JPH04372575A - Switching regulator - Google Patents
Switching regulatorInfo
- Publication number
- JPH04372575A JPH04372575A JP15070891A JP15070891A JPH04372575A JP H04372575 A JPH04372575 A JP H04372575A JP 15070891 A JP15070891 A JP 15070891A JP 15070891 A JP15070891 A JP 15070891A JP H04372575 A JPH04372575 A JP H04372575A
- Authority
- JP
- Japan
- Prior art keywords
- resistor
- series
- control
- starting resistor
- power supply
- 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
- 238000004804 winding Methods 0.000 claims abstract description 38
- 238000002955 isolation Methods 0.000 claims description 16
- 230000005669 field effect Effects 0.000 claims description 5
- 239000003990 capacitor Substances 0.000 abstract description 10
- 238000006243 chemical reaction Methods 0.000 abstract description 6
- 238000010586 diagram Methods 0.000 description 6
- 238000009499 grossing Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 101150015217 FET4 gene Proteins 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
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Abstract
Description
【0001】0001
【産業上の利用分野】この発明は、交流電力を一旦直流
電力に変換し、これをPWM変調制御した後、定電圧の
直流電力に変換して出力する、フォワ−ド型またはフラ
イバック型などの他励式スイッチングレギュレ−タ、こ
とにPWM変調を制御する制御用ICの起動抵抗の電力
損失を低減する回路を備えたスイッチングレギュレ−タ
に関する。[Industrial Application Field] This invention is applicable to forward type or flyback type power supplies, which first convert AC power to DC power, perform PWM modulation control, and then convert it to constant voltage DC power and output it. The present invention relates to a separately excited switching regulator, and particularly to a switching regulator equipped with a circuit for reducing power loss in a starting resistor of a control IC that controls PWM modulation.
【0002】0002
【従来の技術】図3は従来のフォワ−ド型の他励式スイ
ッチングレギュレ−タを示す接続図であり、交流電圧V
acを直流変換するダイオ−ドブリッジ1の出力側には
、一端が接地された平滑コンデンサ2と、絶縁トランス
3の1次巻線3Pと、1次巻線にドレ−ンが接続され,
ソ−スが接地された絶縁ゲ−ト電界効果トランジスタ(
MOSFET)4とで閉回路が形成され、制御用IC5
が1次巻線電流をPWM変調制御する信号5SをMOS
FET4のゲ−トGに向けて出力することにより、MO
SFETは所定の時比率でオンオフ動作し、閉回路には
方形波パルス電流が流れる。また、1次巻線と同じ極性
を有する2次巻線に巻線比に基づく大きさで誘起したパ
ルス電流は、ダイオ−ドDs,Dp,リアクトルL8,
コンデンサC8 からなるフォワ−ド回路8により平均
値化された直流定電圧に変換され、外部負荷に供給され
る。[Prior Art] FIG. 3 is a connection diagram showing a conventional forward-type separately excited switching regulator.
On the output side of the diode bridge 1 that converts AC to DC, a smoothing capacitor 2 whose one end is grounded, a primary winding 3P of an isolation transformer 3, and a drain connected to the primary winding.
An insulated gate field effect transistor with a grounded source (
A closed circuit is formed with MOSFET) 4, and control IC 5
The signal 5S that controls the primary winding current by PWM modulation is MOS
By outputting to gate G of FET4, MO
The SFET is turned on and off at a predetermined time ratio, and a square wave pulse current flows through the closed circuit. In addition, the pulse current induced in the secondary winding having the same polarity as the primary winding with a magnitude based on the turns ratio is generated by the diodes Ds, Dp, the reactor L8,
A forward circuit 8 comprising a capacitor C8 converts the voltage into an averaged constant DC voltage and supplies it to an external load.
