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JPS59103567A - Overcurrent protecting circuit for transistor - Google Patents

Overcurrent protecting circuit for transistor

Info

Publication number
JPS59103567A
JPS59103567A JP57210885A JP21088582A JPS59103567A JP S59103567 A JPS59103567 A JP S59103567A JP 57210885 A JP57210885 A JP 57210885A JP 21088582 A JP21088582 A JP 21088582A JP S59103567 A JPS59103567 A JP S59103567A
Authority
JP
Japan
Prior art keywords
transistor
circuit
emitter
base
main transistor
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.)
Granted
Application number
JP57210885A
Other languages
Japanese (ja)
Other versions
JPH0243429B2 (en
Inventor
Kazuo Kuroki
一男 黒木
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fuji Electric Co Ltd
Original Assignee
Fuji Electric Co Ltd
Fuji Electric Manufacturing Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Fuji Electric Co Ltd, Fuji Electric Manufacturing Co Ltd filed Critical Fuji Electric Co Ltd
Priority to JP57210885A priority Critical patent/JPS59103567A/en
Priority to DE19833343201 priority patent/DE3343201A1/en
Publication of JPS59103567A publication Critical patent/JPS59103567A/en
Publication of JPH0243429B2 publication Critical patent/JPH0243429B2/ja
Granted legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03KPULSE TECHNIQUE
    • H03K17/00Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/08Modifications for protecting switching circuit against overcurrent or overvoltage
    • H03K17/081Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit
    • H03K17/0812Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit by measures taken in the control circuit
    • H03K17/08126Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit by measures taken in the control circuit in bipolar transitor switches
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02MAPPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00Conversion of DC power input into DC power output
    • H02M3/02Conversion of DC power input into DC power output without intermediate conversion into AC
    • H02M3/04Conversion of DC power input into DC power output without intermediate conversion into AC by static converters
    • H02M3/10Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)
  • Electronic Switches (AREA)
  • Protection Of Static Devices (AREA)
  • Power Conversion In General (AREA)
  • Inverter Devices (AREA)

Abstract

PURPOSE:To effectively protect a main transistor against an overcurrent with an inexpensive configuration by interrupting the base current of the transistor instantaneously when the voltage between the collector and the emitter of the transistor increases to the specified value or higher. CONSTITUTION:When an ON signal is produced at the output terminal A of an ON/OFF signal circuit 1, a main transistor 4 becomes ON. When the collector current of the transistor 4 becomes the specified value or higher, the voltage between the collector and the emitter of the transistor 4 becomes large, and a control transistor 5 becomes switch ON. As a result, the current flowed from the base to the emitter of the transistor 4 is commutated to the transistor 5, and the transistor 4 becomes OFF.

Description

【発明の詳細な説明】 本発明は、電力変換装置等でスイッチング素子として使
用されるトランジスタの過電流保護回路に関するもので
ある。
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an overcurrent protection circuit for transistors used as switching elements in power converters and the like.

かかるトランジスタが過電流となる要因は大別して2種
類あシ、その一つは過負荷によるものでこの場合は電流
の時間的変化(di/dt )は小さく保護は比較的容
易である。他の一つはブリッジ形インバータ回路のごと
く直流電源に2つのトランジスタを直列接続した回路構
成で、一つのトランジスタに短絡故障が生じたときの他
のトう/ジスタにおける電源短絡による過電流で、この
場合は電流の時間的変化は非常に大きく保護は困難であ
る。
The causes of overcurrent in such a transistor can be roughly divided into two types. One of them is overload, and in this case, the temporal change in current (di/dt) is small and protection is relatively easy. The other type is a circuit configuration in which two transistors are connected in series to a DC power supply like a bridge type inverter circuit, and when a short-circuit failure occurs in one transistor, an overcurrent due to a short-circuit in the power supply in the other transistor/transistor occurs. In this case, the temporal change in current is very large and protection is difficult.

一方、トランジスタは従来から変換装置に使用されてい
るサイリスタに比べると過電流耐量が小さくヒユーズに
よる保護は期待できない。
On the other hand, transistors have a smaller overcurrent withstand capacity than thyristors conventionally used in conversion devices, and cannot be expected to be protected by fuses.

