JPS6122762A - Overcurrent protecting circuit - Google Patents

Overcurrent protecting circuit

Info

Publication number
JPS6122762A
JPS6122762A JP59139092A JP13909284A JPS6122762A JP S6122762 A JPS6122762 A JP S6122762A JP 59139092 A JP59139092 A JP 59139092A JP 13909284 A JP13909284 A JP 13909284A JP S6122762 A JPS6122762 A JP S6122762A
Authority
JP
Japan
Prior art keywords
circuit
thyristor
photocoupler
inverter
resistor
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
Application number
JP59139092A
Other languages
Japanese (ja)
Inventor
Shinobu Kake
忍 懸
Hisashi Kinoshita
木下 久
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial 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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP59139092A priority Critical patent/JPS6122762A/en
Publication of JPS6122762A publication Critical patent/JPS6122762A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • H02M7/00Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Ac Motors In General (AREA)
  • Inverter Devices (AREA)
  • Protection Of Static Devices (AREA)

Abstract

PURPOSE:To improve the quality by detecting an overcurrent flowed to an inverter and a bridge circuit by a photocoupler or the like circuit at the prescribed value to turn OFF a switching element, thereby preventing the element from damaging. CONSTITUTION:An inverter for pulse-width-modulating via power transistors 2- 7 is formed, and has a base controller 14 and a controller 15 for controlling to pulse-width-modulate it. The current flowed to the inverter is detected by current detecting resistor 17 and photocouplers 19, 20. Thus, when an overcurrent flows, the photocoupler is turned ON, and a thyristor 27 is turned ON by conducting the photoreceiving side 20. The signal of the base controller 14 is broken by the thyristor 27, and the transistors 2-7 are turned OFF. The irregularity of the gate sensitivity of the thyristor 27 is regulated by altering the resistance value of the resistor 23, and the operating point of the overcurrent protecting circuit is maintained constantly.

Description

【発明の詳細な説明】 (産業上の利用分野) 本発明は、スイッチング素子を使用してパルス幅変調制
御するインバータ回路およびブリッジ回路の保護を行な
う過電流保護回路に関するものである。
DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an overcurrent protection circuit that protects an inverter circuit and a bridge circuit that perform pulse width modulation control using switching elements.

(従来例の構成とその問題点) 第1図は、従来のインバータ回路の主回路の構成を示す
もので、1はモータ、2〜7はパワートランジスタで、
パルス幅変調を行なうインバータ回路を構成し、8〜1
3はフリーホイールダイオード、14は各パワートラン
ジスタ2〜7を制御するベース制御回路、15はベース
制御回路14をパルス幅変調制御する制御回路、16は
直流電源である。
(Conventional configuration and its problems) Figure 1 shows the configuration of the main circuit of a conventional inverter circuit, where 1 is a motor, 2 to 7 are power transistors,
8 to 1 constitute an inverter circuit that performs pulse width modulation.
3 is a freewheel diode, 14 is a base control circuit that controls each of the power transistors 2 to 7, 15 is a control circuit that controls the base control circuit 14 by pulse width modulation, and 16 is a DC power supply.

第2図は、従来のブリッジ回路の主回路の構成を示すも
ので、スイッチング素子を使用してパルス幅変調制御す
るものであり、第1図と同一符号は同一のものを示して
いる。ここでパワートランジスタ2〜5はパルス幅変調
制御を行なうブリッジ回路を構成している。
FIG. 2 shows the configuration of the main circuit of a conventional bridge circuit, which performs pulse width modulation control using switching elements, and the same reference numerals as in FIG. 1 indicate the same components. Here, the power transistors 2 to 5 constitute a bridge circuit that performs pulse width modulation control.

しかしながら、上記の従来例では、パワー−トランジス
タ2と3.4と5または6と7とが同時にオン状態にな
ると、直流電圧が短絡されて過電流が流れるので、−瞬
のうちにパワートランジスタ2〜7が破壊される等の欠
点があった。
However, in the above conventional example, if power transistors 2, 3, 4, 5 or 6 and 7 are turned on at the same time, the DC voltage is short-circuited and an overcurrent flows. -7 were destroyed.

(発明の目的) 本発明は、上記従来例の欠点に鑑みてなされたもので、
スイッチング素子の破損を防止したインバータ回路およ
びブリッジ回路の過電流保護回路を提供瞥ようとするも
のである。
(Object of the invention) The present invention has been made in view of the drawbacks of the above-mentioned conventional examples, and
The present invention aims to provide an overcurrent protection circuit for inverter circuits and bridge circuits that prevents damage to switching elements.