【0003】一方、制御用IC5の電源電圧Vccの入
力端子5Aには、絶縁トランス3の補助巻線3Aの電圧
をダイオ−ド6D,コンデンサ6Cで直流に変換する電
源回路6と、ダイオ−ドブリッジ1の出力側に一端が接
続された起動抵抗10とが接続され、制御用IC5の起
動時には起動抵抗10を介して電源電圧Vccが供給さ
れ、起動後は起動抵抗10および電源回路6の双方から
電源電圧Vccが供給される。また、フォワ−ド回路8
に流れる電流は検出抵抗R9 の電圧降下として電流検
出器9により検出され、その検出値が制御用ICで基準
値と比較されて誤差増幅され、基準値との差に対応した
時比率の制御信号5SがMOSFET4のゲ−トに供給
される。On the other hand, the input terminal 5A of the power supply voltage Vcc of the control IC 5 is connected to a power supply circuit 6 that converts the voltage of the auxiliary winding 3A of the isolation transformer 3 into direct current using a diode 6D and a capacitor 6C, and a diode bridge. A starting resistor 10, one end of which is connected to the output side of the control IC 5, is connected, and when the control IC 5 is started, a power supply voltage Vcc is supplied through the starting resistor 10, and after starting, a power supply voltage Vcc is supplied from both the starting resistor 10 and the power supply circuit 6. Power supply voltage Vcc is supplied. In addition, the forward circuit 8
The current flowing through is detected by the current detector 9 as a voltage drop across the detection resistor R9, and the detected value is compared with a reference value in the control IC, the error is amplified, and a control signal with a duty ratio corresponding to the difference from the reference value is generated. 5S is supplied to the gate of MOSFET4.
【0004】0004
【発明が解決しようとする課題】上述の従来技術におい
て、起動抵抗10は制御用IC5が起動し、補助巻線3
Aに電圧が定常的に発生した時点(スイッチングレギュ
レ−タが定常運転を開始した時点)で不必要になる。と
ころが、従来の装置ではスイッチングレギュレ−タが定
常運転をしている状態でも、起動抵抗10が制御用IC
の電源電圧の入力端子5Aに接続されて制御用ICに電
源電流の一部を供給し続ける。したがって、起動抵抗1
0で定常的に電力損失が発生し、その値が内部抵抗の低
い電源回路6で発生する電力損失を大きく上回るために
、例えば定挌出力100W程度のスイッチングレギュレ
−タで電力変換効率が1ないし2%程度低下するという
問題が発生する。ことに、スイッチングレギュレ−タは
、スイッチング周波数を例えば20KHz 以上に上げ
ることにより、絶縁トランスなどの磁気部品や平滑コン
デンサ等を小型化でき、かつ出力電圧のレギュレ−ショ
ンをMOSFETのスイッチング動作で行うことで電力
損失を小さくできることが特徴の電源装置であり、起動
抵抗での無駄な電力消費と、これによる電力変換効率の
低下の阻止が重要な課題となる。[Problems to be Solved by the Invention] In the above-mentioned prior art, the starting resistor 10 is activated by the control IC 5 and the auxiliary winding 3
It becomes unnecessary when a voltage is steadily generated at A (when the switching regulator starts steady operation). However, in conventional devices, even when the switching regulator is in steady operation, the starting resistor 10 is connected to the control IC.
It is connected to the input terminal 5A of the power supply voltage and continues to supply a part of the power supply current to the control IC. Therefore, starting resistance 1
Since power loss occurs constantly at 0, and the value greatly exceeds the power loss generated in the power supply circuit 6 with low internal resistance, for example, a switching regulator with a constant output of about 100 W has a power conversion efficiency of 1 A problem arises in which the power decreases by about 2%. In particular, switching regulators can reduce the size of magnetic components such as isolation transformers, smoothing capacitors, etc. by increasing the switching frequency to, for example, 20 KHz or higher, and can regulate the output voltage by the switching operation of MOSFETs. This power supply device is characterized by its ability to reduce power loss, and an important issue is to prevent wasteful power consumption in the starting resistor and the resulting decrease in power conversion efficiency.
【0005】この発明は、制御用ICの起動後は起動抵
抗を制御用ICから切り離すことにより、起動抵抗で生
ずる無駄な電力損失の発生を阻止することにある。[0005] This invention aims to prevent wasteful power loss caused by the starting resistor by separating the starting resistor from the controlling IC after the controlling IC is started.
