JP3468114B2 - High voltage power supply - Google Patents
High voltage power supplyInfo
- Publication number
- JP3468114B2 JP3468114B2 JP21725698A JP21725698A JP3468114B2 JP 3468114 B2 JP3468114 B2 JP 3468114B2 JP 21725698 A JP21725698 A JP 21725698A JP 21725698 A JP21725698 A JP 21725698A JP 3468114 B2 JP3468114 B2 JP 3468114B2
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- power supply
- voltage power
- current
- transformer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Description
【発明の詳細な説明】
【０００１】
【発明の属する技術分野】本発明は、電子写真装置の感
光体に電位を供給し、かつ極性切替えを可能とする高圧
電源装置に関するものである。
【０００２】
【従来の技術】従来この種の高圧電源装置は図３に示す
ように構成されていた。すなわち、図３において、１は
低圧の直流電源であり、この直流電源１には高圧トラン
ス１２の一次巻線１３とスイッチング素子１８が直列接
続されている。このスイッチング素子１８のベースには
制御回路１９が接続されており、この制御回路１９に
は、高圧トランス１２の電圧検出巻線２０に発生した電
圧をダイオード２１とコンデンサ２２で整流平滑した電
圧が帰還されている。
【０００３】上記高圧トランス１２の二次巻線１４には
ダイオード１５とコンデンサ１６と抵抗１７により構成
される整流、平滑及び放電回路が接続され、これにより
定電圧制御の第１の高圧電源が構成されている。
【０００４】又、直流電源１には高圧トランス２も接続
されており、この高圧トランス２の一次巻線３とスイッ
チング素子８が直列接続されている。
【０００５】上記スイッチング素子８のベースには制御
回路９が接続されており、この制御回路９には、出力端
子２５より負荷１１に流れる電流を検出する電流検出抵
抗１０で発生した電圧が帰還されている。
【０００６】上記高圧トランス２の二次巻線４にはダイ
オード５とコンデンサ６と抵抗７により構成される整
流、平滑及び放電回路が接続され、これにより低電流制
御の第２の高圧電源が構成されている。
【０００７】又、端子２３で制御回路９のオン、オフ動
作を行うことにより、第２の高圧電源をオン、オフし、
出力の極性を切替える構成となっている。
【０００８】
【発明が解決しようとする課題】しかしながら、このよ
うな従来の高圧電源装置では、第２の高圧電源の電流値
を正しく検出しようとするために、電流の流れるループ
には、他の電流が流れないように、第１の高圧電源の電
圧検出手段として、高圧トランス１２に電圧検出巻線２
０を設け、ダイオード２１とコンデンサ２２で整流、平
滑した電圧を制御回路１９に帰還する構成となってい
た。
【０００９】このような構成では、高圧トランス１２の
二次巻線１４と電圧検出巻線２０との結合係数や、二次
巻線１４のインピーダンスが有るため、負荷１１の変動
や、直流電源１の電圧変動により、第１の高圧電源の出
力電圧が変動する不具合があった。
【００１０】又、高圧トランス１２に、電圧検出巻線２
０を設けること及びダイオード２１とコンデンサ２２を
追加することにより、高圧電源装置が大型化するととも
にコスト面で不利になるものであった。
【００１１】本発明は以上のような従来の欠点を除去
し、簡単な構成で安定した出力電圧が得られ、かつ小型
で安価な高圧電源装置を提供することを目的とするもの
である。
【００１２】
【課題を解決するための手段】上記課題を解決するため
に本発明の高圧電源装置は、第１の高圧電源の電圧検出
を、二次側の出力を電圧検出抵抗で直接検出し、なおか
つ、電圧検出抵抗に流す電流値を、第２の高圧電源から
出力される電流値の絶対値より大きくするように構成し
たものである。
【００１３】この構成とすることにより、第２の高圧電
源の定電流精度を落とすことなく、第１の高圧電源の定
電圧精度を向上させ、かつ小型で安価とすることができ
る。
【００１４】
【発明の実施の形態】本発明の請求項１に記載の発明
は、直流電源をスイッチング素子でスイッチングし、高
圧トランスの一次側に印加し、この高圧トランスの二次
側に発生する交流出力を整流してなる直流高圧電源にお
いて、定電圧の高電圧を発生し、かつ連続的に動作させ
る第１の高圧電源と、この第１の高圧電源とは逆極性で
定電流の高電圧を発生し、かつ断続的に動作させる第２
の高圧電源を有し、前記第１の高圧電源の高圧トランス
の二次側の高圧側に、前記第２の高圧電源の高圧トラン
スの二次側の低圧側を接続する直列接続とし、前記第１
の高圧電源の高圧トランスの二次側には出力電圧を検出
するための電圧検出抵抗を設け、この電圧検出抵抗に発
生する電圧を前記第１の高圧電源の制御回路に帰還させ
ることにより前記第１の高圧電源を定電圧制御するとと
ともに、前記第１の高圧電源の高圧トランスの二次側の
低電位側と接地間に電流検出抵抗を設け、この電流検出
抵抗に発生する電圧を前記第２の高圧電源の制御回路に
帰還させることにより前記第２の高圧電源を定電流制御
し、前記電圧検出抵抗に流す電流を前記第２の高圧電源
から出力される出力電流の絶対値より大きくするように
構成したものであり、この構成により第２の高圧電源の
定電流精度を高くするとともに小型で安価とすることが
できる。
【００１５】以下、本発明の一実施の形態について図面
を用いて説明する。本発明の高圧電源装置の一実施の形
態について図１を用いて説明する。図１は本発明の一実
施の形態における高圧電源装置を示す回路図である。
【００１６】図１において、２６は低圧の直流電源で、
この直流電源２６には高圧トランス３７の一次巻線３８
とスイッチング素子４３が直列接続されている。上記ス
イッチング素子４３のベースには制御回路４４が接続さ
れており、この制御回路４４には、高圧トランス３７の
二次巻線３９で発生した交流出力をダイオード４０とコ
ンデンサ４１で整流、平滑された直流出力が電圧検出抵
抗４２で電圧を検出し制御回路４４に帰還されておりこ
れにより定電圧制御の第１の高圧電源が構成されてい
る。
【００１７】又、直流電源２６には、高圧トランス２７
も接続されており、この高圧トランス２７の一次巻線２
８とスイッチング素子３３が直列接続されている。
【００１８】上記スイッチング素子３３のベースには制
御回路３４が接続されており、この制御回路３４には、
出力端子４６より負荷３６に流れる電流を検出する電流
検出抵抗３５で発生した電圧が帰還されている。
【００１９】上記高圧トランス２７の二次巻線２９には