ます、従来の過電流保護回路について説明し、よって本
発明の目的を明らかにする。
First, a conventional overcurrent protection circuit will be described, thereby clarifying the object of the present invention.

第1図に示すように、オン・オフ信号回路lのオフ信号
出力端子に制限抵抗2を介して主トランジスタ4のベー
ス・エミッタ間が接続され、主トランジスタ4のベース
・エミッタ間に流される順バイアス電流■1によって主
トランジスタ4がオンされ、f1=0の状態でオフ信号
出力端子を介して供給される逆バイアス電流工2によっ
て主トランジスタ4はオフされる。
As shown in FIG. 1, the base-emitter of the main transistor 4 is connected to the off-signal output terminal of the on-off signal circuit l via the limiting resistor 2, and the order in which the current flows between the base and emitter of the main transistor 4 is The main transistor 4 is turned on by the bias current 1, and the main transistor 4 is turned off by the reverse bias current 2 supplied via the off signal output terminal in the state of f1=0.

主トランジスタ4のベース・エミッタ間に並列接続され
ているダイオード3は保護ダイオードである。オン・オ
フ信号回路1としては、例えば特開昭57−15121
号公報に示されているベース駆動回路を使用することが
できる。
A diode 3 connected in parallel between the base and emitter of the main transistor 4 is a protection diode. As the on/off signal circuit 1, for example, Japanese Patent Application Laid-Open No. 57-15121
The base drive circuit shown in the publication can be used.

従来例の一つはかがる回路において、主トランジスタ4
のコレクタに絶縁形電流検出器19を直列接続し、該検
出器19に接続した過電流検出回路:2゜で過電流を検
出してオン・オフ信号回路lを介して主トランジスタ4
をオフさせるものである。
One of the conventional examples is a circuit in which the main transistor 4
An insulated current detector 19 is connected in series to the collector of the overcurrent detector 19, and an overcurrent detection circuit connected to the detector 19 detects an overcurrent at 2° and outputs the main transistor 4 via an on/off signal circuit l.
It turns off.

しかし、この場合は電流検出器19として直流変流器を
使用すると非常に高価なものとなシ、丑だ交流変流器を
使用するには回路構成が複雑にな9信頼性及びコストの
面で問題を生じる。
However, in this case, if a DC current transformer is used as the current detector 19, it will be very expensive, and if an AC current transformer is used, the circuit configuration will be complicated9. This causes problems.

また、ノイズによる誤動作を避けるために過電流検出回
路20の中にはフィルタ回路が必要となシ、その結果高
速性が失なわれ、急峻な電流上昇に対する過電流保護は
難かしいものとなる。
Furthermore, a filter circuit is required in the overcurrent detection circuit 20 to avoid malfunctions due to noise, and as a result, high speed performance is lost and overcurrent protection against steep current increases becomes difficult.

従来例の他の方法は、第2図に示すように主トランジス
タ4のエミッタに抵抗21を直列接続してエミッタ電流
に比例した電圧を取り出し、過電流検出回路22で判断
して過電流を検出し、オン・オフ信号回路lを介して主
トランジスタ4をオフさせるものである。
Another conventional method is to connect a resistor 21 in series to the emitter of the main transistor 4 to extract a voltage proportional to the emitter current, as shown in FIG. Then, the main transistor 4 is turned off via the on/off signal circuit l.

しかし、この場合は主回路に抵抗21が挿入させるので
損失が大きく、またスイッチング動作で使用するので無
誘導形の抵抗が必要となる。
However, in this case, since the resistor 21 is inserted into the main circuit, the loss is large, and since it is used for switching operation, a non-inductive type resistor is required.

、さらに、制御回路との絶縁が取れないなどの欠点があ
シ、特に大容量の装置への適用は難しい。
Moreover, it has drawbacks such as the inability to insulate it from the control circuit, making it particularly difficult to apply to large-capacity devices.