【0006】[0006]
【課題を解決するための手段】上記課題を解決するため
に、この発明によれば、ダイオ−ドブリッジと絶縁トラ
ンスの1次巻線との間に直列接続された電界効果トラン
ジスタをオン,オフ制御する制御用ICが、その電源電
圧の入力端子と前記ダイオ−ドブリッジの出力側との間
に接続された起動抵抗、および前記絶縁トランスの補助
巻線電圧を整流して前記入力端子に供給する電源回路を
備えたものにおいて、前記制御用ICの起動後前記補助
巻線電圧の発生を検知して前記起動抵抗を前記電源電圧
の入力端子から切り離す遮断回路を備えてなるものとす
る。[Means for Solving the Problems] In order to solve the above problems, according to the present invention, a field effect transistor connected in series between a diode bridge and a primary winding of an isolation transformer is turned on and off. A control IC that rectifies the starting resistor connected between the input terminal of the power supply voltage and the output side of the diode bridge, and the auxiliary winding voltage of the isolation transformer and supplies the rectified power to the input terminal. The device including a circuit includes a cutoff circuit that detects generation of the auxiliary winding voltage after the control IC is started and disconnects the starting resistor from the input terminal of the power supply voltage.
【0007】また遮断回路が、起動抵抗と制御用ICの
電源電圧の入力端子側との間にコレクタおよびエミッタ
が直列接続されたトランジスタと、ダイオ−ドブリッジ
の直流出力側に並列接続された直列抵抗およびトライア
ックの直列回路とからなり、前記トライアックのゲ−ト
が絶縁トランスの補助巻線に接続され、前記トランジス
タのベ−スが前記直列回路の中間接続点に接続されてな
るものとする。The cutoff circuit also includes a transistor whose collector and emitter are connected in series between the starting resistor and the power supply voltage input terminal of the control IC, and a series resistor which is connected in parallel to the DC output side of the diode bridge. and a series circuit of a triac, the gate of the triac being connected to an auxiliary winding of an isolation transformer, and the base of the transistor being connected to an intermediate connection point of the series circuit.
【0008】さらに直列抵抗の抵抗値を起動抵抗のそれ
に比べ10倍程度以上高く形成してなるものとする。Furthermore, the resistance value of the series resistor is made to be about 10 times or more higher than that of the starting resistor.
【0009】[0009]
【作用】この発明の構成において、制御用ICの起動後
、補助巻線電圧の発生を検知して起動抵抗を制御用IC
の電源電圧の入力端子から切り離す遮断回路を設けるよ
う構成したことにより、スイッチングレギュレ−タの定
常運転中に起動抵抗で発生する電力損失が排除され、し
たがってスイッチングレギュレ−タの電力変換効率を従
来のそれに比べて1ないし2%程度改善する機能が得ら
れる。[Operation] In the configuration of the present invention, after the control IC is started, the generation of the auxiliary winding voltage is detected and the starting resistance is changed to the control IC.
By providing a cutoff circuit that disconnects the power supply voltage from the input terminal of the switching regulator, the power loss that occurs in the starting resistor during steady operation of the switching regulator is eliminated. Compared to this, a function improved by about 1 to 2% can be obtained.
【0010】また遮断回路を、起動抵抗と制御用ICの
電源電圧の入力端子側との間にコレクタおよびエミッタ
が直列接続されたトランジスタと、ダイオ−ドブリッジ
の直流出力側に並列接続された直列抵抗およびトライア
ックの直列回路とからなり、トライアックのゲ−トを絶
縁トランスの補助巻線に接続し、トランジスタのベ−ス
を直列回路の中間接続点に接続するよう構成すれば、補
助巻線電圧をトライアックが感知して導通状態となり、
トランジスタのベ−ス電流を大地側に側路するため、ト
ランジスタがオフして起動抵抗に流れる電流を遮断する
機能が得られるとともに、直列抵抗と二つの小容量の半
導体素子とからなる小型かつ簡素な構成の遮断回路を得
ることができる。[0010] The cutoff circuit also includes a transistor whose collector and emitter are connected in series between the starting resistor and the power supply voltage input terminal side of the control IC, and a series resistor connected in parallel to the DC output side of the diode bridge. The gate of the triac is connected to the auxiliary winding of the isolation transformer, and the base of the transistor is connected to the intermediate connection point of the series circuit. The triac senses and becomes conductive,
Since the base current of the transistor is bypassed to the ground side, the transistor is turned off and the current flowing to the starting resistor is cut off. It is possible to obtain a cut-off circuit with a suitable configuration.
