Horizontal And Vertical Deflection Output Circuit And High Voltage Regulator Circuit (Ea Block) - Sony BVM-1916 Operation And Maintenance Manual

3-12. HORIZONTAL AND VERTICAL DEFLECTION
OUTPUT CIRCUIT AND HIGH VOLTAGE
REGULATOR CIRCUIT (EA BLOCK)
3-12-1. Horizontal Deflection Output Circuit
The horizontal deflection output circuit controls H out of Ql 1.
driving T'2 at Ql0 hy the H drive rulse generated on the hoard
DB
The power supply circuit to Hout improves the power supply
efficiency using-150\/ and
DC-DC
converter with IC! and Q7.
I Cl
consiq, of the error amplifier and the P. Vv'. M. circuit IC\.
hcin~ supplied \Vith the side pin-cushion correction waveform
and the H. width adjusting voltage from the board DA controls the
OC-OC
converter output.
3-12-2. H. Center Adjusting Circuit
The H. center adjusting circuit generating a± pov.'cr source
from the secondary output ofD (HO.Tt flows the correction
current of the horizontal center position and Y how hencl to the
horizontal deflection :_.'oke
3-12-3. H. Linearity Correction Circuit
The H. LIN. circuit amplifies the H. LIN. correction waveform
generated on the board DA by the SEPP amplifiers of Q2 to Q5. and
supplies these to the horizontal deflection yoke from the capacitor for S
curve correction
3-12-4. Vertical Deflection Output Circuit
The \et1ical deflection output circuit consists of the SEPP AMP, directly
connected to DC power and composed of 020 I to Q205 and the retrace
pulse voltage boost-up circuit composed of Q207 and Q208.
This SEPP AMP receives, as an input the .,awtooth wave voltage (added
with the T&B pincushion compensating voltage and the vertical linearity
compensating voltage) generated at the DA board.
Since the SEPP AMP is directly connected
to
the load (V.DY). the V
CENT circuit needs only DC current supplied to V sawtooth from
=
power supply. The boost-up circuit is turned on by the V.D signed and
supplies energy to the output ci1Tuit during the vertical retrace period.
3-12-5. High Voltage Regulator Circuit
The high voltage rcgu!a!or of this unit u~es the DC-DC
corn·crtcr type power supply circuit in order lo reduce pow'er
comumption. In general. the mm·ement of the high voltage
regulator is as follows:
The high voltage regulator con~ists of Ql6. Ql.S. JC~ ( 1/2), IC'
(IC for P.W.M. control) and HVR
The ddection \'Oltage is obtained hy directly dividing HV
voltage with resistors in HVR
IC2 compares this detection \'Oltage with the reference voltage
located outside IC2 (error amplification) an<l performs P.W.M.
modulation. Q\6 is driven hy output of IC2 which is made
PWM modulation and control~ the voltage supplied to the FBT
drive circuit (017. QlR. FBn.
The HV voltage is adjusted hy changing the detection voltage.
Since the detection voltage of HVR drops v.'hen the anode
current is increasing: and the high rnltagc drops, then the ON
period of Q]6 is widened
As a result of this, a~ the peak current of the corrector current of
QlB increases. the energy which is stored in C6B via FB.T is
enlarged and the high \'Oltage is regulated hy increasing electric
potential of
C6B.
3-25
When QIS is turned off,
a
flyback pulse 1s generated by the synthesized
resonance action by inductance of L.O.T, F.B.T and the C65. C66. C67
then, the HV voltage is generated by transfered the flyback pulse to the
secondary side. (See Figure)
BLOCK DIAGRAM OF EA BOARD
08, 09
3-12-6. CRT Heater Power Source
The CRT heater power source is supplied from the secondary winding of
LDT
K.O i
-150V
0-------i
oc-oc
CO'-IVERTER
0 C .P
I
1'[--$
'
[
'""
---------------~p~[~E
,
~
TI
-'vQ'~
I
IC I I 06
P, W .M
,c'
l
i------<1----1
~-~
r
"'
"
-
H
ORIV £
'c----,
K ,QRIV[
,
-
0"
H.OUT
f-LC[NT
0---------------------------------
H. LIN (>----
02.03 ,04,05
rl .LIN
'"'
Q201,202,203 ,204,205,206
VERTICAL
i
0 12,013
H. CENT
'"'
J..
.l.
T
~
0'2
RECTIFIER
V.SAWTOOTH\>------j
OUT
f--------------------------------------~
..
,
Q207, 208
+
150V
0------,
RETRACE
BOOST
v.
SYNC
r------iL..!.·~·:' _
_J
°"
+l50V (>----
o.c
p
KV. DRIVE
0-------------,
0"
c,c -oc
CO'-IYERTER
t
-.i&r-
~
"
~
~'o(j'c.
I
P,W.M
IC 2 , 0 I 4
""
0"
Ta
"'
~II~
DRIVE
EA.
(H,OEF
OUT, V. OEF OUT & HV. REG!
TO
HEATER
L.0 .T
POWER
~II[
SUPPLr
C68-
T
"'
o,e
i
"'
CONVERTEP
3-26
800
V
CRT
HEATER
ABL
H.Dr
V,DY
F BT
p
TO
EB
BOARD
""
u
TO
CRT
ANODE