JPH0270265A - Switching power supply - Google Patents
Switching power supplyInfo
- Publication number
- JPH0270265A JPH0270265A JP21933788A JP21933788A JPH0270265A JP H0270265 A JPH0270265 A JP H0270265A JP 21933788 A JP21933788 A JP 21933788A JP 21933788 A JP21933788 A JP 21933788A JP H0270265 A JPH0270265 A JP H0270265A
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- output
- circuit
- power supply
- switching power
- 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.)
- Pending
Links
- 238000001514 detection method Methods 0.000 claims description 17
- 230000010355 oscillation Effects 0.000 claims description 7
- 230000007423 decrease Effects 0.000 abstract description 8
- 238000009499 grossing Methods 0.000 abstract description 7
- 238000006243 chemical reaction Methods 0.000 abstract description 5
- 230000002159 abnormal effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000007257 malfunction Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明はスイッチング電源装置に関し、特に過電圧検出
回路を有するスイッチング電源装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a switching power supply device, and more particularly to a switching power supply device having an overvoltage detection circuit.
従来、スイッチング電源装置においては、過電圧検出回
路はスイッチング電源の出力電圧を検出していた。Conventionally, in a switching power supply, an overvoltage detection circuit detects the output voltage of the switching power supply.
従来のスイッチング電源装置では、過電圧検出回路はス
イッチング電源の出力電圧を検出し、出力電圧がある一
定電圧以上になった場合に初めて動作してスイッチング
電源の動作を停止させるので、負荷には必ずある一定電
圧以上の過電圧が印加される。また負荷に許容される最
大印加電圧よりも低く、かつスイッチング電源の出力電
圧変動およびノイズ電圧等によって誤動作しないように
スイッチング電源の出力電圧よりある程度高い電圧の範
囲内で過電圧を検出しなければならないため精度の高い
部品を使用する必要があるので過電圧検出回路が高価に
なる。さらに過電圧を検出してから実際にスイッチング
電源の動作が停止するまでの遅れ時間があまり長いと、
過電圧検出電圧よりも出力電圧が更に上昇し、負荷の許
容最大印加電圧を越える場合が生じる等の欠点がある。In conventional switching power supplies, the overvoltage detection circuit detects the output voltage of the switching power supply and operates only when the output voltage exceeds a certain voltage to stop the operation of the switching power supply, so there is always an overvoltage detection circuit in the load. An overvoltage higher than a certain voltage is applied. In addition, overvoltage must be detected within a voltage range that is lower than the maximum applied voltage allowed by the load and somewhat higher than the output voltage of the switching power supply to prevent malfunctions due to output voltage fluctuations, noise voltage, etc. of the switching power supply. The overvoltage detection circuit becomes expensive because it requires the use of highly accurate components. Furthermore, if the delay between detecting overvoltage and when the switching power supply actually stops operating is too long,
There are drawbacks such as the output voltage rising further than the overvoltage detection voltage and exceeding the allowable maximum applied voltage of the load.
本発明のスイッチング電源装置は、出力電圧と基準電圧
との差を増幅する誤差増幅器と、前記誤差増幅器の出力
電圧と発振回路の出力電圧とを比較してパルスを得るパ
ルス幅変調回路と、前記パルス幅変調回路の出力パルス
によって駆動されるスイッチング素子とを備えるスイッ
チング電源装置において、前記誤差増幅器の出力電圧を
検出する検出回路を有し、前記検出回路の検出電圧があ
る一定電圧以上あるいは一定電圧以下になったときに前
記スイッチング電源装置の動作を停止させることを特徴
とする。The switching power supply device of the present invention includes: an error amplifier that amplifies the difference between an output voltage and a reference voltage; a pulse width modulation circuit that obtains a pulse by comparing the output voltage of the error amplifier and the output voltage of an oscillation circuit; A switching power supply device comprising a switching element driven by an output pulse of a pulse width modulation circuit, further comprising a detection circuit for detecting the output voltage of the error amplifier, wherein the detection voltage of the detection circuit is equal to or higher than a certain voltage or a certain voltage. The switching power supply device is characterized in that the operation of the switching power supply device is stopped when the following conditions occur.
次に、本発明について図面を参照して説明する。 Next, the present invention will be explained with reference to the drawings.