【0011】さらに、直列抵抗の抵抗値を起動抵抗のそ
れに比べ10倍程度以上高く形成すれば、スイッチング
レギュレ−タの定常運転中トライアックを介して直列抵
抗に流れる電流が抑制されるので、遮断回路の電力損失
を著しく小さくできる機能が得られる。Furthermore, if the resistance value of the series resistor is made to be about 10 times or more higher than that of the starting resistor, the current flowing to the series resistor via the triac during steady operation of the switching regulator is suppressed, so that the breaking circuit This provides the ability to significantly reduce power loss.
【0012】0012
【実施例】以下、この発明を実施例に基づいて説明する
。図1はこの発明の実施例になるフォワ−ド形の他励式
スイッチングレギュレ−タを示す接続図であり、従来技
術と同じ構成部分には同一参照符号を付すことにより、
重複した説明を省略する。図において、遮断回路11は
、一端が接地されたダイオ−ドブリッジ1の直流出力側
に並列接続された直列抵抗13とトライアック14の直
列回路と、起動抵抗10と制御用IC電源電圧の入力端
子5Aとの間にコレクタCおよびエミッタEが接続され
たトランジスタ(図の場合npnトランジスタ)12と
で構成され、トランジスタ12のベ−スGは直列抵抗と
トライアックの中間接続点mに接続され、トライアック
14のゲ−トGは補助巻線3Aの非接地端子に接続され
る。また、直列抵抗13の抵抗値は起動抵抗10のそれ
に比べて10倍以上高い抵抗値に設定される。EXAMPLES The present invention will be explained below based on examples. FIG. 1 is a connection diagram showing a forward type separately excited switching regulator according to an embodiment of the present invention, and the same reference numerals are given to the same components as in the prior art.
Omit duplicate explanations. In the figure, the cutoff circuit 11 includes a series circuit of a series resistor 13 and a triac 14 connected in parallel to the DC output side of the diode bridge 1 whose one end is grounded, a starting resistor 10, and an input terminal 5A for the control IC power supply voltage. The base G of the transistor 12 is connected to the intermediate connection point m between the series resistor and the triac, and the collector C and emitter E are connected between the transistor 12 (npn transistor in the figure). The gate G of is connected to the non-ground terminal of the auxiliary winding 3A. Further, the resistance value of the series resistor 13 is set to a resistance value ten times or more higher than that of the starting resistor 10.
【0013】このように構成された遮断回路11を備え
たスイッチングレギュレ−タにおいて、制御用IC5が
起動しない状態では、MOSFET4が動作せず、補助
巻線電圧も零なのでトライアック14はオフ状態にある
。また、電源回路6のコンデンサ6Cも未充電状態にあ
り、トランジスタ12のエミッタも等価的に接地状態に
ある。したがって、トランジスタのベ−ス,エミッタ間
には直列抵抗13を介して順電圧が印加され、コレクタ
,ベ−ス間には抵抗10および13の電位降下の差によ
る順電圧が印加されるので、トランジスタ12は導通状
態となり、起動抵抗10で所定値に制御されたエミッタ
電流によりコンデンサ6Cが充電され、制御用ICの電
源電圧の入力端子5Aに電源電圧Vccが印加され、制
御用IC5が起動する。In the switching regulator equipped with the cutoff circuit 11 configured as described above, when the control IC 5 is not activated, the MOSFET 4 does not operate and the auxiliary winding voltage is also zero, so the triac 14 is in the off state. . Further, the capacitor 6C of the power supply circuit 6 is also in an uncharged state, and the emitter of the transistor 12 is also equivalently in a grounded state. Therefore, a forward voltage is applied between the base and emitter of the transistor via the series resistor 13, and a forward voltage due to the difference in potential drop between the resistors 10 and 13 is applied between the collector and the base. The transistor 12 becomes conductive, the capacitor 6C is charged by the emitter current controlled to a predetermined value by the starting resistor 10, the power supply voltage Vcc is applied to the power supply voltage input terminal 5A of the control IC, and the control IC 5 is started. .
