CIRCUIT OVERVIEW (continued)
SWITCH MODE REGULATORThe voltage output of the rectifier (150VDC) is supplied
This chassis has a switching power supply (quasi-to the Main Switch Mode Regulator Power Supply (SMPS)
resonant topology type). The AC line is routed through& Standby Switch Mode Regulation Power Supply. Its
the fuse FX3400 (4A @ 250 V fast blow) and thenoutput should be operating in the range of 127.3 VDC
through the bridge rectifier circuit BR3400 and CX3407.to 190.9 VDC.
The AC operation range is between 90 Vrms to 135 Vrms.The Main SMPS consists of ICX3400, ICX3401, and
A filter consisting of LX3400 and CX3401 is employedICX3402. Its chopper transformer consists of TX3400
before the rectifier circuit to reduce noise from the ACand the standby SMPS. The standby SMPS consists of
line and vice versa (EMI).ICX3406, ICX3407, ICX3408, and the standby chopper
transformer TX3401.
STAND-BY START UP
Switch Mode Regulator
When the PIN 4 of ICX3406 terminal voltage reaches 16
VDC (typical), the control circuit enables regulator
ACoperation. Once the regulator output voltage is
Line
Stand Byestablished, the drive winding DX3415 starts to charge
Power SupplyCX3430 via DX3415. The voltage on CX3430 thus recovers
to the nominal drive voltage.
Switched
Power Supply
Power
Control
SR23 - 923-035093-7CS - SERVICING |
ACEC