第１図は本発明のスイッチング電源装置の一実施例を示
す回路図である。FIG. 1 is a circuit diagram showing an embodiment of the switching power supply device of the present invention.
入力電源１は電圧変換用トランス２を介してスイッチン
グ素子３に接続されている。電圧変換用トランス２の二
次側は整流平滑回路を経て負荷５に接続される。スイッ
チング電源装置の出力電圧は抵抗６．７で分圧され、誤
差増幅器８の入力に接続され、誤差増幅器８の片方の入
力には基準電圧９が接続されている。誤差増幅器８の出
力と発振回路１０の出力はパルス幅変調回路１１に入力
され、パルス幅変調回路１１の出力は駆動回路１２を介
してスイッチング素子３に接続されている。An input power source 1 is connected to a switching element 3 via a voltage conversion transformer 2. The secondary side of the voltage conversion transformer 2 is connected to a load 5 via a rectifying and smoothing circuit. The output voltage of the switching power supply device is divided by a resistor 6.7 and connected to the input of an error amplifier 8, and one input of the error amplifier 8 is connected to a reference voltage 9. The output of the error amplifier 8 and the output of the oscillation circuit 10 are input to a pulse width modulation circuit 11, and the output of the pulse width modulation circuit 11 is connected to the switching element 3 via a drive circuit 12.
また、誤差増幅器８の出力は電圧検出回路１３に接続さ
れ、電圧検出回路１３の出力は駆動回路１２に接続され
ている。Further, the output of the error amplifier 8 is connected to a voltage detection circuit 13, and the output of the voltage detection circuit 13 is connected to a drive circuit 12.
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 explained.
スイッチング電源装置の出力電圧は抵抗６，７で分圧さ
れ、基準電圧９との差を誤差増幅器８で増幅する。誤差
増幅器８の出力電圧と発振回路１０の出力電圧をパルス
幅変調回路１１で比較し、駆動回路１２を介してスイッ
チング素子３を駆動する。スイッチング素子３がオン、
オフすることにより電圧変換用トランス２の二次側に交
流電圧が発生し、整流平滑回路４によって直流電圧に変
換されて負荷５に直流電圧を供給する。The output voltage of the switching power supply device is divided by resistors 6 and 7, and the difference from the reference voltage 9 is amplified by an error amplifier 8. The output voltage of the error amplifier 8 and the output voltage of the oscillation circuit 10 are compared by a pulse width modulation circuit 11, and the switching element 3 is driven via a drive circuit 12. Switching element 3 is on,
By turning off, an alternating current voltage is generated on the secondary side of the voltage conversion transformer 2, which is converted into a direct current voltage by the rectifying and smoothing circuit 4, and is supplied to the load 5.
負荷５に供給する出力電流が増加すると、スイッチング
電源装置の出力電圧が低下して抵抗６゜７による分圧電
圧も低下するため基準電圧９との差が増加し、誤差増幅
器８の出力電圧は高くなる。When the output current supplied to the load 5 increases, the output voltage of the switching power supply decreases and the voltage divided by the resistor 6.7 also decreases, so the difference with the reference voltage 9 increases, and the output voltage of the error amplifier 8 becomes It gets expensive.
この高くなった電圧と発振回路１０の出力電圧とがパル
ス幅変調回路１１によって比較されるため、パルス幅変
調回路１１の出力パルスの幅は広くなる。従って、スイ
ッチング素子３のオン、オフの比が増加して整流平滑回
路４の出力電圧は高くなり、負荷５に出力される直流電
圧は一定となる。Since this increased voltage and the output voltage of the oscillation circuit 10 are compared by the pulse width modulation circuit 11, the width of the output pulse of the pulse width modulation circuit 11 becomes wider. Therefore, the on/off ratio of the switching element 3 increases, the output voltage of the rectifying and smoothing circuit 4 increases, and the DC voltage output to the load 5 becomes constant.
