Circuit Operation Theory - Mitsubishi Electric 1786FD2 Service Manual

MEA 1786FD2 CRT Monitor Service Guide
3.2 Rectifier and filter
L
AC INPUT
N
When power switch is turn on, the AC voltage is Rectifier and filter by D602~D605, C612. The DC
output voltage will be 1.4*(ac input)
3.3 switching Element and isolation transformer
C608
47U
25V
(EL)
In a flyback converter operated in the discontinuous mode, the energy stored in the flyback
transformer (actually an inductor) must be zero at the beginning and end of each switching
period .
During the "ON" time, energy taken from the input is stored in the transformer when
the switching transistor turn-off, this stored energy is all delivered to the output.
D602~D605
3
~
4
-
~
2
B61
R604
C613
82K 0.01U
1KV
2W
(D)
C50
D610
C614
UF4007
(OPEN)
C51
D608
RGP10D
Q602
FS14SM-12
L607
(BEAD)
D614
R608
UF4007
20K
R607
0.15
2W
R611
1K
20D6 * 4
1
+
C612
+
220U
DC OUTPUT
400V
(EL)
6
ZD601
(OPEN)
D613
(OPEN)
L606
1
(BEAD)
L608
(BEAD)
8
C624
220P
1KV
(D)
R619
470
2W
*
9

Circuit Operation Theory

FR701
T601
11
(SHORT)
12
FR702
10
(SHORT)
15
18
16
FR704
(SHORT)
13
EGP30B
C53
1 3