【0014】制御用ICが起動してMOSFET4を所
定の時比率でオンオフ制御すると、1次巻線にパルス電
流が流れ、補助巻線3Aに補助巻線電圧が発生し、ダイ
オ−ド6Dを介してコンデンサ6Cを充電するとともに
、補助巻線電圧がトライアック14のゲ−トに印加され
、トライアックは導通状態となり、トランジスタ12の
ベ−スはほぼ大地電位に低下する。その結果、トランジ
スタのベ−ス,エミッタ間には逆バイアス電圧が加わり
、トランジスタ12はオフ状態に変化し、起動抵抗10
を流れる電流は遮断される。したがって、その後は電源
回路6から制御用ICに電源電圧Vccを供給して定常
運転を行うことになり、起動抵抗10の電力損失は零に
なる。また、電源回路6は内部抵抗が低く、その電力損
失は起動抵抗のそれに比べて大幅に少ない。さらに、ト
ライアックの導通により直列抵抗13には常時ダイオ−
ドブリッジの出力直流電圧が印加されるが、直列抵抗の
抵抗値を起動抵抗10のそれの数十倍とすることにより
、小さく抑えることができる。その結果、スイッチング
レギュレ−タの電力変換効率を従来のそれに比べ例えば
1ないし2%程度改善できる利点が得られる。When the control IC starts up and controls the MOSFET 4 to turn on and off at a predetermined time ratio, a pulse current flows through the primary winding, and an auxiliary winding voltage is generated in the auxiliary winding 3A, which is applied via the diode 6D. At the same time, the auxiliary winding voltage is applied to the gate of the triac 14, the triac becomes conductive, and the base of the transistor 12 drops to approximately ground potential. As a result, a reverse bias voltage is applied between the base and emitter of the transistor, the transistor 12 turns off, and the starting resistor 10
The current flowing through is cut off. Therefore, after that, the power supply voltage Vcc is supplied from the power supply circuit 6 to the control IC to perform steady operation, and the power loss of the starting resistor 10 becomes zero. Further, the power supply circuit 6 has a low internal resistance, and its power loss is significantly lower than that of the starting resistor. Furthermore, due to the conduction of the triac, the series resistor 13 always has a diode.
Although the output DC voltage of the bridge is applied, it can be suppressed to a small value by making the resistance value of the series resistor several tens of times that of the starting resistor 10. As a result, there is an advantage that the power conversion efficiency of the switching regulator can be improved, for example, by about 1 to 2% compared to the conventional one.
【0015】図2はこの発明の異なる実施例になるフラ
イバック形の他励式スイッチングレギュレ−タを示す接
続図であり、前述の実施例と異なる点は、スイッチング
レギュレ−タの絶縁トランス30が、その1次巻線30
Pと2次巻線30Sの極性が互いに逆向きに形成され、
MOSFET4がオフしている時に絶縁トランス30に
蓄えられたエネルギ−が放出され、ダイオ−ド31を介
して1次巻線電流が流れるとともに、2次巻線電流が整
流回路31で整流され、平均化された定電圧直流電力を
外部負荷に供給する、いわゆるフライバック形に形成さ
れていることであり、この場合も、トランジスタ12,
直列抵抗13,およびトライアック14で構成される遮
断回路11を設けることにより、前述の実施例と同様に
、補助巻線電圧を検知して起動抵抗に流れる電流を遮断
し、定常運転時に起動抵抗で生ずる電力損失を排除する
ことができる。FIG. 2 is a connection diagram showing a flyback type separately excited switching regulator according to a different embodiment of the present invention.The difference from the above embodiment is that the isolation transformer 30 of the switching regulator is Its primary winding 30
P and the polarity of the secondary winding 30S are formed in opposite directions to each other,
When the MOSFET 4 is off, the energy stored in the isolation transformer 30 is released, and the primary winding current flows through the diode 31, and the secondary winding current is rectified by the rectifier circuit 31, and the average It is formed in a so-called flyback type that supplies constant voltage DC power to an external load.