本発明の目的は前記従来例の欠点を1ケr消し、主回路
の損失を増加させることなく、電流の時間的変化(di
/dt )の急峻な過電流に対するトランジスタの保護
を簡単かつ安価な回路構成にょシ確実に行なわせること
ができる回路を提供することにある。
The purpose of the present invention is to eliminate one degree of the drawbacks of the conventional example, and to reduce the temporal change in current (di
An object of the present invention is to provide a circuit that can reliably protect a transistor against a steep overcurrent of /dt) with a simple and inexpensive circuit configuration.

この目的は本発明によれば、スイッチング素子たる主ト
ランジスタのベース・エミッタ間とその主トランジスタ
を制御するオン・オフ信号回路との間に介在し、主トラ
ンジスタのベース順バイアス電流の遮断を可能にすべく
、主トランジスタのベース・エミッタ間を直接的に橋絡
するがもしくは主トランジスタにベース順バイアス電流
を導く補助トランジスタのベース・エミッタ間を橋絡す
る制御トランジスタを設けるとともに、この制御トラン
ジスタの制御のために、前記オン・オフ信号回路の出力
信号を導かれる遅延回路と、この遅延回路から抵抗を介
して印加される電圧が所定の限界値以上にあるとき導通
して制御トランジスタへのベース電流を通す限界値応動
素子と、前記抵抗と限界値素子との接続点と主トランジ
スタのコレクタとの間に接続され主トランジスタのコレ
クタ・エミッタ間電圧上昇時にのみ遅延回路の出力電圧
により限界値応動素子が導通ずるのを許可するダイオー
ドとを設けることによシ達成される。
According to the present invention, this purpose is to interpose between the base and emitter of the main transistor, which is a switching element, and an on/off signal circuit that controls the main transistor, thereby making it possible to cut off the base forward bias current of the main transistor. In order to increase For this purpose, there is a delay circuit from which the output signal of the on-off signal circuit is guided, and when the voltage applied from this delay circuit through the resistor is above a predetermined limit value, the base current to the control transistor becomes conductive. A limit value responsive element that is connected between the connection point of the resistor and the limit value element and the collector of the main transistor, and is connected to the limit value responsive element by the output voltage of the delay circuit only when the voltage between the collector and emitter of the main transistor increases. This is accomplished by providing a diode that allows the current to conduct.

以下、図面について本発明の実施例を詳細に説明する。Embodiments of the present invention will be described in detail below with reference to the drawings.

第3図は本発明の第一実施例を示す回路図である。オン
・オフ信号回路1の出力端Aは抵抗2を介して主トラン
ジスタ4のベース・エミッタ区間に接続されていて、主
トランジスタ4をオンするための順バイアス電流■!を
供給する。
FIG. 3 is a circuit diagram showing a first embodiment of the present invention. The output terminal A of the on/off signal circuit 1 is connected to the base-emitter section of the main transistor 4 via a resistor 2, and a forward bias current ■! supply.

さらに出力端Aには抵抗10とコンデンサ11で構成す
る遅延回路が並列接続され、この遅延回路の出力端子即
ち抵抗IOとコンデンサ11との接続点は抵抗9を介し
て一つはダイオード6を介して主トランジスタ4のコレ
クタに、他の一つは定電圧ダイオード8を介して制御ト
ランジスタのベースにそれぞれ接続されている。制御ト
ランジスタ5はコレクタを主トランジスタ4のベースに
、エミッタを主トランジスタ4のエミッタに接続されて
いる。ili’l ?fil l・ランンスタ5のベー
ス・エミッタ間ニtrj、抵抗7が並列接続されている
。丑だ主トランジスタ4のベース・エミッタ間には保護
ダイオード3が並列接続されている。
Furthermore, a delay circuit consisting of a resistor 10 and a capacitor 11 is connected in parallel to the output terminal A, and the output terminal of this delay circuit, that is, the connection point between the resistor IO and the capacitor 11 is connected through a resistor 9 and one through a diode 6. One is connected to the collector of the main transistor 4, and the other is connected to the base of the control transistor via a constant voltage diode 8. The control transistor 5 has a collector connected to the base of the main transistor 4 and an emitter connected to the emitter of the main transistor 4. ili'l? A resistor 7 is connected in parallel between the base and emitter of the fil l-run star 5. A protection diode 3 is connected in parallel between the base and emitter of the main transistor 4.

