Page: 26Service Guide OL830Chapter 2 Principles of Operation2.3.03 Power Supply UnitThe power supply unit generates the following voltages from the AC input voltage:High Voltage DriveThe high voltage circuit provides the charge voltage (about -6 Kvdc), transfer voltage (about +5Kvdc), grid voltage (about -600vdc), and developer bias voltages (about -550vdc and -400vdc). Ofthese voltages, the charge voltage and the transfer voltage are generated by a high-voltage powersupply. The grid connects to ground via a varistor on the medium-voltage generation circuit. Thiskeeps the grid at about -680vdc during charging.Low Voltage CircuitThis circuitry produces the following voltages:+5 vdc: Printer Logic+/- 12 vdc: Interface Signal Levels+38 vdc: Resist/Main Motor Drive, Fan DriveCopyright 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)
