JPH0510846B2 - - Google Patents
Info
- Publication number
- JPH0510846B2 JPH0510846B2 JP59097923A JP9792384A JPH0510846B2 JP H0510846 B2 JPH0510846 B2 JP H0510846B2 JP 59097923 A JP59097923 A JP 59097923A JP 9792384 A JP9792384 A JP 9792384A JP H0510846 B2 JPH0510846 B2 JP H0510846B2
- Authority
- JP
- Japan
- Prior art keywords
- transistor
- base
- diode
- power supply
- current
- 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
Links
- 238000010586 diagram Methods 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/08—Modifications for protecting switching circuit against overcurrent or overvoltage
- H03K17/081—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit
- H03K17/0812—Modifications 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
- H03K17/08126—Modifications 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
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
- H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
- H03K17/60—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being bipolar transistors
- H03K17/615—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being bipolar transistors in a Darlington configuration
Landscapes
- Electronic Switches (AREA)
Description
【発明の詳細な説明】
〔発明の技術分野〕
この発明は、トランジスタのベース駆動回路に
関し、特に負荷短絡事故等の過電流が流れたとき
に被駆動トランジスタのベース電流を抑制あるい
は遮断し、該トランジスタを保護するためのベー
ス駆動回路に関するものである。[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a base drive circuit for a transistor, and in particular, when an overcurrent such as a load short circuit occurs, the base current of the driven transistor is suppressed or cut off. This invention relates to a base drive circuit for protecting transistors.
従来、この種の装置として第１図に示すものが
あつた。図において、１，２は第１、第２のトラ
ンジスタ、５は抵抗、６は主トランジスタ（被駆
動トランジスタ）である。トランジスタ１は主ト
ランジスタ６に正バイアスを与えるための電源
Vccに接続され、トランジスタ２は主トランジス
タ６に負バイアスを与えるための電源VEEに接
続される。これらトランジスタ１と２は直列に接
続され、その接続点は抵抗５を介して主トランジ
スタ６のベースに接続される。
Conventionally, there has been a device of this type as shown in FIG. In the figure, 1 and 2 are first and second transistors, 5 is a resistor, and 6 is a main transistor (driven transistor). Transistor 1 is a power supply for providing positive bias to main transistor 6
Vcc, and transistor 2 is connected to a power supply VEE for providing negative bias to main transistor 6. These transistors 1 and 2 are connected in series, and their connection point is connected to the base of the main transistor 6 via a resistor 5.
ここでトランジスタ１と２は交互に動作するよ
うにそれぞれベース信号が入力される。まずトラ
ンジスタ１のベースに信号が入力されるとトラン
ジスタ１はオンし、抵抗５を介して主トランジス
タ６のベースに順電流を流す。このとき主トラン
ジスタ６はオンする。次にトランジスタ１のベー
ス信号が遮断されるとこれと同時にトランジスタ
２のベースに信号が入力され、トランジスタ１は
オフしトランジスタ２がオンする。このときトラ
ンジスタ６はベース・エミツタ間が逆バイアスさ
れターンオフする。 Here, transistors 1 and 2 each receive a base signal so that they operate alternately. First, when a signal is input to the base of transistor 1, transistor 1 is turned on, and a forward current flows through resistor 5 to the base of main transistor 6. At this time, the main transistor 6 is turned on. Next, when the base signal of transistor 1 is cut off, a signal is simultaneously input to the base of transistor 2, transistor 1 is turned off and transistor 2 is turned on. At this time, the base and emitter of the transistor 6 are reverse biased and turned off.
従来のトランジスタのベース駆動回路は以上の
ように構成されており、トランジスタ１がオンし
主トランジスタ６が導通期間となつたときに負荷
短絡等の事故により該トランジスタ６のコレクタ
電流が過電流になつたとき、該トランジスタ６が
破壊されてしまう欠点があつた。 The conventional transistor base drive circuit is configured as described above, and when the transistor 1 is turned on and the main transistor 6 is in the conduction period, the collector current of the transistor 6 becomes an overcurrent due to an accident such as a load short circuit. There was a drawback in that the transistor 6 was destroyed when
この発明は、上記のような従来のものの欠点を
除去するためになされたもので、主トランジスタ
のベースと該トランジスタを逆バイアスするため
のトランジスタのベース間にダイオードと定電圧
素子とを直列に挿入することにより、主トランジ
スタの短絡保護を容易に行えるトランジスタのベ
ース駆動回路を提供することを目的としている。
This invention was made to eliminate the drawbacks of the conventional ones as described above, and a diode and a constant voltage element are inserted in series between the base of a main transistor and the base of a transistor for reverse biasing the transistor. It is an object of the present invention to provide a transistor base drive circuit that can easily protect the main transistor from short-circuiting.
以下、この発明の実施例を図について説明す
る。
Embodiments of the present invention will be described below with reference to the drawings.
第２図は本発明の一実施例によるトランジスタ
のベース駆動回路を示す。図において、第１図と
同一の符号は同一のものを示す。本実施例回路は
トランジスタ２のベースと主トランジスタ６のベ
ースとの間にダイオード４とツエナーダイオード
３の直列回路が付加されている。 FIG. 2 shows a transistor base drive circuit according to one embodiment of the present invention. In the figure, the same reference numerals as in FIG. 1 indicate the same parts. In the circuit of this embodiment, a series circuit of a diode 4 and a Zener diode 3 is added between the base of the transistor 2 and the base of the main transistor 6.
