High-voltage power supply device

Abstract

The invention relates to a high-voltage power supply device. The high-voltage power supply device comprises a driving unit, a piezoelectric transformer and a smoothing unit. The output of the drivingunit drives the piezoelectric transformer. The smoothing unit comprises a high-voltage diode, a resistor and a first capacitor. The positive pole of the high-voltage diode is connected with the outputend of the piezoelectric transformer, and the negative pole of the high-voltage diode is connected with the first resistor and the first capacitor. The first capacitor is grounded, and the other endof the first resistor serves as the output end. According to the high-voltage power supply device, signals which drive the frequency oscillation are generated by the driving unit, the piezoelectric transformer outputs the maximum voltage at the resonant frequency under the action of the driving signals, the first resistor suppresses the voltage, which is generated by the piezoelectric transformer, of the spurious frequency to generate the voltage at the frequency lower than the resonant frequency, and therefore the degree of distortion of the output voltage is reduced, the output voltage is slightly affected by the external load of the first resistor, temperature changes and other factors, the stable output voltage control is achieved, and the image transfer printing quality is improved.

Description

technical field [0001] The invention relates to a high-voltage power supply device, belonging to the field of power supplies. Background technique [0002] In the image transfer process of laser printers or copiers, image transfer is achieved by applying voltage to the transfer roller. In order to achieve a good transfer effect, a high voltage (several hundred volts higher than the voltage of a commercial power supply) and a current of about 10 μA need to be applied to the transfer roller. [0003] To generate such high voltages, wire-wound electromagnetic transformers have traditionally been used. However, the electromagnetic transformer is bulky and heavy, which is an obstacle to reducing the size and weight of the high-voltage power supply device. Therefore, research began on the use of piezoelectric transformers (piezoelectric ceramic transformers). With the piezoelectric transformer, a high voltage can be generated with higher efficiency than the electromagnetic tran...

AI Technical Summary

Problems solved by technology

[0004] In the circuit design of a general piezoelectric transformer type high-voltage power supply unit, the output voltage is controlled according to the frequency, however, in the conventional circuit design, spurious frequencies are generated in the resonant frequency range

When spurious frequencies are generated, the output voltage becomes unstable in response to changes in the load, making it difficult to obtain high-quality images

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