PCBS
14 June, 2002
6-46
6.4.3 NCU
6.4.4 PSU
•
+24Vdc, +5Vdc, –12Vdc generation.
•
Fusing lamp AC power supply controlled by the FCU.
Ring
Detection
Circuit
OHDISW
TIP
RING
T1
T2
TRXD
Current
Sensor
Hook1
Hook0
OHDI SW.
NCU
JP1
JP2
ExRing
CML
Relay
Noise
Filter
Surge
Protection
Over-
current
Protection
Surge
Protection
DC Loop
L-
Transformer
CHLSW
DB1
H310D902.WMF
Fusing Lamp
Switching
Circuit
Transistor
Control
Circuit
Photo-
coupler
Voltege
Detector
DC-DC
Converter
Primary
Smoothing
Circuit
FET
24 V
Smoothing
Circuit
Filter
Circuit
Filter
Circuit
+24 V
(Vaa1)
+24 V
(Vaa2)
+5 V
COM
PC2
PC1
T1
PC3
PC4
Relay
RL1
N
L
N
L
AC-IN
Heater Out
HTON
+24 Vs
HTORON
COM
H310D904.WMF