JPH0759347A - Switching power supply circuit - Google Patents
Switching power supply circuitInfo
- Publication number
- JPH0759347A JPH0759347A JP20232593A JP20232593A JPH0759347A JP H0759347 A JPH0759347 A JP H0759347A JP 20232593 A JP20232593 A JP 20232593A JP 20232593 A JP20232593 A JP 20232593A JP H0759347 A JPH0759347 A JP H0759347A
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- Prior art keywords
- voltage
- circuit
- output
- power supply
- control system
- Prior art date
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明はスイッチング電源回路に
関し、特にクロスレギュレーションにおける非制御系出
力電圧安定化回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching power supply circuit, and more particularly to a non-control system output voltage stabilizing circuit in cross regulation.
【０００２】[0002]
【従来の技術】図３は従来のスイッチング電源の一例の
回路図である。2. Description of the Related Art FIG. 3 is a circuit diagram of an example of a conventional switching power supply.
【０００３】このスイッチング電源は直流電源１と、変
圧器４と、変圧器４に流れる電流をスイッチングするメ
インスイッチと、該スイッチイングを制御する制御回路
２と、変圧器４の第１の二次巻線、ダイオード５、出力
コンデンサ７からなる非制御系出力回路と、変圧器４の
第２の二次巻線、ダイオード６、出力コンデンサ８から
なる制御系出力回路と、誤差検出部１６と、疑似負荷接
続制御部１７と、制御系出力回路の出力電圧の偏差を調
整するためのフイードバック回路とからなる。This switching power supply includes a DC power supply 1, a transformer 4, a main switch for switching a current flowing through the transformer 4, a control circuit 2 for controlling the switching, and a first secondary of the transformer 4. A non-control system output circuit including a winding, a diode 5, and an output capacitor 7, a control system output circuit including a second secondary winding of the transformer 4, a diode 6, and an output capacitor 8, and an error detector 16. It comprises a pseudo load connection control section 17 and a feedback circuit for adjusting the deviation of the output voltage of the control system output circuit.
【０００４】フィードバック回路は、制御系出力回路の
出力電圧を分流するための抵抗１０、１１と、基準電圧
を保持する直流電源１３と、制御系出力電圧を抵抗１１
の電位を一方の端子に、基準電圧を他方の端子に入力さ
れるオペアンプ１４とからなる。もし、非制御系出力回
路と制御系出力回路の出力電圧間にクロスレギュレーシ
ョンが発生すると、誤差検出部１６がこれを検出し、そ
の検出により疑似負荷接続制御部１７が非制御系か制御
系かの軽負荷の方の回路に疑似負荷を接続してクロスレ
ギュレーションの軽減を図るようになっていた。The feedback circuit includes resistors 10 and 11 for shunting the output voltage of the control system output circuit, a DC power supply 13 for holding a reference voltage, and a resistor 11 for the control system output voltage.
Of the operational amplifier 14 whose potential is input to one terminal and reference voltage is input to the other terminal. If cross regulation occurs between the output voltages of the non-control system output circuit and the control system output circuit, the error detection unit 16 detects this and whether the pseudo load connection control unit 17 is the non-control system or the control system based on the detection. It was designed to reduce the cross regulation by connecting a pseudo load to the light load circuit.
【０００５】上記のように、従来、この種のスイッチン
グ電源は、２つの出力系の電圧差と、その電圧差の基準
電圧との誤差を検出し、負荷の不均衡変動が大きくなっ
て前記誤差がある限度を超えた場合にこれを判別して軽
負荷側の出力に疑似負荷を接続する疑似負荷接続により
２つの出力の均衡を図るようにしていた。この点につい
ては特開昭６３ー１９４５６７号に記載されている。As described above, conventionally, this type of switching power supply detects an error between the voltage difference between the two output systems and the reference voltage of the voltage difference, and the unbalance fluctuation of the load becomes large, resulting in the error. When a certain limit is exceeded, this is discriminated and a pseudo load is connected to the output on the light load side so as to balance the two outputs. This point is described in JP-A-63-194567.
