User Guide

Low-voltage power supply
The low-voltage power supply (LVPS) converts ac input voltage to dc voltage. The LVPS has two fuses on
the PCA. The LVPS 24 V output is interrupted to the fuser and the high-voltage power supply if the
cartridge-door interlock switch (SW501) is in the off position (cover open).
WARNING! The product power switch only interrupts dc voltage from the LVPS. The ac voltage is
present in the product when the power cable is plugged into a power receptacle and the power switch
is in the off position. You must disconnect the product power cable before servicing the product.
Figure 1-13 Low-voltage power supply (LVPS)
+3.3VB
+5V
+24VC
Fuse (FU1002)
Fuse (FU1001)
+24VD
Fuser
control circuit
+3.3V
+24VB
Fuser
DC controller
Low-voltage power supply
+5V
generation circuit
+3.3V
generation circuit
Protection
circuit
+24V
generation circuit
Rectifying
circuit
Interlock switch
(SW260)
Power switch
SW240
Power switch
control circuit
High-volage
power supply
Main motor
Formatter
22 Chapter 1 Theory of operation ENWW