ダイオード３０とコンデンサ３１と放電抵抗３２により
整流、平滑及び放電回路が構成され、これにより定電流
制御の第２の高圧電源が構成されている。又端子４５で
制御回路３４のオン、オフ動作を行うことにより、第２
の高圧電源をオン、オフし出力の極性を切替える構成と
なっている。
【００２０】上記構成において、第１の高圧電源の電圧
検出手段は電圧検出抵抗４２を第１の高圧電源の二次側
の高圧側に接続し、この第１の高圧電源の電圧が一定で
あり、電圧検出抵抗４２に流れる電流も一定となる。次
に第２の高圧電源を端子４５でオンをすれば、出力端子
４６に発生する直流の極性は逆になり負荷３６に流れる
ことになる。
【００２１】ここで第１の高圧電源の電圧を−１０００
Ｖとし、電圧検出手抵抗を１０ＭΩと仮定すると、電圧
検出抵抗４２に流れる電流は−１０μＡとなる。この時
負荷３６に流れる電流は負荷のインピーダンスで決定さ
れる。
【００２２】次に第２の高圧電源をオンすると出力の極
性が切替わり＋となる。この時の必要な電流値が仮に＋
５μＡとするならば、電圧検出抵抗４２に流れる電流１
０μＡから、負荷３６に流れる電流５μＡと、電流検出
抵抗３５に流れる電流５μＡに分流する。
【００２３】このことを図２で説明する。定電圧電源の
検出抵抗に流れる電流ｉ1は常に一定であり、この電流
ｉ1は負荷３６に流れる電流ｉ2と電流検出抵抗３５に流
れる電流ｉ3に分流するので下記の式となる。
【００２４】ｉ1＝ｉ2＋ｉ3……式（１）
但し、ｉ1よりｉ2が大きくなるとｉ3に電流が流れなく
なり定電流制御もできなくなる。
【００２５】よって本発明は、電流ｉ1を基準電流とし
ｉ2との差の電流ｉ3を帰還することにより、定電流制御
とすることが可能である。
【００２６】
【発明の効果】以上のように本発明の高圧電源装置は構
成されるため、第１の高圧電源の電圧及び第２の高圧電
源の電流が精度よく出力され、しかも小型で安価なもの
とすることができ、産業的価値の大なるものである。Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a high-voltage power supply which supplies a potential to a photosensitive member of an electrophotographic apparatus and enables polarity switching. 2. Description of the Related Art Conventionally, this kind of high-voltage power supply device has been configured as shown in FIG. That is, in FIG. 3, reference numeral 1 denotes a low-voltage DC power supply, and a primary winding 13 and a switching element 18 of a high-voltage transformer 12 are connected to the DC power supply 1 in series. A control circuit 19 is connected to the base of the switching element 18, and a voltage obtained by rectifying and smoothing the voltage generated in the voltage detection winding 20 of the high-voltage transformer 12 by the diode 21 and the capacitor 22 is fed back to the control circuit 19. Have been. A rectifying, smoothing and discharging circuit composed of a diode 15, a capacitor 16 and a resistor 17 is connected to the secondary winding 14 of the high-voltage transformer 12, thereby forming a first high-voltage power supply of constant voltage control. Have been. A high voltage transformer 2 is also connected to the DC power supply 1, and a primary winding 3 of the high voltage transformer 2 and a switching element 8 are connected in series. A control circuit 9 is connected to the base of the switching element 8, and a voltage generated by a current detection resistor 10 for detecting a current flowing through a load 11 from an output terminal 25 is fed back to the control circuit 9. ing. A rectifying, smoothing and discharging circuit composed of a diode 5, a capacitor 6 and a resistor 7 is connected to the secondary winding 4 of the high-voltage transformer 2, thereby forming a second high-voltage power supply of low current control. Have been. Further, by turning on and off the control circuit 9 at the terminal 23, the second high-voltage power supply is turned on and off,
The output polarity is switched. However, in such a conventional high-voltage power supply device, in order to correctly detect the current value of the second high-voltage power supply, the loop through which the current flows is provided with another current. As a means for detecting the voltage of the first high-voltage power supply, the voltage detection winding 2 is connected to the high-voltage transformer 12 so that no current flows.