【０００６】[0006]
【発明が解決しようとする課題】上述した従来のスイッ
チング電源は、非制御系の出力電圧を安定化させるため
に、両出力の電圧差と、該電圧差と基準電圧との誤差を
検出し、軽負荷側の出力に疑似負荷を接続し出力の均衡
を図っているため、効率が悪くなるという欠点がある。
本発明の目的は、２つの出力系の負荷に不均衡になるク
ロスレギュレーションが生じても疑似負荷を接続するこ
となく出力の均衡が図れるスイッチング電源回路を提供
することである。The conventional switching power supply described above detects the voltage difference between both outputs and the error between the voltage difference and the reference voltage in order to stabilize the output voltage of the non-control system. Since a pseudo load is connected to the output on the light load side to balance the outputs, there is a drawback in that efficiency is reduced.
An object of the present invention is to provide a switching power supply circuit that can balance outputs without connecting a pseudo load even if cross regulation occurs in which loads of two output systems become unbalanced.
【０００７】[0007]
【課題を解決するための手段】本発明のスイッチング電
源回路は、直流電源と、該直流電源に直列に接続された
変圧器と、スイッチング素子と、スイッチングの制御回
路と、前記変圧器の二次巻線に接続された制御系と非制
御系の二つの出力系を有するスイッチング電源におい
て、制御系出力回路の出力電流を検出する電流検出回路
と、該電流検出回路が検出した電流に応じて変圧器の一
次電圧を変化させる制御電圧制御手段を有する。A switching power supply circuit of the present invention includes a DC power supply, a transformer connected in series to the DC power supply, a switching element, a switching control circuit, and a secondary of the transformer. In a switching power supply that has two output systems, a control system and a non-control system, connected to a winding, a current detection circuit that detects the output current of the control system output circuit, and a transformer that responds to the current detected by the current detection circuit. And a control voltage control means for changing the primary voltage of the container.
【０００８】また、前記電流検出回路が、検出した電流
に応じたレベルの電流検出信号を出力し、前記電圧制御
手段が前記電流検出信号により制御系出力回路の電圧を
基準電圧と比較して変圧器の一次電圧を制御し、非制御
系出力回路の出力の変動を抑制するものが望ましく、さ
らに、前記電圧制御手段が、制御電圧変更回路と、前記
制御回路とからなり、制御電圧変更回路が前記電流検出
信号により電圧が変化する電圧可変器と、基準電圧出力
手段と、前記電圧可変器の基準電圧との差分を所定の比
率で出力する誤差増幅器とからなり、前記制御回路が前
記誤差増幅器の出力によって変圧器の一次電流を制御す
るもの、および、前記電圧可変器が制御系出力回路の出
力端子に抵抗と直列に接続され、また、前記誤差増幅器
の一方の端子には前記抵抗の一部を含む前記電圧可変器
が前記制御系の出力電圧の分圧された状態で接続され、
他方の端子に基準電圧出力手段が接続されたものも本発
明に含まれる。Further, the current detection circuit outputs a current detection signal of a level corresponding to the detected current, and the voltage control means compares the voltage of the control system output circuit with a reference voltage by the current detection signal and transforms the voltage. It is desirable to control the primary voltage of the controller to suppress the fluctuation of the output of the non-control system output circuit. Furthermore, the voltage control means includes a control voltage changing circuit and the control circuit, and the control voltage changing circuit is The control circuit includes a voltage variable device whose voltage changes according to the current detection signal, a reference voltage output means, and an error amplifier which outputs a difference between the reference voltage of the voltage variable device at a predetermined ratio. That controls the primary current of the transformer by the output of the voltage regulator, and the voltage regulator is connected to the output terminal of the control system output circuit in series with a resistor, and one terminal of the error amplifier is It said voltage variator comprising a portion of the serial resistor is connected in the divided state of the output voltage of the control system,
The present invention also includes a reference voltage output means connected to the other terminal.
【０００９】[0009]
【作用】制御出力回路の出力電流が増加するのは、非制
御出力回路側で発生した負荷条件によって変圧器の一次
電圧が高くなったためなので一次電圧を下げなければな
らない。制御出力回路の出力電流が減少したときは、そ
の反対である。したがって、制御系出力電流が増加する
と電圧を下げ、減少すると電圧を高くするフィードバッ
クを設定することにより、非制御系出力電流と電圧の関
係を安定化することができる。The output current of the control output circuit increases because the primary voltage of the transformer increases due to the load condition generated on the non-control output circuit side, and therefore the primary voltage must be decreased. The opposite is true when the output current of the control output circuit decreases. Therefore, it is possible to stabilize the relationship between the non-control system output current and the voltage by setting the feedback that lowers the voltage when the control system output current increases and increases the voltage when the control system output current decreases.
