Horizontal Deflection Circuit - Tatung OMNISCAN SERIES Service Manual

TEST
TEST TEST POINT NAME
CONDITION POINT
Fh=31KHz F1
OSC VOLTAGE
F2
BUFFER OUTPUT
F3 DRIVE VOLTAGE
F4 DRIVE VOLTAGE
F5 OUTPUT PULSE
F6 CS VOLTAGE
fl~rrj~~~fH
I-r
-r
jT. -
!
11--11
lltl-I=~jJ-ltj
F4 12 Vpp
F5 840 Vpp
I
I
I, "
i : ,
' 1
! ! I
I!
" ! , ,
r-i -i-,-r
!
l
LLLJ
i
R i :
fiHRlr
I-I
i
TI\
i I
I
ir
H-n
IlTr\
1--1
I
I
.LJ~~LJ~-_I
--I
U . . .
J __
Lt_ . . LL_1 L.l. _ _ _
F6 25 Vpp
Il
I I
I
I I
I I
i
I I
I
I I I
!
!
il
f\
I (!\
I
fl
\!
,
I
I \! V !
\1 /
i
71
I
i
~ I
I I
' . I
I
i
I
\
\
'J I
V
IV
JJ.
,
I
,
I
i
3.18 HORIZONTAL DEFLECTION CIRCUIT
(Refer to circuit diagram Fig-18)
A horizontal deflection output circuit uses the
transistor's switching function, combined with a
damping diode and makes sawtooth wave current
flow through a deflection coil.
The basic deflection circuit comprises switching
transistor 0411 ,transformer T401, diode 0405, 0415,
0416, C423, C424, and the horizontal deflection coil
connected to P404. Network L402-L405, R473-C426,
R466-C427, modifies the current wave form in the
deflection coil to give good horizontal picture linearity.
In 31KHz operating mode
0414 is on, relay RY401 is open, L402 and L405 are in
series.
0420 and 0421 are on and S correction is provided
by the combination of C428, C429 and C430,
In 48KHz operating mode
0414 is off, relay RY401 is short, L405-R466-C427 is
short, linear coil is provided by L402 along,
0420 is on, 0421 is off, S correction is provided by
the combination of C428 and C430.
=
3-15
=