一方、オン・オフ信号回路1の出力端BKは主トランジ
スタ4のベース・エミッタ間か部列接続されておシ、こ
れにょシ主トランジスタ4のターンオン時間を短縮する
ためのベース逆バイアス電流■2を流すことができる。
On the other hand, the output terminal BK of the on/off signal circuit 1 is connected between the base and emitter of the main transistor 4, and the base reverse bias current 2 is used to shorten the turn-on time of the main transistor 4. can flow.

次に動作について説明すると、今オン・オフ信号回路1
の出力端Aにオン信号が出ると、主トランジスタ4のベ
ースからエミッタに順バイアス電流工1が流れ、主トラ
ンジスタ4はオン状態となる。
Next, to explain the operation, now on/off signal circuit 1
When an on signal is output to the output terminal A of the main transistor 4, a forward bias current 1 flows from the base to the emitter of the main transistor 4, and the main transistor 4 is turned on.

この時、主トランジスタ4のコレクタ電流が規定値以下
の場合は、主トランジスタ4のコレクタエミッタ間の電
圧VCJ4)は十分小ざな値となる。
At this time, if the collector current of the main transistor 4 is less than the specified value, the collector-emitter voltage VCJ4) of the main transistor 4 has a sufficiently small value.

この電圧を飽和電圧VcE(scLt)と称する。This voltage is called the saturation voltage VcE (scLt).

一方、数マイクロ秒の時定数を有する抵抗1oとコンデ
ンサ11によシ構成された遅延回路において、コンデン
?110両端電圧は数マイクロ秒後にオンオフ信号回路
lの出力端Aの電圧に近い値丑で充電される。この時、
ダイオード6の順方向電圧Vp(61定屯圧ダイオード
8のツェナー電圧V Z(81、制御トランジスタ5の
ベース・エミッタ間′准圧VBE(5J、およびVcE
(sat)の関係をVc E (5at) + VF(
61(Vz(81十VBE(5)に選定すれば、抵抗9
を流れる電流は全てダイオード6を通って主トランジス
タ4のコレクタに流れ込み・制御1ラン/スタ5のベー
スには電流が流れないので、制御トランジスタ5はオフ
状態となっている。
On the other hand, in a delay circuit composed of a resistor 1o and a capacitor 11 having a time constant of several microseconds, the capacitor? The voltage across the 110 is charged to a value close to the voltage at the output terminal A of the on/off signal circuit 1 after several microseconds. At this time,
Forward voltage Vp of diode 6 (61, constant voltage Zener voltage VZ of diode 8, quasi-voltage VBE (5J, and VcE) between the base and emitter of control transistor 5
(sat) is expressed as Vc E (5at) + VF(
If you select 61 (Vz (81 + VBE (5)), the resistance 9
All current flowing through the diode 6 flows into the collector of the main transistor 4. Since no current flows into the base of the control 1 run/star 5, the control transistor 5 is in an off state.

主トランジスタ4のコレクタ電流が規定値以上すなわち
過電流になると、主トランジスタ4のコレクタ・エミッ
タ間の電圧VCE(4)は飽和電圧VCE(sat、)
よシも大きな値となシ、この電圧の大きさはコレクタ電
流に依存して変化する。この状態を活性状態と称する。
When the collector current of the main transistor 4 exceeds the specified value, that is, becomes an overcurrent, the voltage VCE (4) between the collector and emitter of the main transistor 4 becomes the saturation voltage VCE (sat,).
The magnitude of this voltage varies depending on the collector current, although it is a large value. This state is called an active state.

このような過電流になると、VCE + Vp(6))
Vz(8)+ VBE (5)となシ、制御トランジス
タ5はスイッチオンの状態となる。
When such an overcurrent occurs, VCE + Vp(6))
When Vz(8)+VBE(5), the control transistor 5 is switched on.