【００１０】[0010]
【実施例】次に、本発明の実施例について図面を参照し
て説明する。Embodiments of the present invention will now be described with reference to the drawings.
【００１１】図１は本発明のスイッチング電源回路の一
実施例の回路図である。FIG. 1 is a circuit diagram of an embodiment of the switching power supply circuit of the present invention.
【００１２】このスイッチング電源は、直流電源１と、
変圧器４と、スイッチングを行うトランジスタからなる
メインスイッチ３と、メインスイッチ３のスイッチング
を制御する制御系回路２と、非制御系出力回路１８と、
制御系出力回路１９と、制御電圧変更回路１５を有して
いる。This switching power supply includes a DC power supply 1 and
A transformer 4, a main switch 3 composed of a transistor for switching, a control system circuit 2 for controlling switching of the main switch 3, a non-control system output circuit 18,
It has a control system output circuit 19 and a control voltage changing circuit 15.
【００１３】非制御系出力回路１８は、変圧器の第１の
二次巻線と、これに直列に接続されたダイオード５と、
出力端子に並列に接続された出力コンデンサ７とからな
り、所定の負荷が接続される。制御系出力回路１９は、
変圧器４の第２の二次巻線と、これに直列に接続された
ダイオード６と、出力端子に並列に接続された出力コン
デンサ８と、電流検出器９からなる。電流検出器９は、
制御系出力回路１９の出力電流を検出し、かつ、検出し
た電流に応じたレベルの信号を出力する。The non-control system output circuit 18 includes a first secondary winding of the transformer, a diode 5 connected in series with the first secondary winding, and
An output capacitor 7 connected in parallel to the output terminal is connected to a predetermined load. The control system output circuit 19 is
It comprises a second secondary winding of the transformer 4, a diode 6 connected in series with the second secondary winding, an output capacitor 8 connected in parallel to the output terminal, and a current detector 9. The current detector 9 is
The output current of the control system output circuit 19 is detected, and a signal of a level corresponding to the detected current is output.
【００１４】制御電圧変更回路１５は、電流検出器９の
出力信号を入力とし、電流検出器９が出力した信号に対
応する電圧を発生する電圧可変器１２と、制御系出力回
路１９の出力端子間に電圧可変器１２とともにそれに直
列に接続された抵抗１０、１１と、基準電圧を出力する
直流電源１３と、制御系出力回路の出力電圧のなかで電
圧可変器１２と抵抗１１とからなる電圧を一方の端子
に、直流電源１３の電圧を他方の端子に入力され、出力
を制御回路２へ入力する誤差増幅器１４とからなる。The control voltage changing circuit 15 receives the output signal of the current detector 9 as an input and generates a voltage corresponding to the signal output by the current detector 9, and a voltage variable device 12 and an output terminal of the control system output circuit 19. A voltage consisting of a voltage variable device 12 and a resistor 11 connected in series with the voltage variable device 12, a DC power source 13 for outputting a reference voltage, and the output voltage of the control system output circuit. Is input to one terminal and the voltage of the DC power supply 13 is input to the other terminal, and the error amplifier 14 inputs the output to the control circuit 2.
【００１５】次に、本実施例の動作について説明する。Next, the operation of this embodiment will be described.
【００１６】図２は本実施例の制御系出力回路の出力電
流と非制御系出力回路１８の出力電圧との関係を示す図
である。FIG. 2 is a diagram showing the relationship between the output current of the control system output circuit and the output voltage of the non-control system output circuit 18 of this embodiment.
【００１７】本実施例は、制御系出力回路１９の出力電
流が増加すると、電流検出器９がこの電流増加を検出
し、その検出信号によって制御電圧変更回路１５の電圧
可変器１２の電圧を高くする。この電圧増加により増加
した電圧可変器１２と抵抗１１とでなす電圧と基準電圧
との差が誤差増幅器１４から制御回路２に入力され、そ
れによる制御回路２の制御により変圧器４の出力電圧が
低下されて、非制御系出力回路１８の出力も低下する。
また、電流検出器９が制御系出力回路１９の出力電流の
減少を検出した場合は、この反対で、誤差増幅器１４か
らの入力により変圧器４の電圧が上昇され、非制御系出
力回路１８の出力電圧も上昇される。In the present embodiment, when the output current of the control system output circuit 19 increases, the current detector 9 detects this increase in current, and the voltage of the voltage variable unit 12 of the control voltage changing circuit 15 is increased by the detection signal. To do. The difference between the voltage formed by the voltage variable device 12 and the resistor 11 and the reference voltage, which is increased by this voltage increase, is input from the error amplifier 14 to the control circuit 2 and the output voltage of the transformer 4 is controlled by the control of the control circuit 2. As a result, the output of the non-control system output circuit 18 also decreases.
