JP3123261B2 - Glow plug controller - Google Patents
Glow plug controllerInfo
- Publication number
- JP3123261B2 JP3123261B2 JP04300526A JP30052692A JP3123261B2 JP 3123261 B2 JP3123261 B2 JP 3123261B2 JP 04300526 A JP04300526 A JP 04300526A JP 30052692 A JP30052692 A JP 30052692A JP 3123261 B2 JP3123261 B2 JP 3123261B2
- Authority
- JP
- Japan
- Prior art keywords
- glow plug
- storage battery
- power mosfet
- power
- voltage
- 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 - Fee Related
Links
Description
【０００１】[0001]
【産業上の利用分野】本発明は、主としてディーゼルエ
ンジンに用いられるグロープラグの制御装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a glow plug mainly used in a diesel engine.
【０００２】[0002]
【従来の技術】従来、グロープラグの通電制御にはリレ
ーが用いられており、半導体パワーMOSFETによる通電制
御は、利点の多いアイデアとしては知られているけれど
も実用化されていない。また通常、電装品は、蓄電池の
逆接続時に対する保護対策としてヒューズ回路が多く用
いられる。2. Description of the Related Art Hitherto, a relay has been used for energization control of a glow plug, and energization control by a semiconductor power MOSFET is known as an idea having many advantages, but has not been put to practical use. In general, a fuse circuit is often used for electrical components as a protection measure against reverse connection of a storage battery.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、グロー
プラグ制御装置では、パワーMOSFET自体が大電流スイッ
チであり、蓄電池とグロープラグとの間に直列に接続し
てあって、しかもパワーMOSFETはその構造上、寄生ダイ
オードが存在し、逆接続時にも回路が通電状態にある。
従って、何も対策を施さない場合、逆接続時にパワーMO
SFETは逆電流による発熱で短時間に破壊してしまうとい
う問題がある。そのため、パワーMOSFETは、きめ細かな
制御ができるという優位性を持ちつつも、安全性・経済
性の面からまだ実用化されていないのが実情である。However, in the glow plug control device, the power MOSFET itself is a large current switch, which is connected in series between the storage battery and the glow plug. , A parasitic diode exists, and the circuit is in a conductive state even in the reverse connection.
Therefore, if no countermeasures are taken, the power MO
The SFET has a problem that it is destroyed in a short time due to heat generated by a reverse current. For this reason, power MOSFETs have the advantage of being capable of fine-grained control, but have not yet been put to practical use in terms of safety and economy.
【０００４】また、通常の電装品と違い、パワーMOSFET
には逆接続時の逆電流と同程度の順電流が正常接続時に
流れるため、ヒューズ回路は使用できないという問題が
ある。そこで、通常の電気回路で逆電流を防ぐためのダ
イオードをパワーMOSFETに直列に追加することが考えら
れるが、大電流用のダイオードは現実に無く、あったと
しても高価である上、ダイオードの電圧降下が生じてグ
ロープラグへの電力が低下してしまうため使用できな
い。[0004] Unlike ordinary electrical components, power MOSFETs
Has a problem that a fuse circuit cannot be used because a forward current approximately equal to a reverse current at the time of reverse connection flows at the time of normal connection. Therefore, it is conceivable to add a diode for preventing reverse current in a normal electric circuit in series with the power MOSFET. It cannot be used because the power to the glow plug is reduced due to the drop.
【０００５】むしろ、蓄電池の逆接続状態は元々定常的
な状態ではなく、蓄電池を交換する際に発生するのがほ
とんどであり、蓄電池の端子を回路に接触した瞬間に電
流が流れ、放電等を起こして異常であることが判明す
る。しかし、その時点ではもう電装品に充分逆電圧が印
加されてしまっているので、この時点で破壊しないため
の対策は必要不可欠である。従って当発明の目的は、蓄
電池の逆接続状態において電流が流れてしまうのが防ぐ
ことができない代わりにパワーMOSFETが破壊してしまう
のを防ぐことにある。[0005] Rather, the reverse connection state of the storage battery is not a stationary state from the beginning, but almost always occurs when the storage battery is replaced. When the terminal of the storage battery contacts the circuit, a current flows and discharge occurs. Wake up and find out it is abnormal. However, at that point, a sufficient reverse voltage has already been applied to the electrical components, and measures to prevent breakdown at this point are indispensable. Accordingly, an object of the present invention is to prevent a current from flowing in a reverse connection state of a storage battery, but to prevent a power MOSFET from being destroyed.
【０００６】[0006]
【課題を解決するための手段】上記の問題を解決するた
めに、半導体パワーMOSFETによるグロープラグ通電制御
回路において、蓄電池が逆極性で接続された時にパワー
MOSFETをオンさせる電圧をゲートに印加する回路を接続
する。In order to solve the above problem, in a glow plug energization control circuit using a semiconductor power MOSFET, when a storage battery is connected with a reverse polarity, the power is reduced.
Connect a circuit that applies a voltage to turn on the MOSFET to the gate.
