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3. Operational description
As shown in the block diagram, the commercially available AC voltage supplied through the AC cord passes through the N/F section to the rectifying
section where it is smoothed to about 140V then supplied to the invertor section.
The switching system of the invertor section is with one-stone ON/OFF self excitement invertor (RCC system). A stabled DC voltage is supplied to
the secondary side.
3-1. Invertor section
When the voltage across R9 becomes Q1 gate ON voltage through R6, 8, and 9, Q1 turns on to flow a current from 4pin to 2pin of transformer T1
primary winding. Then a voltage is generated in he direction from 6pin to 7pin of the control winding. Q1 gate voltage becomes ON voltage through
L3, C8, and R13. Drain current is linearly increased to charge energy in the primary winding. When however, the drain current of R11 connected to
Q1 source is increased continuously, Q2 is turned on by the potential difference between the both ends of R11 through R10. When Q2 is turned on,
Q1 gate voltage becomes lower than the gate threshold voltage to turn off Q1. At the moment when Q1 is turned off, the energy accumulated in the
primary side is induced to the secondary winding of transformer to generate a voltage which biases diode D10, D16, and D17 in forward bias,
providing a DC voltage through smoothing of each output capacitor.
3-2. Control section (+5V)
By repetition of operations in 3-1, a voltage is generated in the secondary side. +5V is divided by R16, R27, and R18 to input to IC1 R pin. IC1
always monitors the divided voltage. When the output voltage becomes higher than +5V, the divided voltage also tries to be higher. Then IC1
judges it as a rise in the output voltage to light photo coupler PC1 through R23. When the output voltage is decreased, PC1 light quantity is
decreased to lengthen the ON period of Q1,increasing energy accumulated in the primary winding, supplementing the fall in the output voltage. The
above negative feedback control is repeated to stabilize the output voltage.
C5
820µF
200V
GU(NSN)
R5
100K
3W
C6
0.01µF
630V
QXN
D2
D3
AG01 x 2
R6
200K
2W
C7
2200PF
2KV
HR
Q1
2SK2699
R11
0.47
2W(3W)
RGC(HRNM)
R13
100
3W
C8
473K
L3
RS208
CN5
5550-06A
CN6
5550-06A
R8
10K
R9
10K
D4
D1FL40
D5
HZU24B3
(RD24SB
DTZ24C)
D7
HZU11B1
(RD11SB1
DTZ11A)
5
4
6
PC3
TLP747JF
(TLP741G
/741J)
R41
2.7K
R15
2.7K
R14
22
C9
332K
C12
103K
R12
22K
3
4
PC1
TLP721F
(TLP621)
R17
100
C10
103K
100V
C11 104K
R10
2.2K
D6
1SS193
Q2
C2873
D8
1SS193
D21
1SS193
R16 100
4
2
T1
P1165
7
6
1
2
3
4
5
6
6
5
4
3
2
1
11,12
13,14
D10
SF10SC4
Q3
2SK2512
(K2312)
R37
1K
R20
10K
8
1,2
3,4,5
6
7
IC1
SR101
R36
56
C30 C31 C32 C33
2200µF/10V PW(PY)
x 4
TS1
67F110
L4
SBC6-4R7-802
R22
330
C18
C19
104K
100µF/10V
PW(PY)
8
9
10
+5V
+5V
+5V
GND
GND
5
6
R26
1KF
1
2
PC1
R23
390
R
K
A
R24
1K
R25
1K
C17
1µF/50V
PR(ST)
IC2
HA17431
(UA04-TL)
D11
HZU6.2B1
(RD6.2SB1
DTZ6.2A)
R21
100
PC3
1
2
R27
68F
R28
1KF
6 – 2
Содержание UP-5700
Страница 139: ...1 UP 5700 Main PWB CHAPTER 10 PWB LAYOUT A side 10 1 ...
Страница 140: ...2 UP 5700 CPU PWB A side UP 5700 CPU PWB B side 10 2 ...
Страница 141: ...3 UP 5700 KEY I F PWB A side CN2 UP 5700 KEY I F PWB B side 10 3 ...
Страница 142: ...5 UP 5700 INVERTER PWB A side UP 5700 ISA PWB B side UP 5700 INVERTER PWB B side 4 UP 5700 ISA PWB A side 10 4 ...
Страница 144: ...For components produced in January 1998 and onward Parts side Solder side 10 6 ...
Страница 145: ...7 2 Sub PWB Side A Side B 10 7 ...