On the contrary, when the current detector 9 detects the decrease of the output current of the control system output circuit 19, the voltage of the transformer 4 is increased by the input from the error amplifier 14, and the non-control system output circuit 18 outputs. The output voltage is also increased.
【００１８】この動作をまとめて特性曲線にすると、図
２に示すようになる。特性曲線２１は、制御系出力回路
１９の出力電流と電圧との関係が曲線２４に示すように
なるように変圧器４の一次電圧を制御することによって
非制御系出力回路の出力電圧が示す値である。また、特
性曲線２２は、制御系出力回路１９の出力電流と電圧と
の関係を曲線２３のようにした場合に、非制御系出力回
路１８の出力電圧が示す値である。したがって、制御回
路２の制御を制御系回路の電流電圧関係が曲線２４に示
すようになるように設定することによって特性曲線２１
に見られるように、非制御系出力回路１８の出力電圧を
図２に示すＶ1とＶ2の範囲内に安定化させることができ
る。FIG. 2 shows a characteristic curve of this operation. The characteristic curve 21 is a value indicated by the output voltage of the non-control system output circuit by controlling the primary voltage of the transformer 4 so that the relationship between the output current and the voltage of the control system output circuit 19 becomes as shown by the curve 24. Is. Further, the characteristic curve 22 is a value indicated by the output voltage of the non-control system output circuit 18 when the relationship between the output current of the control system output circuit 19 and the voltage is set as the curve 23. Therefore, the characteristic curve 21 is set by setting the control of the control circuit 2 so that the current-voltage relationship of the control system circuit becomes as shown by the curve 24.
As can be seen from the above, the output voltage of the non-control system output circuit 18 can be stabilized within the range of V 1 and V 2 shown in FIG.
【００１９】[0019]
【発明の効果】以上説明したように本発明は、制御系出
力回路の出力電流の変化を監視して、二次電圧が一定に
なるように変圧器４が出力電圧を制御するので、従来の
疑似負荷を接続することに比較して電力の浪費がなくな
り、効率のよいスイッチング電源が実現できるという効
果がある。As described above, according to the present invention, the transformer 4 controls the output voltage so that the secondary voltage becomes constant by monitoring the change in the output current of the control system output circuit. Compared to connecting a pseudo load, there is an effect that power consumption is reduced and an efficient switching power supply can be realized.
【図１】本発明のスイッチング電源回路の一実施例の回
路図である。FIG. 1 is a circuit diagram of an embodiment of a switching power supply circuit of the present invention.
【図２】図１に示すスイッチング電源回路の特性曲線で
ある。FIG. 2 is a characteristic curve of the switching power supply circuit shown in FIG.
【図３】従来のスイッチング電源回路の一例の回路図で
ある。FIG. 3 is a circuit diagram of an example of a conventional switching power supply circuit.
