ULTRASONIC FREQUENCY AC BIAS FOR AC CORONA GENERATING APPLICATIONS
Original Publication Date: 1995-Aug-31
Included in the Prior Art Database: 2004-Apr-07
Xerox Disclosure Journal
A typical corona generating device is provided with a high voltage AC bias operating in the frequency range of 400 to 600 Hz. At this frequency, a power supply must incorporate transformers that are physically large and heavy. Such low frequency transformers are typically very expensive and also represent a significant barrier to modulaFization, and miniaturization of xerographic power supplies. In addition, such large transformers are characterized by high load capacitances and stray capacitances which result in excessive power losses. Since these capacitive power losses do not contribute to the corona generating current, the losses represent a large portion of the power delivered by the power supply. The present disclosure is directed toward reducing capacitive power losses in a corona generating power supply by utilizing ultrasonic frequency AC bias for an AC corona generating device. The use of such ultrasonic frequency devices permit a substantial reduction in physical size and weight of the power supply so that the cost of the high voltage AC power supply may be substantially reduced.