By providing a cutoff circuit 11 consisting of a series resistor 13 and a triac 14, the auxiliary winding voltage is detected and the current flowing to the starting resistor is cut off, similarly to the previous embodiment, and the starting resistor is used during steady operation. The resulting power loss can be eliminated.
【0016】[0016]
【発明の効果】この発明は前述のように、制御用ICの
起動後、補助巻線電圧の発生を検知して起動抵抗を制御
用ICの電源電圧の入力端子から切り離す遮断回路を設
けるよう構成した。その結果、従来の技術で問題となっ
たスイッチングレギュレ−タの定常運転中に起動抵抗で
発生する電力損失が排除され、したがって電力変換効率
を従来のそれに比べて1ないし2%程度改善した電力変
換効率の高いスイッチングレギュレ−タを提供すること
ができる。[Effects of the Invention] As described above, the present invention is configured to provide a cutoff circuit that detects the generation of auxiliary winding voltage after the control IC is started and disconnects the starting resistor from the power supply voltage input terminal of the control IC. did. As a result, the power loss that occurs in the starting resistance during steady operation of switching regulators, which was a problem with conventional technology, has been eliminated, and the power conversion efficiency has been improved by about 1 to 2% compared to the conventional technology. A highly efficient switching regulator can be provided.
【0017】また遮断回路を、起動抵抗と制御用ICの
電源電圧の入力端子側との間にコレクタおよびエミッタ
が直列接続されたトランジスタと、ダイオ−ドブリッジ
の直流出力側に並列接続された直列抵抗とトライアック
の直列回路とで構成し、トライアックのゲ−トを絶縁ト
ランスの補助巻線に接続し、トランジスタのベ−スを直
列回路の中間接続点に接続するようにすれば、補助巻線
電圧をトライアックが感知して導通状態となり、トラン
ジスタのベ−ス電流を大地側に側路するため、トランジ
スタがオフして起動抵抗に流れる電流を遮断する機能を
、直列抵抗と,二つの小容量の半導体素子とからなる小
型かつ簡素な構成の遮断回路を用いて得ることができる
ので、電力変換効率の高いスイッチングレギュレ−タを
経済的に有利に提供することができる。[0017] The cutoff circuit is also formed by a transistor whose collector and emitter are connected in series between the starting resistor and the power supply voltage input terminal side of the control IC, and a series resistor which is connected in parallel to the DC output side of the diode bridge. If the gate of the triac is connected to the auxiliary winding of the isolation transformer, and the base of the transistor is connected to the intermediate connection point of the series circuit, the auxiliary winding voltage can be reduced. The triac senses this and becomes conductive, bypassing the base current of the transistor to the ground.The function of turning off the transistor and cutting off the current flowing to the starting resistor is achieved by using a series resistor and two small capacitors. Since the switching regulator can be obtained using a small and simple-structured cut-off circuit made of semiconductor elements, it is possible to economically advantageously provide a switching regulator with high power conversion efficiency.
【0018】さらに、直列抵抗の抵抗値を起動抵抗のそ
れに比べ10倍程度以上高く形成すれば、スイッチング
レギュレ−タの定常運転中トライアックを介して流れる
電流を抑制できるので、電力損失の少ない遮断回路を備
えたスイッチングレギュレ−タを提供することができる
。Furthermore, if the resistance value of the series resistor is made to be about 10 times higher than that of the starting resistor, the current flowing through the triac during steady operation of the switching regulator can be suppressed, so that a cutoff circuit with low power loss can be realized. A switching regulator can be provided.
【図1】この発明の実施例になるフォワ−ド形の他励式
スイッチングレギュレ−タを示す接続図[Fig. 1] A connection diagram showing a forward type separately excited switching regulator according to an embodiment of the present invention.
【図2】この発
明の異なる実施例になるフライバック形の他励式スイッ
チングレギュレ−タを示す接続図[Fig. 2] A connection diagram showing a flyback type separately excited switching regulator according to a different embodiment of the present invention.