(発明の構成) この目的を達成するために本発明は、6個のスイッチン
グ素子よりなり、パルス幅変調制御インバータ回路と、
そのインバータ回路に供給する直流電源に直列に接続さ
れた電流検出用抵抗と、その電流検出用抵抗と並列接続
した抵抗とホトカプラの発光側の直列回路と、前記ホト
カプラの受光側に直列に接続した出力電流を分流する可
変可能な分流回路とサイリスタのゲート回路の並列回路
と、前記サイリスタの出力により前記スイッチング素子
をオフする手段とからなり、インバータ回路に流れる過
電流を防止するように構成したものである。
(Structure of the Invention) In order to achieve this object, the present invention includes a pulse width modulation control inverter circuit, which includes six switching elements, and a pulse width modulation control inverter circuit.
A current detection resistor connected in series with the DC power supply supplied to the inverter circuit, a resistor connected in parallel with the current detection resistor, a series circuit on the light emitting side of the photocoupler, and a series circuit connected in series on the light receiving side of the photocoupler. A parallel circuit consisting of a variable shunt circuit that shunts an output current and a thyristor gate circuit, and means for turning off the switching element using the output of the thyristor, and is configured to prevent overcurrent flowing into the inverter circuit. It is.

(実施例の説明) 第3図は、本発明の構成を示す一実施例の回路図であり
、第1図と同一符号は同一部分を示し、17はインバー
タ回路に流れる電流を検出する電流検出用抵抗、18は
電流制限用抵抗、19はホ1へカブラの発光側、20は
ホトカプラの受光側、21は誤動作防止のためのコンデ
ンサ、22は前記ホトカプラの発光側19の逆電圧保護
用のダイオード、23は保護回路の動作点を調整するた
めの可変抵抗器、24は電流制限用抵抗、25は誤動作
防止のためのコンデンサ、26は抵抗、27はサイリス
タである。
(Description of Embodiment) FIG. 3 is a circuit diagram of an embodiment showing the configuration of the present invention, where the same reference numerals as in FIG. 18 is a current limiting resistor, 19 is the light emitting side of the photocoupler, 20 is the light receiving side of the photocoupler, 21 is a capacitor for preventing malfunction, 22 is a reverse voltage protection resistor on the light emission side 19 of the photocoupler. A diode, 23 is a variable resistor for adjusting the operating point of the protection circuit, 24 is a current limiting resistor, 25 is a capacitor for preventing malfunction, 26 is a resistor, and 27 is a thyristor.

ここで、電流制限用抵抗18はホトカプラの発光側19
に流れる電流の制限を行ない、電流制限用紙     
−抗24はサイリスタ27のゲートに流れる電流を制限
する。また、コンデンサ25はサイリスタ27の誤動作
防止を行ない、抵抗26はサイリスタ27のゲートに加
わる電圧のレベルを安定化するためのものである。
Here, the current limiting resistor 18 is the light emitting side 19 of the photocoupler.
Limit the current flowing through the
- resistor 24 limits the current flowing to the gate of thyristor 27; Further, the capacitor 25 prevents the thyristor 27 from malfunctioning, and the resistor 26 stabilizes the level of the voltage applied to the gate of the thyristor 27.

次に、本発明の動作か説明する。パワートランジスタ2
と3.4と5、または6と7が同時にオン状態になり、
過電流が流れると、電流検出用抵抗17の両端に大電圧
が発生する。この電圧が電流制限用抵抗18を介してホ
トカプラの発光側19に掛り、ホトカプラがオンする。
Next, the operation of the present invention will be explained. power transistor 2
and 3.4 and 5 or 6 and 7 are turned on at the same time,
When an overcurrent flows, a large voltage is generated across the current detection resistor 17. This voltage is applied to the light emitting side 19 of the photocoupler via the current limiting resistor 18, turning on the photocoupler.

さらに、ホトカプラの受光側20が導通しサイリスタ2
7のゲートに電流が流れ、サイリスタ27がオンする。
Furthermore, the light receiving side 20 of the photocoupler is electrically connected to the thyristor 2.
A current flows through the gate of thyristor 27, and thyristor 27 is turned on.

そして、サイリスタ27の出力信号によってベース制御
回路14の信号を遮断し、パワートランジスタ2,3,
4,5.6および7のベース入力を遮断してパワートラ
ンジスタ2,3,4,5.6および7をオフ状態にする
。可変抵抗器23は、ホトカプラの発光側19の順電圧
と、ホトカプラの受光側20の受光感度と、サイリスタ
27のゲート感度のばらつきを、可変抵抗器23の抵抗
値を変化することによって調整し、過電流保護回路の動
作点を一定にすることが出来る可変抵抗器である。よっ
て、直流電圧の短絡を防止し、インバータ回路を保護す
ることが出来る。
Then, the signal of the base control circuit 14 is cut off by the output signal of the thyristor 27, and the power transistors 2, 3,
The base inputs of power transistors 2, 3, 4, 5.6 and 7 are turned off by cutting off the base inputs of transistors 2, 3, 4, 5.6 and 7. The variable resistor 23 adjusts variations in the forward voltage on the light emitting side 19 of the photocoupler, the light receiving sensitivity on the light receiving side 20 of the photocoupler, and the gate sensitivity of the thyristor 27 by changing the resistance value of the variable resistor 23. This is a variable resistor that can keep the operating point of the overcurrent protection circuit constant. Therefore, it is possible to prevent a short circuit of the DC voltage and protect the inverter circuit.