【０００７】[0007]
【作用】蓄電池の逆接続時には、アース側がプラスの電
圧になるので、上記の回路によりパワーMOSFETのゲート
に蓄電池の本来極性による電圧が印加されてパワーMOSF
ETは導通状態になる。When the storage battery is reversely connected, the ground side has a positive voltage. Therefore, the voltage according to the original polarity of the storage battery is applied to the gate of the power MOSFET by the above circuit, and the power MOSF is applied.
ET becomes conductive.
【０００８】[0008]
【発明の効果】蓄電池逆接続時にパワーMOSFETを通電状
態にするので、逆電流が寄生ダイオードを通らず素子内
の本来の電流回路を流れることになり、パワーMOSFETの
発熱が抑えられ、製品破壊を免れる。Since the power MOSFET is turned on when the storage battery is reversely connected, the reverse current flows through the original current circuit in the element without passing through the parasitic diode, thereby suppressing the heat generation of the power MOSFET and preventing product destruction. Escape.
【０００９】[0009]
【実施例】以下、本発明を実施例に基づいて説明する。
図１は、パワーMOSFETをスイッチング素子として用いた
グロープラグ制御装置の主要な回路図である。蓄電池１
は逆接続状態となっている。２ａ〜２ｄはグロープラ
グ、３は２個並列にした約５ｍΩのパワーＭＯＳＦＥＴ
で、３ａは素子の寄生ダイオードで動作電圧が約１Ｖで
ある。４が本発明を特徴づける回路で、この実施例では
パワーMOSFETがｎ−ｃｈタイプであるので、ダイオード
４がグロープラグのアース側からＦＥＴのゲート３ｇに
抵抗を介して接続してある。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
FIG. 1 is a main circuit diagram of a glow plug control device using a power MOSFET as a switching element. Storage battery 1
Is in a reverse connection state. 2a to 2d are glow plugs and 3 is a power MOSFET of about 5mΩ in parallel.
Numeral 3a denotes a parasitic diode of the element, whose operating voltage is about 1V. Reference numeral 4 denotes a circuit which characterizes the present invention. In this embodiment, since the power MOSFET is an n-ch type, the diode 4 is connected from the earth side of the glow plug to the gate 3g of the FET via a resistor.
【００１０】蓄電池１が正常な接続状態の場合は、制御
回路から出されるパワーMOSFET駆動信号を適切な電圧に
してパワーMOSFETのゲート３ｇに印加してパワーMOSFET
３を通電する。このときダイオード４は逆バイアスにな
るので電流は流れない。しかし、蓄電池１が逆接続状態
の時は、ダイオード４は逆極性の蓄電池１により順方向
にバイアスされるので通電状態となり、ゲート３ｇにバ
イアス電圧が印加され、パワーMOSFET３はターンオンす
る。パワーMOSFET３のソース、ドレインにはグロープラ
グを介して蓄電池１の電圧がかかり、寄生ダイオード３
ａを流れようとする。この電流が３０Ａとすると約３０
Ｗの電力がパワーMOSFET３に加わるが、本案では上記の
ダイオード４によってほぼ同時にパワーMOSFET３が導通
しているので寄生ダイオード３ａには電流が流れず、約
4.5 Ｗの電力がパワーMOSFET３に加わり、約８５％の電
力を減少することができ、熱破壊を防止できる。When the storage battery 1 is in a normal connection state, the power MOSFET drive signal output from the control circuit is set to an appropriate voltage and applied to the gate 3g of the power MOSFET to apply the power MOSFET drive signal.
3 is energized. At this time, no current flows because the diode 4 is reverse-biased. However, when the storage battery 1 is in the reverse connection state, the diode 4 is biased in the forward direction by the storage battery 1 having the opposite polarity, so that the diode 4 is energized, a bias voltage is applied to the gate 3g, and the power MOSFET 3 is turned on. The voltage of the storage battery 1 is applied to the source and drain of the power MOSFET 3 via the glow plug, and the parasitic diode 3
try to flow a. Assuming that this current is 30A, about 30
Although the power of W is applied to the power MOSFET 3, in the present invention, since the power MOSFET 3 is conducting at substantially the same time by the above-described diode 4, no current flows through the parasitic diode 3a.
4.5 W of power is applied to the power MOSFET 3 to reduce the power by about 85%, thereby preventing thermal destruction.
【００１１】また、図２に本発明の別の実施例を示す。
この例では、図１のダイオード４の代わりにｐ−ｃｈタ
イプのＦＥＴ２４が用いられている。そのＦＥＴ２４は
ソース２４ｓがアースに接続され、ドレイン２４ｄがパ
ワーMOSFET２３のゲート２３ｇに接続されている。ま
た、ゲート２４ｇはＦＥＴ２３のドレイン２３ｄに接続
されている。他は図１と同じ構成である。そして蓄電池
２１の極性が逆となり、ＦＥＴ２４のゲート２４ｇがア
ースに対して電源電圧分だけ低い電位になってＦＥＴ２
４がオンとなる。これにより、ＦＥＴ２３のゲート２３
ｇにはソース２３ｓより十分高い電圧が印加されるので
ＦＥＴ２３はターンオンする。このことで図１の実施例
と同様の効果を果たす。FIG. 2 shows another embodiment of the present invention.