その結果、主トランジスタ4のベースからエミッタに流
れていた電流工1は制御トランジスタ5に転流し、主ト
ランジスタ4はオフとなる。この時、主トランジスタ4
は活性状態からオフ状態へと移行するので、はとんど時
間的遅れは生じない。
As a result, the current 1 flowing from the base to the emitter of the main transistor 4 is diverted to the control transistor 5, and the main transistor 4 is turned off. At this time, main transistor 4
transitions from the active state to the off state, so there is almost no time delay.

次に、オン・オフ信号回路1の出力端Aのオン信号がな
くなシ、出力端Bにオフ信号が出ると、主トランジスタ
4のベース・エミッタ間ハベース電位が負、エミッタ電
位が正の状態となる。この状態をベース逆バイアス状態
と称する。この時、遅延回路を構成しているコンデンサ
■1は放電状態となシ、次のオン・オフ信号回路1の出
力端Aのオン信号の時に必要な遅延時間が確保でき、主
トランジスタ4の確実なオン動作は保証される。すなわ
ち、この遅延がなければ、主トランジスタ4がオンする
以前に先に制御トランジスタ5がオンし、これがため主
トランジスタ4がオンすることができなくなるが、これ
を回避できるのである。
Next, when the ON signal at the output terminal A of the ON/OFF signal circuit 1 disappears and the OFF signal is output at the output terminal B, the base potential between the base and emitter of the main transistor 4 is negative, and the emitter potential is positive. becomes. This state is called a base reverse bias state. At this time, the capacitor 1 constituting the delay circuit is not in a discharged state, so that the delay time necessary for the next on signal at the output terminal A of the on/off signal circuit 1 can be secured, and the main transistor 4 can be On-operation is guaranteed. That is, without this delay, the control transistor 5 would turn on before the main transistor 4 turns on, which would prevent the main transistor 4 from turning on, but this can be avoided.

なお、制御トランジスタ5のベース・エミッタ間に並列
接続した抵抗7は、定電圧ダイオード8のツェナー電圧
補償用である。
Note that a resistor 7 connected in parallel between the base and emitter of the control transistor 5 is used to compensate for the Zener voltage of the constant voltage diode 8.

また、ここに使用している定電圧ダイオード8は、整流
用ダイオードの直列接続に、制御トランジスタ5はサイ
リスクやF E Tなと他の半導体装置換えることも可
能である。
Further, the constant voltage diode 8 used here can be replaced with a series connection of rectifying diodes, and the control transistor 5 can be replaced with another semiconductor device such as Cyrisk or FET.

第4図は本発明の第2実施例を示す回路図で、前記第6
図と異なる点は、オン・オフ信号回路1内に設けられて
いるパルス電圧平滑回路を遅延回路として流用したもの
である。既に述べたように、オン・オフ信号回路として
使用することのできる特開昭、r? −1&+21号記
載のベース駆動回路によれば、ベース順バイアス電流供
給のための回路部分はオン指令期間中間断なく連続する
パルス電圧を発生する必要がるシ、このために絶縁トラ
ンスを大形化するという問題を解決している。
FIG. 4 is a circuit diagram showing a second embodiment of the present invention.
The difference from the diagram is that the pulse voltage smoothing circuit provided in the on/off signal circuit 1 is used as a delay circuit. As already mentioned, JP-A-Sho, r?, which can be used as an on/off signal circuit. According to the base drive circuit described in No.-1 & +21, the circuit part for supplying forward bias current to the base needs to generate a continuous pulse voltage without interruption during the on-command period, and for this purpose, the isolation transformer is made large. It solves the problem of

第5図は本発明の第6実施例を示す回路図で、主トラン
ジスタ4へのベース電流供給用直流電源12をオン・オ
フ信号回路1とは別に準備したものである。制御トラン
ジスタ5の他にオン用トランジスタ15とオフ用トラン
ジスタ16とを相互に接続して主トランジスタ4のベー
ス駆動回路に挿入し+:s 、 j−+ fqj21.
それぞれ電源12とトランジスタ15゜1(1の工(ツ
ク間に挿入された抵抗を示す。
FIG. 5 is a circuit diagram showing a sixth embodiment of the present invention, in which a DC power supply 12 for supplying base current to the main transistor 4 is prepared separately from the on/off signal circuit 1. In addition to the control transistor 5, an ON transistor 15 and an OFF transistor 16 are connected to each other and inserted into the base drive circuit of the main transistor 4.
The resistor inserted between the power supply 12 and the transistor 15°1 is shown.

