JPH04207314A - Control circuit for switching element - Google Patents
Control circuit for switching elementInfo
- Publication number
- JPH04207314A JPH04207314A JP32917790A JP32917790A JPH04207314A JP H04207314 A JPH04207314 A JP H04207314A JP 32917790 A JP32917790 A JP 32917790A JP 32917790 A JP32917790 A JP 32917790A JP H04207314 A JPH04207314 A JP H04207314A
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- snubber capacitor
- control circuit
- switching element
- zener
- 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
- 239000003990 capacitor Substances 0.000 claims abstract description 17
- 238000001514 detection method Methods 0.000 claims abstract description 5
- 238000005516 engineering process Methods 0.000 description 2
- 230000006378 damage Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
Landscapes
- Electronic Switches (AREA)
- Thyristor Switches And Gates (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明はスナバ回路を有するスイッチング素子の動作制
御と保護に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the operation control and protection of switching elements having snubber circuits.
従来のスナバ回路を有するスイッチング素子の制御回路
は、OHM]、1月号別冊(1987年、株式会社オー
ム社刊行)の第123頁に述べられているように、最小
オン時間の確保をスナバ回路の状態とは無関係に一定の
時間としていたにのような制御方法は、必要以上に最小
オン時間を設定しなければならず、装置の高周波化を制
約することになる。Conventional switching element control circuits with snubber circuits use snubber circuits to ensure the minimum on-time, as stated in page 123 of OHM, January issue supplement (1987, published by Ohmsha Co., Ltd.). In a control method such as that in which the on-time is set to be a constant time regardless of the state of the on-state, the minimum on-time must be set longer than necessary, which limits the ability of the device to operate at higher frequencies.
また、誤動作等によりスナバコンデンサが十分放電して
いない状態でスイッチング素子にオフ信号が与えられる
ような場合、素子を保護しきれない。Furthermore, if an off signal is applied to the switching element while the snubber capacitor is not sufficiently discharged due to malfunction or the like, the element cannot be protected.
上記従来技術は、スナバコンデンサが十分放電するよう
に最小オン時間髪ある程度長くとらなければならず高周
波化への制約になるという問題があった。The above-mentioned conventional technology has a problem in that the minimum on-time must be long to some extent so that the snubber capacitor can be sufficiently discharged, which is a constraint on higher frequencies.
また、ノイズ等による誤パルスの発生によって最小オン
時間中にスイッチング素子がオフ動作し破壊することが
あるという問題があった。Furthermore, there is a problem in that the switching element may turn off during the minimum on-time due to the generation of erroneous pulses due to noise or the like, resulting in destruction.
本発明の目的は、最小オフ時間髪必要最小限に押さえる
ことにある。An object of the present invention is to suppress the minimum hair-off time to the necessary minimum.
本発明の他の目的は、最小オフ時間中にスイッチング素
子をオフ動作させないことにある。Another object of the present invention is to prevent the switching element from being turned off during the minimum off time.
上記目的を達成するために、スナバコンデンサの電圧を
検知し低電圧になるとすくにオフ信号を与えられるよう
にしたものである。In order to achieve the above object, the voltage of the snubber capacitor is detected and an off signal is immediately applied when the voltage becomes low.
さらに、スイッチング素子の保護のために高電圧のとき
にはオフ信号を与えないようにしたものである。Furthermore, in order to protect the switching elements, an off signal is not applied when the voltage is high.
検知回路は、スナバコンデンサが低電圧のとき制御回路
にオフ信号の出力を許可し、高電圧のときにはオフ信号
の出力を禁止する。The detection circuit allows the control circuit to output an off signal when the snubber capacitor has a low voltage, and prohibits output of the off signal when the snubber capacitor has a high voltage.
それによって、制御回路は検知回路からの許可がある場
合にオフ信号をスイッチング素子に与えることができ、
スナバコンデンサが高電圧の時に誤ったオフ信号を与え
ることがない。Thereby, the control circuit can provide an off signal to the switching element if given permission from the sensing circuit;
The snubber capacitor does not give a false off signal when the voltage is high.