In this example, a p-ch type FET 24 is used instead of the diode 4 in FIG. The FET 24 has a source 24 s connected to the ground and a drain 24 d connected to the gate 23 g of the power MOSFET 23. The gate 24g is connected to the drain 23d of the FET 23. The other configuration is the same as that of FIG. Then, the polarity of the storage battery 21 is reversed, and the gate 24g of the FET 24 becomes lower in potential than the ground by the power supply voltage, so that the FET 2
4 turns on. Thereby, the gate 23 of the FET 23
Since a voltage higher than the source 23s is applied to g, the FET 23 is turned on. This achieves the same effect as the embodiment of FIG.
【図１】本発明の実施例を示すグロープラグ制御回路
図。FIG. 1 is a glow plug control circuit diagram showing an embodiment of the present invention.
【図２】本発明の別の実施例を示すグロープラグ制御回
路図。FIG. 2 is a glow plug control circuit diagram showing another embodiment of the present invention.
１ 蓄電池（逆接状態） ２ａ〜２ｄ グロープラグ ３ パワーＭＯＳＦＥＴ ４ 逆接保護用ダイオード ２１ 蓄電池（逆接状態） ２２ａ〜２２ｄ グロープラグ ２３ パワーＭＯＳＦＥＴ ２４ ｐ−ｃｈ ＭＯＳＦＥＴ DESCRIPTION OF SYMBOLS 1 Storage battery (reverse connection state) 2a-2d glow plug 3 Power MOSFET 4 Reverse connection protection diode 21 Storage battery (reverse connection state) 22a-22d Glow plug 23 Power MOSFET 24 p-ch MOSFET
Claims (1)
の半導体パワーMOS型電界効果トランジスタ(MOSFET)を
直列接続してグロープラグの通電を制御する装置におい
て、前記蓄電池への接続が逆極性で行われた時に、その
逆極性の電圧により前記パワーMOSFETをオンさせる電圧
をゲートに印加させる保護回路を備えることを特徴とす
るグロープラグ制御装置。1. An apparatus for controlling the energization of a glow plug by connecting in series a semiconductor power MOS type field effect transistor (MOSFET) for energization control between the glow plug and a storage battery, wherein the connection to the storage battery is of opposite polarity. A glow plug control device comprising a protection circuit for applying a voltage for turning on the power MOSFET to a gate with a voltage having the opposite polarity when the above operation is performed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04300526A JP3123261B2 (en) | 1992-10-12 | 1992-10-12 | Glow plug controller |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04300526A JP3123261B2 (en) | 1992-10-12 | 1992-10-12 | Glow plug controller |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06129337A JPH06129337A (en) | 1994-05-10 |
| JP3123261B2 true JP3123261B2 (en) | 2001-01-09 |
Family
ID=17885885
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04300526A Expired - Fee Related JP3123261B2 (en) | 1992-10-12 | 1992-10-12 | Glow plug controller |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3123261B2 (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2737259B1 (en) * | 1995-07-27 | 1997-09-12 | Sagem | DIESEL ENGINE GLOW PLUG CONTROL CIRCUIT |
| US7288856B2 (en) | 2003-05-14 | 2007-10-30 | International Rectifier Corporation | Reverse battery protection circuit for power switch |
| US7463468B2 (en) | 2003-05-14 | 2008-12-09 | International Rectifier Corporation | Reverse circulation protection circuit |
| US7283343B2 (en) * | 2004-12-15 | 2007-10-16 | Texas Instruments Incorporated | Integrated reverse battery protection circuit for an external MOSFET switch |
| JP2007019812A (en) * | 2005-07-07 | 2007-01-25 | Yazaki Corp | Load driving device provided with reverse connection protection function for power source |
| EP2133554A4 (en) | 2007-03-05 | 2012-03-21 | Bosch Corp | Glow plug drive device |
| JP5266029B2 (en) * | 2007-12-14 | 2013-08-21 | ルネサスエレクトロニクス株式会社 | Load drive device |
| JP2009191642A (en) * | 2008-02-12 | 2009-08-27 | Autonetworks Technologies Ltd | Glow plug protection circuit |
| JP5407457B2 (en) * | 2009-03-18 | 2014-02-05 | 株式会社デンソー | Energization control device |
| JP5747727B2 (en) * | 2011-08-08 | 2015-07-15 | 株式会社デンソー | Power supply reverse connection protection device |
| JP5884694B2 (en) | 2012-09-20 | 2016-03-15 | 株式会社デンソー | Semiconductor device |
| JP6213136B2 (en) * | 2013-10-17 | 2017-10-18 | 富士電機株式会社 | Semiconductor device |
-
1992
- 1992-10-12 JP JP04300526A patent/JP3123261B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06129337A (en) | 1994-05-10 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |