– 70 –
4. Power Circuit for P.W.B.
●
Fig. 4-1 shows the power circuit for P.W.B. and waveform at each point.
3A fuse
AC 220V
R805
C810
C3
C
C811
R4
L1
Q1
Q2
C4
C2
C5
VR2
D2
D4
D1
R2
R5
R6
R1
C1
D61
D62
D63
D64
D65
RC61
C61
C62
C63
C64
C65
C66
M52
—5V
5V
0V
12V
(12 - H)
(12 - E)
(12 - E)
(12 - D)
(12 - D)
(12 - C)
(12 - C)
(12 - C)
a
c
b
d
e
f
g
h
C711
C712
R62
R63
R64
I / F 35V
I / F GND
C67
C51
C6
RC62
R51
P151
M51
3
2
4
1
R52
R53
R54
R 3
R8
R 9
ZD3
●
In the power circuit for P.W.B., power voltage for microcomputer, peripheral circuits, and power module
drive and, as well as DV35V, are produced by switching power circuit.
●
Switching power circuit performs voltage conversion effectively by switching transistor Q1 to convert
DC270V voltage to high frequency of about 20kHz to 70kHz.
●
Transistor Q1 operates as follows:
(1) Shifting from OFF to ON
●
DC about 270V is applied from smoothing capacitors C810
!
and C811
@
in the control power circuit.
With this power, current flows to base of transistor Q1 via R1 and Q1 starts to rurn ON. Since voltage in
the direction of arrow generates at point
C
at the same time, current passing through R5, R6 and D2 is
positive-fed back to Q1
Fig. 4-1 Power circuit for P.W.B.
Содержание RAC-25CNH11
Страница 35: ... 35 CIRCUIT DIAGRAM MODEL RAS 25CNH11 ...
Страница 36: ... 37 CIRCUIT DIAGRAM MODEL RAC 25CNH11 ...
Страница 104: ... 113 PARTS LIST AND DIAGRAM MODEL RAS 25CNH11 11 2 18 8 20 19 12 63 1 4 60 3 7 14 15 6 5 16 13 88 61 17 9 62 10 ...
Страница 106: ... 115 MODEL RAC 25CNH11 55 22 59 16 26 24 23 20 21 19 13 52 58 53 56 57 2 3 51 15 14 18 4 5 9 6 8 54 17 7 11 10 12 25 ...
Страница 108: ...RAS 25CNH11 RAC 25CNH11 PM NO 0164E Printed in Malaysia HITACHI ...