0 is provided, and the voltage rectified and smoothed by the diode 21 and the capacitor 22 is fed back to the control circuit 19. In such a configuration, since the coupling coefficient between the secondary winding 14 of the high-voltage transformer 12 and the voltage detection winding 20 and the impedance of the secondary winding 14 are present, fluctuations in the load 11 and the DC power supply 1 There is a problem that the output voltage of the first high-voltage power supply fluctuates due to the above voltage fluctuation. A high voltage transformer 12 has a voltage detecting winding 2
The provision of 0 and the addition of the diode 21 and the capacitor 22 increase the size of the high-voltage power supply device and are disadvantageous in cost. SUMMARY OF THE INVENTION An object of the present invention is to provide a small and inexpensive high-voltage power supply which can eliminate the above-mentioned drawbacks of the prior art, can obtain a stable output voltage with a simple structure, and can provide a small and inexpensive power supply. In order to solve the above problems, a high voltage power supply according to the present invention detects a voltage of a first high voltage power supply by directly detecting an output on a secondary side by a voltage detection resistor. Further, the current flowing through the voltage detection resistor is configured to be larger than the absolute value of the current output from the second high-voltage power supply. With this configuration, it is possible to improve the constant voltage accuracy of the first high-voltage power supply without lowering the constant current accuracy of the second high-voltage power supply, and to reduce the size and cost. According to the first aspect of the present invention, a DC power supply is switched by a switching element, applied to a primary side of a high voltage transformer, and generated on a secondary side of the high voltage transformer. A first high-voltage power supply that generates a constant high voltage and continuously operates in a DC high-voltage power supply obtained by rectifying an AC output, and a high voltage of a constant current having a polarity opposite to that of the first high-voltage power supply. And the second that operates intermittently
A high-voltage power supply of the first high-voltage power supply, and a high-voltage side of the secondary of the second high-voltage power supply is connected in series to a high-voltage side of the high-voltage transformer of the second high-voltage power supply; 1
Of the secondary side of the high voltage transformer of the high-voltage power supply is provided a voltage detection resistor for detecting the output voltage, originating in the voltage detection resistor
The generated voltage is fed back to the control circuit of the first high-voltage power supply.
