Page: 21Service Guide OL400Chapter 2 Principles of Operation2.3.04 Power Supply UnitThe power supply unit generates the following voltages from the AC input voltage.Voltage Purpose+5vdc Logic Levels, LED Head Drive Voltage+12vdc Interface Line Voltage-12vdc Interface Line Voltage+38vdc Motor/Fan Drive Voltage: High Voltage Source+5Kvdc Transfer Charge Voltage-6Kvdc Drum Charge Voltage-600vdc Charge Grid Voltage-550, -400vdc Developer Bias VoltagesHigh Voltage DriveThe high voltage circuit provides a charge voltage (about -6Kvdc), a transfer voltage (about +5Kvdc), a grid voltage (about -600 vdc), and a developer bias voltages (about -550vdc and-400vdc). Of these voltages, the first two are generated from a high voltage power supply. Thegrid connects to the ground via a varistor on the medium-voltage generation circuit (LLAB-PCB). Itis kept at about -680 vdc during charging.Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA BusinessPartner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)