逆に、負荷に供給する出力電流が減少すると、スイッチ
ング電源装置の出力電圧が高くなり、抵抗６，７による
分圧電圧も高くなるため基準電圧９との差が増加するが
、極性が逆であるため誤差増幅器８の出力電圧は低くな
る。この低くなった電圧と発振回路１０の出力電圧とパ
ルス幅変調回路１１によって比較されるため、パルス幅
変調回路１１の出力パルス幅は狭くなる。従って、スイ
ッチング素子３のオン、オフの比が減少して整流平滑回
路４の出力電圧は低くなり、負荷５に出力される直流電
圧は一定となる。Conversely, when the output current supplied to the load decreases, the output voltage of the switching power supply increases, and the voltage divided by the resistors 6 and 7 also increases, so the difference from the reference voltage 9 increases, but the polarity is reversed. Therefore, the output voltage of the error amplifier 8 becomes low. Since this lowered voltage is compared with the output voltage of the oscillation circuit 10 by the pulse width modulation circuit 11, the output pulse width of the pulse width modulation circuit 11 becomes narrower. Therefore, the on/off ratio of the switching element 3 decreases, the output voltage of the rectifying and smoothing circuit 4 becomes low, and the DC voltage output to the load 5 becomes constant.
いま、何等かの障害、例えば基準電圧９の電圧が異常に
上昇したとする。このとき、誤差増幅器８の出力電圧は
上昇し、パルス幅変調回路１１の出力パルス幅は広くな
ってスイッチング素子３のオン、オフ比は大きくなり、
整流平滑回路４の出力電圧が高くなってスイッチング電
源装置の出力電圧に過電圧が生じる。この場合、誤差増
幅器８の出力電圧の異常な上昇を過電圧検出回路１３に
よって検出し、駆動回路１２の出力を遮断し、スイッチ
ング電源の動作を停止させる。Now, suppose that some kind of failure occurs, for example, the voltage of the reference voltage 9 rises abnormally. At this time, the output voltage of the error amplifier 8 increases, the output pulse width of the pulse width modulation circuit 11 becomes wider, and the on/off ratio of the switching element 3 becomes larger.
The output voltage of the rectifying and smoothing circuit 4 becomes high, and an overvoltage occurs in the output voltage of the switching power supply device. In this case, the overvoltage detection circuit 13 detects an abnormal increase in the output voltage of the error amplifier 8, cuts off the output of the drive circuit 12, and stops the operation of the switching power supply.
本実施例における過電圧検出ではスイッチング電源装置
の出力電圧が上昇しない内にスイッチング電源装置の動
作を停止させるため、負荷５に対して異常な電圧を印加
することなく過電圧検出を行なうことが可能である。ま
た、誤差増幅器８の出力電圧を検出しているので、スイ
ッチング電源装置の出力電圧の低下も検出可能である。Since the overvoltage detection in this embodiment stops the operation of the switching power supply before the output voltage of the switching power supply increases, it is possible to detect the overvoltage without applying an abnormal voltage to the load 5. . Furthermore, since the output voltage of the error amplifier 8 is detected, a drop in the output voltage of the switching power supply device can also be detected.
以上説明したように本発明は、誤差増幅器の出力電圧を
検出し、ある一定電圧以上になった場合にスイッチング
電源の動作を停止させることにより、スイッチング電源
の出力電圧が過電圧となる障害が生じても負荷には過電
圧が印加されない。As explained above, the present invention detects the output voltage of the error amplifier and stops the operation of the switching power supply when the voltage exceeds a certain level, thereby preventing a problem in which the output voltage of the switching power supply becomes overvoltage. No overvoltage is applied to the load.
スイッチング電源の出力電圧を検出する従来の装置に比
較すると、負荷の許容最大印加電圧に達するまでの時間
が長いため、過電圧を検出してから実際にスイッチング
電源の動作が停止するまでの遅れ時間がある程度長くて
も問題ないという効果がある。Compared to conventional devices that detect the output voltage of switching power supplies, it takes a long time to reach the maximum allowable applied voltage of the load, so there is a delay time between detecting overvoltage and when the switching power supply actually stops operating. The effect is that there is no problem even if it is long to some extent.
また、本発明は誤差増幅器の出力電圧を検出することに
より、スイッチング電源の出力電圧の低下を検出するこ
とにも適用可能である。Furthermore, the present invention is also applicable to detecting a drop in the output voltage of a switching power supply by detecting the output voltage of the error amplifier.
雄側を示す回路図である。FIG. 3 is a circuit diagram showing the male side.
１・・・直流電源、２・・・電圧変換用トランス、３・
・・スイッチング素子、４・・・整流平滑回路、５・・
・負荷、６．７・・・抵抗、８・・・誤差増幅器、９・
・・基準電圧、１０・・・発振回路、１１・・・パルス
幅変調回路、１２・・・駆動回路、１３・・・過電圧検
出回路。1... DC power supply, 2... Voltage conversion transformer, 3...