以下、本発明の一実施例を第1図により説明する。 An embodiment of the present invention will be described below with reference to FIG.
スナバコンデンサ5の電圧を分圧抵抗器7、及び分圧抵
抗器8で適当な電圧に分圧し、検知電圧のレベルをツェ
ナーダイオード9によって決定する、信号は発光ダイオ
ード10、及び受光トランジスタ11により絶縁され制
御回路にフィードバックされる。The voltage of the snubber capacitor 5 is divided into appropriate voltages by a voltage dividing resistor 7 and a voltage dividing resistor 8, and the level of the detection voltage is determined by a Zener diode 9. The signal is isolated by a light emitting diode 10 and a light receiving transistor 11. and fed back to the control circuit.
今、分圧抵抗器8の両端電圧がツェナーダイオード9の
ツェナー電圧より高電圧の場合1発光ダイオード10に
電流が流れ受光トランジスタ11がオン状態に保たれる
。これにより、制御回路1がオフ動作出力を出しても駆
動回路2はオン動作のままとなっており、スナバコンデ
ンサ5の電圧がツェナーダイオード9のツェナー電圧よ
り低くなると駆動回路2にただちにオフ動作信号が与え
られる。Now, when the voltage across the voltage dividing resistor 8 is higher than the Zener voltage of the Zener diode 9, a current flows through one light emitting diode 10, and the light receiving transistor 11 is kept in an on state. As a result, even if the control circuit 1 outputs an OFF operation output, the drive circuit 2 remains in the ON operation, and when the voltage of the snubber capacitor 5 becomes lower than the Zener voltage of the Zener diode 9, an OFF operation signal is immediately sent to the drive circuit 2. is given.
これによって、スナバコンデンサ5の充電電圧が高い場
合はスイッチング素子3をオフ動作させることなく、最
小オン時間を限界まで短くすることができる。As a result, when the charging voltage of the snubber capacitor 5 is high, the minimum on-time can be shortened to the limit without turning off the switching element 3.
本発明によれば、最小オン時間を限界まで短くすること
ができるので装置をより高周波で動作することができる
。また、ノイズ等によりスナバコンデンサが高電圧のと
きにスイッチング素子をオフ動作させることも防止でき
る。According to the present invention, since the minimum on-time can be shortened to the limit, the device can be operated at a higher frequency. Further, it is also possible to prevent the switching element from turning off when the snubber capacitor is at a high voltage due to noise or the like.
第1図は本発明の一実施例の回路構成図を示す。
4・・・スナバダイオード、5・・・スナバコンデンサ
。
6・・・スナバ抵抗器、10・・・発光ダイオード、1
1・・・受光トランジスタ。
第 1 因FIG. 1 shows a circuit diagram of an embodiment of the present invention. 4... Snubber diode, 5... Snubber capacitor. 6... Snubber resistor, 10... Light emitting diode, 1
1... Light receiving transistor. First cause
Claims (1)
素子と並列に設けられた抵抗器とコンデンサを有するス
ナバ回路において、スナバコンデンサの電圧、もしくは
電流を検知して制御回路にフィードバックする検知回路
を設けたことを特徴とするスイッチング素子の制御回路
。1. In order to protect the switching element, in the snubber circuit that has a resistor and capacitor installed in parallel with the switching element, a detection circuit is installed to detect the voltage or current of the snubber capacitor and feed it back to the control circuit. A switching element control circuit characterized by:
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP32917790A JPH04207314A (en) | 1990-11-30 | 1990-11-30 | Control circuit for switching element |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP32917790A JPH04207314A (en) | 1990-11-30 | 1990-11-30 | Control circuit for switching element |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH04207314A true JPH04207314A (en) | 1992-07-29 |
Family
ID=18218512
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP32917790A Pending JPH04207314A (en) | 1990-11-30 | 1990-11-30 | Control circuit for switching element |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH04207314A (en) |
-
1990
- 1990-11-30 JP JP32917790A patent/JPH04207314A/en active Pending
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