このように回路構成した場合、オン・オフ信号同1洛1
の出力信号が高レベル(直流電源12のPの電位少の時
、トランジスタ15がオン、トランジスタ10がオフと
なシ、主トランジスタ4はオンとなる。一方、オン・オ
フ信号回路lの出力信号が低レベル(直流電源12のN
の電位〕の時、トランジスタJ5がオフ、トランジスタ
16がオンとなシ、主トランジスタ4はオフとなる。
When the circuit is configured like this, the on/off signals are the same.
The output signal of is at a high level (when the potential of P of the DC power supply 12 is low, the transistor 15 is on, the transistor 10 is off, and the main transistor 4 is on. On the other hand, the output signal of the on/off signal circuit l is is low level (DC power supply 12 N
, the transistor J5 is off, the transistor 16 is on, and the main transistor 4 is off.

過電流時の動作は前記第3図と第1実施例と同様である
が、制御トランジスタ5は直接主トランジスタ・1のベ
ース電流を制御しないので電流′8量の小さなものです
み、回路全体が小形で低価格なものとなる。
The operation at the time of overcurrent is the same as that shown in FIG. It is small and inexpensive.

第6図は本発明の第4実施例を示す回路図で、主回路が
ダーリントン接続した主トランジスタ4と前段のトラン
ジスタJ7とで構成された場合である。図中18はトラ
ンジスタ17の保護ダイオードを示す。
FIG. 6 is a circuit diagram showing a fourth embodiment of the present invention, in which the main circuit is composed of a Darlington-connected main transistor 4 and a preceding transistor J7. In the figure, 18 indicates a protection diode for the transistor 17.

この場合、オン状態での主トランジスタ4のコレクタ・
エミッタ間電圧VCE(411’j:主トランジスタ4
のベース・エミッタ間電圧をVBE(41、前段トラン
ジスタ17のコレクタ・エミッタ間電圧をVCE(lη
とすると、VCE (2) −VBE (2) + V
CE an (!: 7Z ル。
In this case, the collector of the main transistor 4 in the on state
Emitter voltage VCE (411'j: main transistor 4
The voltage between the base and emitter of
Then, VCE (2) −VBE (2) + V
CE an (!: 7Z le.

過電流時、主トランジスタ4のベース・エミッタ間電圧
VB141(7)変化はVCE(2+、VCEQηの変
化に比べて非常に小さいものとなる。このため、本実施
例では前段トランジスタ17のコレクタ・エミッタ間電
圧VCE(+7+を監視し、規定値以上にこの電圧が大
きくなった場合に制御トランジスタ5をオンさせ、主ト
ランジスタ4を遮断するようにすればよい。このように
すれば、前段トランジスタ17だけをオン・オフ信号回
路1で駆動するので駆動容量が少なくてすむ。
At the time of overcurrent, the change in the base-emitter voltage VB141(7) of the main transistor 4 is very small compared to the change in VCE(2+, VCEQη. Therefore, in this embodiment, the collector-emitter voltage of the front-stage transistor 17 It is sufficient to monitor the voltage between VCE (+7+) and turn on the control transistor 5 and cut off the main transistor 4 when this voltage becomes larger than a specified value. Since it is driven by the on/off signal circuit 1, the driving capacity can be reduced.

