Claims
- 1. A high voltage power supply apparatus that outputs a constant current or a constant voltage, comprising:a high voltage output circuit for supplying a charger load with a high voltage AC; a detection circuit for detecting an average of the output current of said high voltage output circuit; and a comparator circuit for comparing the output of said detection circuit with a reference value and outputting a signal for lowering or terminating the output of said high voltage output circuit when the output of said detection circuit exceeds the reference value.
- 2. A high voltage power supply apparatus according to claim 1, wherein said detection circuit includes a circuit for smoothing the output of said high voltage output circuit.
- 3. A high voltage power supply apparatus according to claim 1, wherein the charger load charges an electrophotographic image forming apparatus.
- 4. A high voltage power supply apparatus according to claim 1, wherein said high voltage output circuit provides a constant voltage output.
- 5. A high voltage power supply apparatus according to claim 1, wherein said high voltage output circuit provides a constant current output.
- 6. A high voltage power supply apparatus that outputs a constant current or a constant voltage, comprising:a high voltage output circuit for supplying a charger load with a high voltage AC; a current detection circuit for outputting a signal of a voltage proportional to the output current of said high voltage output circuit; a smoothing circuit for smoothing the output of said current detection circuit; a comparator circuit for comparing the output of said current detection circuit with a reference value and outputting a signal for lowering or terminating the output of said high voltage output circuit when the output of said current detection circuit exceeds the reference value.
- 7. A high voltage power supply apparatus according to claim 6, wherein said current detection circuit includes an included current detection circuit having sensitivity to a current variation of a low frequency, wherein said smoothing circuit is adapted to smooth the output of said current detection circuit.
- 8. A high voltage power supply apparatus according to claim 7, wherein said smoothing circuit includes a limiting circuit for limiting the voltage of the output signal of said current detection circuit.
- 9. A high voltage power supply apparatus that outputs a constant current or a constant voltage, comprising:a DC high voltage circuit for outputting a DC high voltage; a high voltage output circuit for superposing an AC high voltage with the DC output of said DC high voltage circuit, for supply to a charger load; a detection circuit for detecting a variation of low frequency characteristics in the output of said high voltage output circuit; and a comparator circuit for comparing each of the output of said detection circuit with the reference value and outputting a signal for lowering or terminating the output of said high voltage output circuit when the output of said detection circuit exceeds the reference value, wherein said detection circuit includes a limiting circuit for limiting the variation at the leading upshift in the DC output from said DC high voltage circuit.
- 10. A high voltage power supply apparatus according to claim 9, wherein said detection circuit includes a circuit for smoothing the output of said high voltage output circuit.
- 11. A high voltage power supply apparatus comprising:a high voltage output circuit for supplying a high constant voltage to a load; a detection circuit for detecting whether an average current flowed to the load is abnormal with respect to the load; and a controller for lowering or terminating the high constant voltage supplied by said high voltage output circuit when an abnormality is detected by said detection circuit.
- 12. A high voltage power supply apparatus according to claim 11, wherein said high voltage output circuit supplied a constant AC voltage.
- 13. A high voltage power supply apparatus according to claim 11, wherein said detection circuit detects the abnormality in accordance with the average current exceeding a predetermined current.
- 14. A high voltage power supply apparatus that outputs a constant current or a constant voltage, said apparatus comprising:a high voltage output circuit for supplying a charger load with a high voltage; a detection circuit for detecting an average of the output current of said high voltage output circuit; and a comparator circuit for comparing the output of said detection circuit with a reference value and outputting a signal for lowering or terminating the output of said high voltage output circuit when the output of said detection circuit exceeds the reference value.
Priority Claims (1)
Number |
Date |
Country |
Kind |
10-304833 |
Oct 1998 |
JP |
|
Parent Case Info
This is a divisional of Application Ser. No. 09/425,226, filed Oct. 22, 1999 now U.S. Pat. No. 6,515,841.
US Referenced Citations (5)