To control the first high-voltage power supply at a constant voltage.
In both cases, a current detecting resistor is provided between the low-potential side on the secondary side of the high-voltage transformer of the first high-voltage power supply and the ground, and the voltage generated at this current detecting resistor is fed back to the control circuit of the second high-voltage power supply . Constant current control of the second high-voltage power supply
And a current flowing through the voltage detection resistor is supplied to the second high-voltage power supply.
The configuration is such that the absolute value of the output current output from the second high-voltage power supply is larger than that of the second high-voltage power supply. An embodiment of the present invention will be described below with reference to the drawings. One embodiment of the high voltage power supply of the present invention will be described with reference to FIG. FIG. 1 is a circuit diagram showing a high-voltage power supply device according to one embodiment of the present invention. In FIG. 1, reference numeral 26 denotes a low-voltage DC power supply.
This DC power supply 26 has a primary winding 38 of a high voltage transformer 37.
And the switching element 43 are connected in series. A control circuit 44 is connected to the base of the switching element 43. The control circuit 44 rectifies and smoothes the AC output generated in the secondary winding 39 of the high-voltage transformer 37 by the diode 40 and the capacitor 41. The DC output is detected by the voltage detection resistor 42 and is fed back to the control circuit 44, thereby forming a first high-voltage power supply of constant voltage control. The DC power supply 26 includes a high-voltage transformer 27.
Is connected to the primary winding 2 of the high-voltage transformer 27.
8 and the switching element 33 are connected in series. A control circuit 34 is connected to the base of the switching element 33. The control circuit 34
The voltage generated by the current detection resistor 35 for detecting the current flowing to the load 36 from the output terminal 46 is fed back. In the secondary winding 29 of the high-voltage transformer 27, a rectifying, smoothing and discharging circuit is formed by a diode 30, a capacitor 31, and a discharge resistor 32, thereby forming a second high-voltage power supply of constant current control. I have. The control circuit 34 is turned on and off at the terminal 45, so that the second
The high voltage power supply is turned on and off to switch the output polarity. In the above configuration, the voltage detecting means of the first high-voltage power supply connects the voltage detecting resistor 42 to the secondary high-voltage side of the first high-voltage power supply, and the voltage of the first high-voltage power supply is constant. , The current flowing through the voltage detection resistor 42 is also constant. Next, when the second high-voltage power supply is turned on at the terminal 45, the polarity of the direct current generated at the output terminal 46 is reversed and flows to the load 36. Here, the voltage of the first high-voltage power supply is set to -1000.
Assuming that the voltage is V and the voltage detection hand resistance is 10 MΩ, the current flowing through the voltage detection resistor 42 is −10 μA. At this time, the current flowing through the load 36 is determined by the impedance of the load. Next, when the second high-voltage power supply is turned on, the polarity of the output is switched to +. If the required current value at this time is +
If it is 5 μA, the current 1 flowing through the voltage detection resistor 42
The current is shunted from 0 μA into a current 5 μA flowing through the load 36 and a current 5 μA flowing through the current detection resistor 35. This will be described with reference to FIG. The current i 1 flowing through the detection resistor of the constant voltage power supply is always constant, and this current i 1 is divided into the current i 2 flowing through the load 36 and the current i 3 flowing through the current detection resistor 35, so that the following equation is obtained. I 1 = i 2 + i 3 (1) However, if i 2 is larger than i 1 , no current flows through i 3 and constant current control cannot be performed. Thus, in the present invention, constant current control can be performed by using the current i 1 as a reference current and feeding back the current i 3 having a difference from i 2 . As described above, since the high-voltage power supply of the present invention is constructed, the voltage of the first high-voltage power supply and the current of the second high-voltage power supply are output with high accuracy, and are small and inexpensive. And of great industrial value.