次に動作について説明する。本実施例回路の正
常動作時の動作は従来のものと同様である。今ト
ランジスタ１がオンし主トランジスタ６の導通期
間に負荷短絡等の事故により該トランジスタ６の
コレクタ電流が過電流になつたとする。このとき
そのベース・エミツタ間の電圧がコレクタ電流の
増加に応じて上昇するが、定格コレクタ電流と、
コレクタ電流の過電流領域との間の、主トランジ
スタの保護のための適切な所定値のコレクタ電流
に対応するベース・エミツタ間電圧（VBE）を、
ツエナーダイオード３の逆耐圧とダイオード４の
順方向電圧（VF）との和にほぼ等しくなるよう
に設定しておけば、ツエナーダイオード３にアバ
ランシエ電流が流れトランジスタ２が導通する。
該トランジスタ２が導通するとトランジスタ１か
ら流れ出る電流がトランジスタ２にバイパスさ
れ、主トランジスタのベース電流が抑制あるいは
遮断されるため、主トランジスタ６は遮断される
か、あるいはコレクタ電流が著しく抑制され、こ
れにより、主トランジスタは破壊から保護され
る。 Next, the operation will be explained. The operation of the circuit of this embodiment during normal operation is similar to that of the conventional circuit. Suppose that the transistor 1 is turned on and the collector current of the transistor 6 becomes an overcurrent due to an accident such as a load short circuit during the conduction period of the main transistor 6. At this time, the voltage between its base and emitter increases as the collector current increases, but the rated collector current and
The base-emitter voltage (VBE) corresponding to a predetermined value suitable for protection of the main transistor between the overcurrent region of the collector current and the collector current,
If it is set to be approximately equal to the sum of the reverse breakdown voltage of the Zener diode 3 and the forward voltage (VF) of the diode 4, an avalanche current flows through the Zener diode 3 and the transistor 2 becomes conductive.
When the transistor 2 becomes conductive, the current flowing from the transistor 1 is bypassed to the transistor 2, and the base current of the main transistor is suppressed or cut off, so that the main transistor 6 is cut off or the collector current is significantly suppressed. , the main transistor is protected from destruction.
このように、本実施例によれば、主トランジス
タの短絡保護を、ツエナーダイオードとダイオー
ドによる簡単な回路にて容易に行える効果があ
る。 As described above, according to this embodiment, short-circuit protection of the main transistor can be easily performed using a simple circuit using a Zener diode and a diode.
以上のように、この発明によれば、ダイオード
と定電圧素子による非常に簡単な回路を付加し、
これにより主トランジスタの短絡電流を検出し、
そのベース電流を抑制あるいは遮断するようにし
たので、短絡事故時の主トランジスタの保護が可
能となる効果がある。
As described above, according to the present invention, a very simple circuit consisting of a diode and a constant voltage element is added,
This detects the short circuit current of the main transistor,
Since the base current is suppressed or cut off, the main transistor can be protected in the event of a short circuit accident.
第１図は従来のトランジスタのベース駆動回路
の回路図、第２図は本発明の一実施例の回路図で
ある。
図中、１は第１のトランジスタ、２は第２のト
ランジスタ、３はツエナーダイオード（定電圧素
子）、４はダイオード、５は抵抗、６は主トラン
ジスタ（被駆動トランジスタ）、Vccは第１の電
源、VEEは第２の電源である。
FIG. 1 is a circuit diagram of a conventional transistor base drive circuit, and FIG. 2 is a circuit diagram of an embodiment of the present invention. In the figure, 1 is the first transistor, 2 is the second transistor, 3 is the Zener diode (constant voltage element), 4 is the diode, 5 is the resistor, 6 is the main transistor (driven transistor), and Vcc is the first transistor. The power supply, VEE, is the second power supply.
Claims (1)
バイアスを与えるための第２の電源と、 上記第１、第２の電源間に直列接続された第
１、第２のトランジスタと、 ベースが上記第１、第２のトランジスタの接続
点に接続された被駆動トランジスタとを備えたト
ランジスタのベース駆動回路において、 上記第２のトランジスタと上記被駆動トランジ
スタの両ベース間に相互に直列接続されたダイオ
ードおよび定電圧素子を備え、 上記被駆動トランジスタのコレクタ電流が定格
電流を越える所定値において、上記被駆動トラン
ジスタのベース電流が上記定電圧素子と上記ダイ
オードとを介して上記第２のトランジスタにより
バイパスされるようにしたことを特徴とするトラ
ンジスタのベース駆動回路。[Claims] 1. A first power supply for providing a positive bias, a second power supply for providing a negative bias, and a first and second power supply connected in series between the first and second power supplies. and a driven transistor whose base is connected to the connection point of the first and second transistors, wherein: between the bases of the second transistor and the driven transistor; A diode and a constant voltage element are connected in series with each other, and at a predetermined value where the collector current of the driven transistor exceeds the rated current, the base current of the driven transistor flows through the constant voltage element and the diode. A transistor base drive circuit, characterized in that it is bypassed by a second transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59097923A JPS60239119A (en) | 1984-05-14 | 1984-05-14 | Base drive circuit of transistor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59097923A JPS60239119A (en) | 1984-05-14 | 1984-05-14 | Base drive circuit of transistor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60239119A JPS60239119A (en) | 1985-11-28 |
| JPH0510846B2 true JPH0510846B2 (en) | 1993-02-10 |
Family
ID=14205206
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59097923A Granted JPS60239119A (en) | 1984-05-14 | 1984-05-14 | Base drive circuit of transistor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60239119A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4736569B2 (en) * | 2005-07-01 | 2011-07-27 | 株式会社デンソー | Inductive load abnormality detection device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54131857A (en) * | 1978-04-04 | 1979-10-13 | Toshiba Corp | Transistor dc switching device |
-
1984
- 1984-05-14 JP JP59097923A patent/JPS60239119A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54131857A (en) * | 1978-04-04 | 1979-10-13 | Toshiba Corp | Transistor dc switching device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60239119A (en) | 1985-11-28 |
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