When the Trigger pulse arrives (Retrace Time), the internal switch toggles over to the
output stage push pull pair inside I601, and the +28V charged capacitor C605 discharges. The output stage push
pull pair inside I601 already have +28V input from pin 4. So the output pulse from pin 3 is now near 50V p/p.
This is only needed for a short duration of time, (retrace) so the Charge Pump circuit eliminates the need for a
50V power supply.
(V BLK) VERTICAL BLANKING PULSE GENERATION:
When the Charge Pump discharges and produces the 50V p/p pulse for Vertical drive during retrace, this pulse at
pin 8 is also routed as the Vertical Blanking pulse. It's amplitude is around 21V p/p and is sent to the following
circuits;
•
Vertical Sweep Loss detection circuit
•
Convergence circuit for vertical correction waveform generation
VERTICAL OUTPUT PULSE FROM I601:
The Vertical Output pulse from pin 3 is then routed to the Vertical Yokes generating a linear sawtooth current
which moves the beam. (Trace = from top to bottom, Retrace = from bottom to top). This linear current is gener-
ated by the charge time constant of the vertical yokes charging C607 through the low ohm resistors R619, R620.
VERTICAL YOKE CHARGE PULSE:
The pulse generated on the positive side of C607 is also routed through the parabolic wave form generation cir-
cuit of R616 and C606. Then to the PDD1 connector pin 3. Then to pin 6 of IB01. This IC then generates a Ver-
tical Parabolic signal from pin 18 through QB04 that is sent to the dynamic focus circuit for corrections to focus
and from pin 10 to IB02 pin 3 for side pincushion correction.
The pulse generated on the positive side of C607 is also routed back to I601 pin 4. The AC component of this
signal is for vertical linearity compensation. The DC component of this signal is routed back to the Ramp genera-
tor circuit described above.
The Vertical height is now adjusted by I
D SIZE SWITCH:
When Magic Focus is activated by either the Magic Focus button or customer's menu or during service when the
sensors are initialized, The Microprocessor I004 receives the D Size signal from the Digital Convergence Unit,
UKDG pin 35 then to the PDS2 connector pin 7. When the Micro. Receives this signal at pin 43, it knows to in-
creases the Vertical size to allow positive contact of the light pattern hitting the sensors. It does this by I
communications to IB01.
2
C data communications to IB01.
2
C data
PAGE 05-07
Advertisement