以上述べたように本発明のトランジスタの過電流保護回
路は、スイッチング素子たる主トランジスタのコレクタ
・エミッタ間の電圧が過電流時に大きくなることを利用
して、この電圧が規定値以jに請願し/ごときに瞬時に
主トランジスタのペース化?Z1.を遮断する回路を付
加したので、従来のようt’c :’IE回路に電流検
出器や電流検出用抵抗を用いる必要がなくなシ安価な回
路構成でしかも主回路のjJ1失の少ないものとなシ、
また電流の時間的変化か急峻なトランジスタの過電流を
確実に保護できる信頼性の高いものが得られる。
As described above, the transistor overcurrent protection circuit of the present invention takes advantage of the fact that the voltage between the collector and emitter of the main transistor, which is a switching element, increases when there is an overcurrent. / Instantly pace the main transistor? Z1. Since a circuit is added to cut off the t'c:', there is no need to use a current detector or current detection resistor in the t'c:'IE circuit as in the past.It is an inexpensive circuit configuration and has less jJ1 loss in the main circuit. Nasi,
In addition, a highly reliable device that can reliably protect against temporal changes in current or sudden overcurrent of a transistor can be obtained.

【図面の簡単な説明】[Brief explanation of drawings]

第1図、第2図はそれぞれ従来例を示す回路図、第6図
は本発明の第1実施例を示す回路図、第4図は向上第2
実施例を示す回路図、第5図は同上第3実施例を示す回
路図、第6図は同上第4実施例を示す回路図である。 1・・・・・・オン・オフ信号回路 lα・・・・・・
遅延回路2・・・・・電流制限抵抗  3・・・・・・
保護ダイオード・1・・・・・・主トランジスタ 5・
・・・・・制御トランジスタ6・・・・・ダイオード 
  7・・・・・・抵抗8・・・・・定電圧ダイオード
 9,1o・・・用抵抗1j  ・・コンデンサ   
12・・・・・・直流電源1:i 、 14・・・抵抗
    15.16・旧・・トランジスタ17・・・・
・前段トランジスタ  18・・・・・ダイオード代理
人  弁理士 久 保  司 第1図 第2図 第3図 第4図
1 and 2 are circuit diagrams showing conventional examples, FIG. 6 is a circuit diagram showing a first embodiment of the present invention, and FIG. 4 is a circuit diagram showing an improved second embodiment.
FIG. 5 is a circuit diagram showing the third embodiment, and FIG. 6 is a circuit diagram showing the fourth embodiment. 1...On/off signal circuit lα...
Delay circuit 2...Current limiting resistor 3...
Protection diode 1... Main transistor 5.
... Control transistor 6 ... Diode
7... Resistor 8... Constant voltage diode 9, 1o... Resistor 1j... Capacitor
12...DC power supply 1:i, 14...Resistor 15.16 Old...Transistor 17...
・Pre-stage transistor 18... Diode agent Patent attorney Tsukasa Kubo Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

【特許請求の範囲】[Claims] スイッチング素子たる主トランジスタのベース・エミッ
タ間とその主トランジスタを制御するオン・オフ信号回
路との間に介在し、主トランジスタのベース順バイアス
電流の遮断を可能にすべく、主トランジスタのベース・
エミッタ間を直接的に橋絡するかもしくは主トランジス
タにベース順バイアス電流を導く補助トランジスタのベ
ース・エミッタ間を橋絡する制御トランジスタを設ける
とともに、この制御トランジスタの制御のために、前記
オン・オフ信号回路の出力信号を導−かれる遅延回路と
、この遅延回路から抵抗を介して印加される電圧が所定
の限界値以上にあるとき導通して制御トランジスタへの
ベース電流を通す限界値応動素子と、前記抵抗と限界値
素子との接続点と主トランジスタのコレクタとの間に接
続それ主トランジスタのコレクタ・エミッタ間電圧上昇
時にのみ遅延回路の出力電圧によシ限界値応動素子が導
通するのを許可するダイオードとを設けたことを特徴と
するトランジスタの過電流保護回路。
It is interposed between the base and emitter of the main transistor, which is a switching element, and the on/off signal circuit that controls the main transistor.
A control transistor is provided that directly bridges the emitter or bridges between the base and emitter of the auxiliary transistor that guides the base forward bias current to the main transistor, and in order to control this control transistor, the on/off a delay circuit to which an output signal of the signal circuit is guided; and a limit value sensitive element that becomes conductive and passes base current to the control transistor when the voltage applied from the delay circuit via the resistor exceeds a predetermined limit value. , is connected between the connection point between the resistor and the limit value element and the collector of the main transistor so that the limit value responsive element becomes conductive depending on the output voltage of the delay circuit only when the voltage between the collector and emitter of the main transistor increases. 1. A transistor overcurrent protection circuit, characterized in that a transistor overcurrent protection circuit is provided with a diode.
JP57210885A 1982-12-01 1982-12-01 Overcurrent protecting circuit for transistor Granted JPS59103567A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP57210885A JPS59103567A (en) 1982-12-01 1982-12-01 Overcurrent protecting circuit for transistor
DE19833343201 DE3343201A1 (en) 1982-12-01 1983-11-29 Overcurrent protection circuit for a transistor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP57210885A JPS59103567A (en) 1982-12-01 1982-12-01 Overcurrent protecting circuit for transistor

