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 cord is plugged into a power receptacle and the power switch is in the off position. You must unplug the product power cord before servicing the product.
Figure 1-10 Low-voltage power supply (LVPS) 16 Chapter 1 Theory of operation ENWW AC input Engine controller Low-voltage power supply DC controller Fuser unit Fuse (FU101) Fuse (FU201) Cartridge-door switch High-voltage (SW501) power supply +24U Rectifying circuit Frequency FREQSNS detection circuit (220-240V model only) BSTSIG +24V generation +24V circuit 24VON +24V ON/OFF +24P circuit +5V +5V Protection generation +5R circuit circuit +3.3V +3.3V generation circuit +3.3VON +3.3V ON/OFF +3.3UON circuit +3.3U +3.3R Formatter Power switch (SW502) +3.3R Formatter Low-voltage power supply Re c ctify ircu ing it +24V 24VON +24P +5V +5R +3.3V +3.3VON +3.3UON