(発明の効果) 以上説明したように、本発明は、インバータ回路および
ブリッジ回路に流れる過電流を、僅かな部品点数で構成
された回路によって一定値で検出し、スイッチング素子
をオフするもので、スイッチング素子の破損を防止し、
インバータ回路およびブリッジ回路を保護して、品質を
向上させるものである。
(Effects of the Invention) As explained above, the present invention detects overcurrent flowing through an inverter circuit and a bridge circuit at a constant value using a circuit configured with a small number of parts, and turns off a switching element. Prevents damage to switching elements,
It protects inverter circuits and bridge circuits and improves their quality.

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

第1図は、従来のインバータ回路の主回路の構成を示す
図、第2図は、従来のブリッジ回路の主回路の構成を示
す図、第3図は、本発明の構成を示す一実施例の回路図
である。 1 ・・・モータ、2〜7 ・・・パワートランジスタ
、8〜13・・・ フリーホイールダイオード、14・
・・ベース制御回路、15・・・制御回路、16・・・
直流電源、17・・・電流検出用抵抗、18・・・電流
制限用抵抗、19.20・・・ホトカプラ、21.25
・・・コンデンサ、22・・・ダイオード、23・・・
可変抵抗器、24.26・・・抵抗、27・・・サイリ
スタ。 第1図 第2図
FIG. 1 is a diagram showing the configuration of the main circuit of a conventional inverter circuit, FIG. 2 is a diagram showing the configuration of the main circuit of a conventional bridge circuit, and FIG. 3 is an embodiment showing the configuration of the present invention. FIG. 1...Motor, 2-7...Power transistor, 8-13...Freewheel diode, 14.
...Base control circuit, 15...Control circuit, 16...
DC power supply, 17... Resistor for current detection, 18... Resistor for current limiting, 19.20... Photocoupler, 21.25
...Capacitor, 22...Diode, 23...
Variable resistor, 24.26...Resistor, 27...Thyristor. Figure 1 Figure 2

Claims (2)

【特許請求の範囲】[Claims] (1)6個のスイッチング素子よりなり、パルス幅変調
制御インバータ回路と、そのインバータ回路に供給する
直流電源に直列に接続された電流検出用抵抗と、その電
流検出用抵抗と並列接続した抵抗とホトカプラの発光側
の直列回路と、前記ホトカプラの受光側に直列に接続し
た出力電流を分流する可変可能な分流回路とサイリスタ
のゲート回路の並列回路と、前記サイリスタの出力によ
り前記スイッチング素子をオフする手段とからなること
を特徴とする過電流保護回路。
(1) Consisting of six switching elements, a pulse width modulation control inverter circuit, a current detection resistor connected in series with the DC power supply supplied to the inverter circuit, and a resistor connected in parallel with the current detection resistor. A series circuit on the light emitting side of the photocoupler, a parallel circuit consisting of a variable shunt circuit that shunts the output current connected in series to the light receiving side of the photocoupler, and a gate circuit of a thyristor, and the switching element is turned off by the output of the thyristor. An overcurrent protection circuit comprising means.
(2)4個のスイッチング素子よりなり、パルス幅変調
制御するブリッジ回路を用いたことを特徴とする特許請
求の範囲第(1)項記載の過電流保護回路。
(2) The overcurrent protection circuit according to claim (1), characterized in that a bridge circuit comprising four switching elements and performing pulse width modulation control is used.
JP59139092A 1984-07-06 1984-07-06 Overcurrent protecting circuit Pending JPS6122762A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59139092A JPS6122762A (en) 1984-07-06 1984-07-06 Overcurrent protecting circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59139092A JPS6122762A (en) 1984-07-06 1984-07-06 Overcurrent protecting circuit

Publications (1)

Publication Number Publication Date
JPS6122762A true JPS6122762A (en) 1986-01-31

Family

ID=15237301

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59139092A Pending JPS6122762A (en) 1984-07-06 1984-07-06 Overcurrent protecting circuit

Country Status (1)

Country Link
JP (1) JPS6122762A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH037015A (en) * 1989-06-02 1991-01-14 Fuji Electric Co Ltd Power ic
CN102377326A (en) * 2010-08-20 2012-03-14 深圳市澳地特电气技术有限公司 Insulated gate bipolar transistor (IGBT)-bridge-switch-topology-based driving circuit and protection module thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH037015A (en) * 1989-06-02 1991-01-14 Fuji Electric Co Ltd Power ic
CN102377326A (en) * 2010-08-20 2012-03-14 深圳市澳地特电气技术有限公司 Insulated gate bipolar transistor (IGBT)-bridge-switch-topology-based driving circuit and protection module thereof

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