Publications (2)

Publication Number Publication Date
JPS59103567A true JPS59103567A (en) 1984-06-15
JPH0243429B2 JPH0243429B2 (en) 1990-09-28

Family

ID=16596699

Family Applications (1)

Application Number Title Priority Date Filing Date
JP57210885A Granted JPS59103567A (en) 1982-12-01 1982-12-01 Overcurrent protecting circuit for transistor

Country Status (2)

Country Link
JP (1) JPS59103567A (en)
DE (1) DE3343201A1 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61147736A (en) * 1984-12-19 1986-07-05 日立精工株式会社 Switching element drive circuit
JPS62138013A (en) * 1985-12-09 1987-06-20 ヒユ−ズ ツ−ル カンパニ− Power transistor overcurrent protection circuit
JPS62125912U (en) * 1986-01-29 1987-08-10
JPS63177612A (en) * 1987-01-19 1988-07-21 Toshiba Corp gate control circuit
JP2008091057A (en) * 2006-09-29 2008-04-17 Matsushita Electric Ind Co Ltd Induction heating cooker
JP2014187443A (en) * 2013-03-22 2014-10-02 Nissin Electric Co Ltd Drive circuit
JP2017224999A (en) * 2016-06-15 2017-12-21 富士電機株式会社 Protection circuit of semiconductor switching element

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6258827A (en) * 1985-09-03 1987-03-14 株式会社日立製作所 Overcurrent protection system for transistor
EP0328905B1 (en) * 1988-02-15 1994-06-29 Siemens Aktiengesellschaft Circuit arrangement for the protection of an integrated circuit
JPH0766958B2 (en) * 1989-03-20 1995-07-19 株式会社東芝 Electrostatic protection circuit
DE202006002761U1 (en) * 2006-02-21 2006-06-01 Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH High-speed driver with minimum switching frequency

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3104015C2 (en) * 1981-02-05 1984-10-11 Siemens AG, 1000 Berlin und 8000 München Overcurrent protection arrangement for a semiconductor switch

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61147736A (en) * 1984-12-19 1986-07-05 日立精工株式会社 Switching element drive circuit
JPS62138013A (en) * 1985-12-09 1987-06-20 ヒユ−ズ ツ−ル カンパニ− Power transistor overcurrent protection circuit
JPS62125912U (en) * 1986-01-29 1987-08-10
JPS63177612A (en) * 1987-01-19 1988-07-21 Toshiba Corp gate control circuit
JP2008091057A (en) * 2006-09-29 2008-04-17 Matsushita Electric Ind Co Ltd Induction heating cooker
JP2014187443A (en) * 2013-03-22 2014-10-02 Nissin Electric Co Ltd Drive circuit
JP2017224999A (en) * 2016-06-15 2017-12-21 富士電機株式会社 Protection circuit of semiconductor switching element

Also Published As

Publication number Publication date
JPH0243429B2 (en) 1990-09-28
DE3343201A1 (en) 1984-06-07

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