１ 直流電源 ２ 制御回路 ３ メインスイッチ ４ 変圧器 ５ ダイオード ６ ダイオード ７ 出力コンデンサ ８ 出力コンデンサ ９ 電流検出器 １０ 抵抗 １１ 抵抗 １２ 電圧可変器 １３ 直流電源 １４ 誤差増幅器 １５ 制御電圧変更回路 １６ 誤差検出部 １７ 疑似負荷接続制御部 １８ 非制御系出力回路 １９ 制御系出力回路 ２１ 非制御系出力回路の出力特性曲線 ２２ 非制御系出力回路の出力特性曲線 ２３ 制御系出力回路の出力曲線 ２４ 制御系出力回路の出力曲線 1 DC Power Supply 2 Control Circuit 3 Main Switch 4 Transformer 5 Diode 6 Diode 7 Output Capacitor 8 Output Capacitor 9 Current Detector 10 Resistor 11 Resistor 12 Voltage Regulator 13 DC Power Supply 14 Error Amplifier 15 Control Voltage Change Circuit 16 Error Detection Section 17 Pseudo load connection control section 18 Non-control system output circuit 19 Control system output circuit 21 Output characteristic curve of non-control system output circuit 22 Output characteristic curve of non-control system output circuit 23 Output curve of control system output circuit 24 Control system output circuit Output curve
Claims (4)
れた変圧器と、スイッチング素子と、スイッチングの制
御回路と、該変圧器の二次巻線に接続された制御系と非
制御系の二つの出力系を有するスイッチング電源におい
て、 制御系出力回路の出力電流を検出する電流検出回路と、 該電流検出回路が検出した電流に応じて変圧器の一次電
圧を変化させる制御電圧制御手段を有することを特徴と
するスイッチング電源回路。1. A DC power supply, a transformer connected in series to the DC power supply, a switching element, a switching control circuit, and a control system and a non-control system connected to a secondary winding of the transformer. In a switching power supply having two output systems, a current detection circuit that detects the output current of the control system output circuit, and a control voltage control means that changes the primary voltage of the transformer according to the current detected by the current detection circuit. A switching power supply circuit having.
たレベルの電流検出信号を出力し、 前記電圧制御手段が、前記電流検出信号により制御系出
力回路の電圧を基準電圧と比較して変圧器の一次電圧を
制御し、非制御系出力回路の出力の変動を抑制する請求
項１記載のスイッチング電源回路。2. A current detection signal of a level according to the current detected by the current detection circuit is output, and the voltage control means compares the voltage of the control system output circuit with a reference voltage by the current detection signal and transforms the voltage. 2. The switching power supply circuit according to claim 1, wherein the primary voltage of the switching device is controlled to suppress fluctuations in the output of the non-control system output circuit.
と、前記制御回路とからなり、該制御電圧変更回路が前
記電流検出信号により電圧が変化する電圧可変器と、基
準電圧出力手段と、前記電圧可変器の基準電圧との差分
を所定の比率で出力する誤差増幅器とからなり、前記制
御回路が前記誤差増幅器の出力によって変圧器の一次電
流を制御する請求項２記載のスイッチング電源回路。3. The voltage control means comprises a control voltage changing circuit and the control circuit, the control voltage changing circuit changing the voltage according to the current detection signal, and a reference voltage output means. 3. The switching power supply circuit according to claim 2, comprising an error amplifier that outputs a difference from the reference voltage of the voltage changer at a predetermined ratio, and the control circuit controls the primary current of the transformer by the output of the error amplifier.
端子に抵抗と直列に接続され、また、前記誤差増幅器の
一方の端子には、前記抵抗の一部と電圧可変器が前記制
御系の出力電圧の分圧された状態で接続され、他方の端
子に基準電圧出力手段が接続された請求項３に記載のス
イッチング電源回路。4. The voltage variable device is connected in series with a resistor to an output terminal of a control system output circuit, and a part of the resistor and the voltage variable device are connected to the control system at one terminal of the error amplifier. 4. The switching power supply circuit according to claim 3, wherein the output voltage is connected in a divided state, and the reference voltage output means is connected to the other terminal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5202325A JP2679581B2 (en) | 1993-08-16 | 1993-08-16 | Switching power supply circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5202325A JP2679581B2 (en) | 1993-08-16 | 1993-08-16 | Switching power supply circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0759347A true JPH0759347A (en) | 1995-03-03 |
| JP2679581B2 JP2679581B2 (en) | 1997-11-19 |
Family
ID=16455686
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5202325A Expired - Lifetime JP2679581B2 (en) | 1993-08-16 | 1993-08-16 | Switching power supply circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2679581B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8988899B2 (en) | 2010-02-03 | 2015-03-24 | Honda Motor Co., Ltd. | Switching regulator device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58141678A (en) * | 1982-02-16 | 1983-08-23 | Canon Inc | High voltage power source |
-
1993
- 1993-08-16 JP JP5202325A patent/JP2679581B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58141678A (en) * | 1982-02-16 | 1983-08-23 | Canon Inc | High voltage power source |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8988899B2 (en) | 2010-02-03 | 2015-03-24 | Honda Motor Co., Ltd. | Switching regulator device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2679581B2 (en) | 1997-11-19 |
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