【図3】従来のフォワ
−ド型の他励式スイッチングレギュレ−タを示す接続図[Figure 3] Connection diagram showing a conventional forward type separately excited switching regulator
1 ダイオ−ドブリッジ
2 平滑コンデンサ
3 絶縁トランス
3P 1次巻線
3S 2次巻線
4 絶縁ゲ−ト電界効果トランジスタ(MOSF
ET)
5 制御用IC
6 電源回路
6c コンデンサ
8 フォワ−ド回路
9 電流検出器
10 起動抵抗
11 遮断回路
12 トランジスタ
13 直列抵抗
14 トライアック
30 絶縁トランス
32 整流回路1 Diode bridge 2 Smoothing capacitor 3 Isolation transformer 3P Primary winding 3S Secondary winding 4 Insulated gate field effect transistor (MOSF
ET) 5 Control IC 6 Power supply circuit 6c Capacitor 8 Forward circuit 9 Current detector 10 Starting resistor 11 Cutoff circuit 12 Transistor 13 Series resistor 14 Triac 30 Isolation transformer 32 Rectifier circuit
Claims (3)
巻線との間に直列接続された電界効果トランジスタをオ
ン,オフ制御する制御用ICが、その電源電圧の入力端
子と前記ダイオ−ドブリッジの出力側との間に接続され
た起動抵抗、および前記絶縁トランスの補助巻線電圧を
整流して前記入力端子に供給する電源回路とを備えたも
のにおいて、前記制御用ICの起動後前記補助巻線電圧
の発生を検知して前記起動抵抗を前記電源電圧の入力端
子から切り離す遮断回路を備えてなることを特徴とする
スイッチングレギュレ−タ。1. A control IC for controlling on/off a field effect transistor connected in series between a diode bridge and a primary winding of an isolation transformer, the control IC has a power supply voltage input terminal and a field effect transistor connected in series between the diode bridge and the primary winding of the isolation transformer. A power supply circuit comprising a starting resistor connected between an output side and a power supply circuit that rectifies the auxiliary winding voltage of the isolation transformer and supplies it to the input terminal, wherein the auxiliary winding voltage is rectified and supplied to the input terminal after the control IC is started. A switching regulator comprising a cutoff circuit that detects generation of line voltage and disconnects the starting resistor from the input terminal of the power supply voltage.
電圧の入力端子側との間にコレクタおよびエミッタが直
列接続されたトランジスタと、ダイオ−ドブリッジの直
流出力側に並列接続された直列抵抗およびトライアック
の直列回路とからなり、前記トライアックのゲ−トが絶
縁トランスの補助巻線に接続され、前記トランジスタの
ベ−スが前記直列回路の中間接続点に接続されてなるこ
とを特徴とする請求項1記載のスイッチングレギュレ−
タ。Claim 2: The cutoff circuit includes a transistor whose collector and emitter are connected in series between the starting resistor and the power supply voltage input terminal side of the control IC, and a transistor whose collector and emitter are connected in series to the DC output side of the diode bridge. It comprises a series circuit of a resistor and a triac, the gate of the triac being connected to an auxiliary winding of an isolation transformer, and the base of the transistor being connected to an intermediate connection point of the series circuit. The switching regulator according to claim 1, wherein
Ta.
10倍程度以上高く形成してなることを特徴とする請求
項2記載のスイッチングレギュレ−タ。3. The switching regulator according to claim 2, wherein the resistance value of the series resistor is made to be about 10 times or more higher than that of the starting resistor.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15070891A JPH04372575A (en) | 1991-06-24 | 1991-06-24 | Switching regulator |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15070891A JPH04372575A (en) | 1991-06-24 | 1991-06-24 | Switching regulator |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH04372575A true JPH04372575A (en) | 1992-12-25 |
Family
ID=15502679
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP15070891A Pending JPH04372575A (en) | 1991-06-24 | 1991-06-24 | Switching regulator |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH04372575A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018186084A1 (en) * | 2017-04-07 | 2018-10-11 | 富士通株式会社 | Power supply circuit |
-
1991
- 1991-06-24 JP JP15070891A patent/JPH04372575A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018186084A1 (en) * | 2017-04-07 | 2018-10-11 | 富士通株式会社 | Power supply circuit |
JP2018182846A (en) * | 2017-04-07 | 2018-11-15 | 富士通株式会社 | Power source circuit |
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