Electric power source
US5532913A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 1994 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Mar 21, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/48
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An AC high-voltage power supply circuit, adapted for use in an image forming apparatus, for example in the separation charger of an electrophotographic copier, and capable of controlling the DC component of an AC high voltage, over a wide range including positive and negative regions. The power supply circuit includes, at the low voltage side of a secondary coil of an AC high-voltage transformer, a DC constant current circuit consisting of a transistor and a diode, a constant voltage circuit opposite in polarity to the DC constant circuit, and a detection circuit for detecting the DC component of a load current. The outputs of the constant voltage circuit and of the DC constant current circuit are controlled according to the output of the detection circuit. Such a device has a simple structure, provides a wider control range of the DC component including positive and negative regions, and has a lower power loss than previous power supply circuits.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.