...Switching element, 4... Rectifier and smoothing circuit, 5...
・Load, 6.7...Resistance, 8...Error amplifier, 9.
... Reference voltage, 10 ... Oscillation circuit, 11 ... Pulse width modulation circuit, 12 ... Drive circuit, 13 ... Overvoltage detection circuit.
Claims (1)
記誤差増幅器の出力電圧と発振回路の出力電圧とを比較
してパルスを得るパルス幅変調回路と、前記パルス幅変
調回路の出力パルスによつて駆動されるスイッチング素
子とを備えるスイッチング電源装置において、前記誤差
増幅器の出力電圧を検出する検出回路を有し、前記検出
回路の検出電圧がある一定電圧以上あるいは一定電圧以
下になつたときに前記スイッチング電源装置の動作を停
止させることを特徴とするスイッチング電源装置。an error amplifier that amplifies the difference between the output voltage and a reference voltage; a pulse width modulation circuit that obtains a pulse by comparing the output voltage of the error amplifier and the output voltage of the oscillation circuit; A switching power supply device comprising a switching element driven by a switching element, further comprising a detection circuit that detects the output voltage of the error amplifier, and when the detection voltage of the detection circuit becomes above a certain voltage or below a certain voltage. A switching power supply device, characterized in that the operation of the switching power supply device is stopped.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21933788A JPH0270265A (en) | 1988-08-31 | 1988-08-31 | Switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21933788A JPH0270265A (en) | 1988-08-31 | 1988-08-31 | Switching power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0270265A true JPH0270265A (en) | 1990-03-09 |
Family
ID=16733876
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21933788A Pending JPH0270265A (en) | 1988-08-31 | 1988-08-31 | Switching power supply |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0270265A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5029269A (en) * | 1990-04-12 | 1991-07-02 | Rockwell International Corporation | Delayed power supply overvoltage shutdown apparatus |
| KR100716955B1 (en) * | 2000-09-29 | 2007-05-10 | 삼성전자주식회사 | Manufacture method of optical connector |
| JP2007318920A (en) * | 2006-05-25 | 2007-12-06 | Rohm Co Ltd | Switching power supply and method and circuit for controlling the same |
-
1988
- 1988-08-31 JP JP21933788A patent/JPH0270265A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5029269A (en) * | 1990-04-12 | 1991-07-02 | Rockwell International Corporation | Delayed power supply overvoltage shutdown apparatus |
| KR100716955B1 (en) * | 2000-09-29 | 2007-05-10 | 삼성전자주식회사 | Manufacture method of optical connector |
| JP2007318920A (en) * | 2006-05-25 | 2007-12-06 | Rohm Co Ltd | Switching power supply and method and circuit for controlling the same |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4453172B2 (en) | Power supply device and power supply system | |
| JPH04355663A (en) | Stabilized power supply | |
| JP2003079050A (en) | Air conditioner | |
| JPH0270265A (en) | Switching power supply | |
| JPH0919156A (en) | Air conditioner | |
| JPH08289468A (en) | Dc power supply for parallel operation | |
| JPH0785648B2 (en) | Switching regulator power supply circuit | |
| JPS61244271A (en) | Switching regulator | |
| JPH02211055A (en) | Abnormal operation detecting circuit of dc/dc converter | |
| JPS6338942B2 (en) | ||
| JPH0241274B2 (en) | ||
| JPS63287364A (en) | Auxiliary power circuit for switching regulator | |
| JPH055835Y2 (en) | ||
| JPH05316741A (en) | Bidirectional power converter | |
| JPH02280670A (en) | Power source equipment | |
| JPH0646560A (en) | Voltage detecting circuit for switching power supply | |
| JPS62152372A (en) | Power source device | |
| KR0172862B1 (en) | Circuit for controlling the pulse width of switching source | |
| JPH089780Y2 (en) | Power supply circuit | |
| KR830001379B1 (en) | Multiphase Hybrid Rectifier Bridge Protected from Rectifier Obstruction | |
| JPH0343836Y2 (en) | ||
| JPH0686454A (en) | Power device | |
| JPH0127427Y2 (en) | ||
| JPH08256475A (en) | Switching power unit | |
| JPH0518288U (en) | Overcurrent protection circuit for switching regulator |