Table of Contents
Advertisement
Power
ACin
relay
(S701)
Main
sectoin
24V
ON/OFF
CLPR
control
24V(SW)
PMW
CLCON
signal circuit
(2) Circuit description
1
Main circuit
a. Noise filter circuit
The noise filter circuit of the DC power is composed of L as shown in
the figure below. It reduces the normal mode noises which come from
the AC line.
The normal mode noises are noises which are overlapped in the AC
line or the output line, and are attenuated by L701.
L701
SC-07-300J
(L)
CN 701-1
(N)
CN701-2
Fig. 2 Noise filter circuit
b. Rush current limit circuit
Since the AC power is directly rectified, without this circuit, en ex-
tremely great rush current would be generated by the charging cur-
rent flowing to the smoothing capacitors (C707, C708) and the switch
contact would be deteriorated.
To prevent against this, the circuit composed as follows is inserted
between the rectifier diode (D701) and the smoothing capacitors
(C707, C708) to limit the rush current. When the power is supplied, a
charging current flows through R702 and FA701 to the smoothing
capacitor so that the current at supplying the power is limited to 30A
or less. (Fig. 3, Fig. 4)
After that, the smoothing capacitor voltage rises to operate the inver-
tor circuit. Then the voltage generated in the convertor transformer
triggers the triac (TR701) to ON. Therefore, in the normal operation, a
current flows through TR701 and does not flow through T702 and
FA701.
Rush current
Rectifying/
Noise filter
limit circuit
smoothing
Regulator
circuit
Fig. 1 Block diagram
Chopper
circuit
Drive
Current
transformer
transformer
(T702)
(T703)
Control
circuit
TR701
BCR16PMBLAA
FA701
R702
4.7
4.7/135K
7W
D701
S15WB40
Fig. 3 Rush current limit circuit
SAMPLE
T1
5.0mS
T2
0mS
T3
0mS
T4
0mS
T5
0S
TA
0mS
TB
500mS
RATIO
0%
PRINT
0mS
TA
TB
500mS
A-RMS
3.520A
A-PEAK
22.36A
ƒI²t
6.199A²S
V-RMS
115.1V
W
200.0W
SPEED
120mm/S
9 – 23
Rectifying/
smoothing
Transformer
(T704)
Overcurrent
protection
(PC707)
circuit
CL monitor
circuit
(PC708)
D702
R704
R705
47(1W)
47(1W)
ERA9102
R703
1K
L702
BO1A
C709
L703
0.1/400V(QXJ)
BO1A
C710
R709
27K(2W)
470P/1KV(HR)
R710
27K(2W)
50A
E4
40A
E3
30A
20A
10A
0A
10A
20A
30A
E2
40A
E1
50A
Fig. 4 Rush current
CL output
CLMON
T701
N-T01-007
500
500
Advertisement
Table of Contents