【図面の簡単な説明】
【図１】本発明の高圧電源装置の一実施の形態における
回路図
【図２】同一実施の形態における電流の流れを詳細にし
た回路図
【図３】従来の高圧電源装置の回路図
【符号の説明】
２６ 直流電源
２７ 高圧トランス
２８ 一次巻線
２９ 二次巻線
３０ ダイオード
３１ コンデンサ
３２ 放電抵抗
３３ スイッチング素子
３４ 制御回路
３５ 電流検出抵抗
３６ 負荷
３７ 高圧トランス
３８ 一次巻線
３９ 二次巻線
４０ ダイオード
４１ コンデンサ
４２ 電圧検出抵抗
４３ スイッチング素子
４４ 制御回路
４５ 端子
４６ 出力端子BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram of an embodiment of a high-voltage power supply device according to the present invention; FIG. 2 is a circuit diagram showing details of a current flow in the same embodiment; FIG. 26 DC power supply 27 High voltage transformer 28 Primary winding 29 Secondary winding 30 Diode 31 Capacitor 32 Discharge resistor 33 Switching element 34 Control circuit 35 Current detection resistor 36 Load 37 High voltage transformer 38 Primary winding Wire 39 Secondary winding 40 Diode 41 Capacitor 42 Voltage detection resistor 43 Switching element 44 Control circuit 45 Terminal 46 Output terminal
Claims (1)
ングし、高圧トランスの一次側に印加し、この高圧トラ
ンスの二次側に発生する交流出力を整流してなる直流高
圧電源において、定電圧の高電圧を発生し、かつ連続的
に動作させる第１の高圧電源と、この第１の高圧電源と
は逆極性で定電流の高電圧を発生し、かつ断続的に動作
させる第２の高圧電源を有し、前記第１の高圧電源の高
圧トランスの二次側の高圧側に、前記第２の高圧電源の
高圧トランスの二次側の低圧側を接続する直列接続と
し、前記第１の高圧電源の高圧トランスの二次側には出
力電圧を検出するための電圧検出抵抗を設け、この電圧
検出抵抗に発生する電圧を前記第１の高圧電源の制御回
路に帰還させることにより前記第１の高圧電源を定電圧
制御するととともに、前記第１の高圧電源の高圧トラン
スの二次側の低電位側と接地間に電流検出抵抗を設け、
この電流検出抵抗に発生する電圧を前記第２の高圧電源
の制御回路に帰還させることにより前記第２の高圧電源
を定電流制御し、前記電圧検出抵抗に流す電流を前記第
２の高圧電源から出力される出力電流の絶対値より大き
くするように構成した高圧電源装置。(57) [Claims 1] DC power obtained by switching a DC power supply with a switching element, applying the DC power supply to a primary side of a high voltage transformer, and rectifying an AC output generated on a secondary side of the high voltage transformer. A first high-voltage power supply for generating a high voltage of a constant voltage and operating continuously in the high-voltage power supply; and generating a high-voltage of a constant current having a polarity opposite to that of the first high-voltage power supply, and intermittently. A second high-voltage power supply to be operated; a series connection for connecting a secondary low-voltage side of the high-voltage transformer of the second high-voltage power supply to a secondary high-voltage side of the high-voltage transformer of the first high-voltage power supply; and then, the first of the secondary side of the high voltage transformer of the high-voltage power supply is provided a voltage detection resistor for detecting the output voltage, the voltage
The voltage generated at the detection resistor is controlled by the control circuit of the first high-voltage power supply.
The first high-voltage power supply to a constant voltage
Controlling and providing a current detection resistor between the low potential side on the secondary side of the high voltage transformer of the first high voltage power supply and the ground,
The voltage generated at the current detection resistor is fed back to the control circuit for the second high-voltage power supply, thereby providing the second high-voltage power supply.
And the current flowing through the voltage detection resistor is
2 is larger than the absolute value of the output current output from the high-voltage power supply
A high-voltage power supply device configured to operate .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21725698A JP3468114B2 (en) | 1998-07-31 | 1998-07-31 | High voltage power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21725698A JP3468114B2 (en) | 1998-07-31 | 1998-07-31 | High voltage power supply |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000050628A JP2000050628A (en) | 2000-02-18 |
| JP3468114B2 true JP3468114B2 (en) | 2003-11-17 |
Family
ID=16701302
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21725698A Expired - Lifetime JP3468114B2 (en) | 1998-07-31 | 1998-07-31 | High voltage power supply |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3468114B2 (en) |
-
1998
- 1998-07-31 JP JP21725698A patent/JP3468114B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2000050628A (en) | 2000-02-18 |
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