FR2475815A1 - Over-voltage protection circuit for power transistor - has zener diode passing extra current through current regulator to causes blockage of transistor - Google Patents
Over-voltage protection circuit for power transistor - has zener diode passing extra current through current regulator to causes blockage of transistor Download PDFInfo
- Publication number
- FR2475815A1 FR2475815A1 FR8003021A FR8003021A FR2475815A1 FR 2475815 A1 FR2475815 A1 FR 2475815A1 FR 8003021 A FR8003021 A FR 8003021A FR 8003021 A FR8003021 A FR 8003021A FR 2475815 A1 FR2475815 A1 FR 2475815A1
- Authority
- FR
- France
- Prior art keywords
- transistor
- current
- circuit
- zener
- protection circuit
- 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
Links
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
- H03K17/082—Modifications for protecting switching circuit against overcurrent or overvoltage by feedback from the output to the control circuit
- H03K17/0826—Modifications for protecting switching circuit against overcurrent or overvoltage by feedback from the output to the control circuit in bipolar transistor switches
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
Abstract
Description
Circuit de protection d'un transistor de puissance contre les stlrtensionc d'alimentation de longue durée
La présente invention due à la collaboration de M. SUQUET est relative à un circuit de protection d'un transistor de puissance contre les surtensions d'alimentation de longue durée.Circuit for protecting a power transistor against long-term supply voltage
The present invention due to the collaboration of M. SUQUET relates to a circuit for protecting a power transistor against long-term supply overvoltages.
I1 est courant, dans les circuits électroniques alimentés par une batterie B chargée par un générateur G, d'utiliser pour se protéger des surtensions d'alimentation causées par une déconnexion de la batterie, un circuit écrêteur connecté en parallele sur l'alimentation des circuits électroniques. Cet écretage peut être effectué par une diode zener de forte puissance. I1 is common, in electronic circuits supplied by a battery B charged by a generator G, to use to protect themselves from supply overvoltages caused by a disconnection of the battery, a clipping circuit connected in parallel on the circuit supply electronic. This clipping can be performed by a high power zener diode.
I1 est aussi pratique courante de limiter le courant des transistors de commande afin de se protéger d'un court-circuit de la charge ou de commander des charges à faible impédanc-. It is also common practice to limit the current of the control transistors in order to protect themselves from a short circuit of the load or to control loads with low impedance.
Cette limitation peut etre effectuée, par exemple, à partir de la mesure du courant circulant dans le transistor avec une résistance R située entre son émetteur et la masse.This limitation can be carried out, for example, from the measurement of the current flowing in the transistor with a resistor R located between its emitter and the ground.
Lors d'une surcharge comme celle provoquee par une déconnexion accidentelle de la batterie B en cours de charge par le générateur G, le transistor peut etre en conduction et dissiper une puissance excessive pendant la surcharge. Une telle situation risque de détériorer définitivement le transistor.During an overload like that caused by an accidental disconnection of the battery B during charging by the generator G, the transistor can be in conduction and dissipate an excessive power during the overload. Such a situation risks permanently damaging the transistor.
La présente invention permet de se prémunir contre un tel inconvénient.The present invention makes it possible to guard against such a drawback.
Suivant la présente invention, le circuit de protection d'un transistor de puissance contre les surtensions d'alimentation de longue durée qui est du type comportant un circuit écreteur connecté en parallèle sur l'alimentation des circuits électroniques associés au transistor, un circuit de régulation de courant dans le transistor et un élément de mesure du courant du transistor de puissance, est remarquable en ce que ledit transistor, le circuit écreteur et l'élément de mesure sont agencés de telle manière que le courant de dérivation du circuit écrêteur s'ecoule ensuite dans ltélément de mesure.According to the present invention, the circuit for protecting a power transistor against long-term supply overvoltages which is of the type comprising a clipping circuit connected in parallel to the power supply of the electronic circuits associated with the transistor, a regulation circuit. of current in the transistor and an element for measuring the current of the power transistor, is remarkable in that said transistor, the clipping circuit and the measuring element are arranged in such a way that the bypass current of the clipping circuit flows then in the measuring element.
Suivant un mode de réalisation préféré, un condensateur de filtrage est connecté en parallèle sur l'entrée du circuit écrêteur. According to a preferred embodiment, a filtering capacitor is connected in parallel to the input of the clipping circuit.
D'autres caractéristiquess ressortiront de la description qui suit et qui n'est donnée qu'a titre d'exemple. A cet effet, on se reportera au dessin joint iIlustrant a titre d'exemple un mode de réalisation non limitatif du circuit de protection suivant l'invention.Other characteristics will emerge from the description which follows and which is given only by way of example. To this end, reference will be made to the accompanying drawing, illustrating by way of example a non-limiting embodiment of the protection circuit according to the invention.
Suivant la représentation illustrée à la figure jointe, un transistor de puissance 10 est relie par son collecteur a un conducteur 12 transmettant la tension d'alimentation + V par l'intermédiaire d'un circuit de charge 11. L'émetteur du transistor 10 est relié, d'une part, à la masse par l'intermédiaire d'une résistance 16 de mesure du courant traversant le transistor, d'autre part, a partir d'un point 18 en entrée à un circuit 17 de regulation de courant connecté par sa sortie a un conducteur 19 relié a la base du transistor I0. According to the representation illustrated in the attached figure, a power transistor 10 is connected by its collector to a conductor 12 transmitting the supply voltage + V via a load circuit 11. The emitter of the transistor 10 is connected, on the one hand, to ground via a resistor 16 for measuring the current passing through the transistor, on the other hand, from a point 18 at the input to a connected current regulation circuit 17 by its output to a conductor 19 connected to the base of transistor I0.
Le transistor 10 reçoit par ailleurs sur sa base par l'intermédiaire du conducteur 19 des signaux sortant d'un circuit électronique de traitements qui n'a pas été représenté et dont il ntest pas néces- saire de préciser les caractéristiques car il ne fait pas partie de l'invention.The transistor 10 also receives on its base via the conductor 19 signals coming from an electronic processing circuit which has not been shown and whose characteristics it is not necessary to specify because it does not part of the invention.
Suivant l'invention, le point 18 de l'émetteur du transistor 10 est relié au conducteur 12 véhiculant la tension d'alimentation + V par l'intermédiaire de la connexion en série d'une diode zener de puissance 14 et d'une résistance de charge 13. Par ailleurs, le point 20 commun a la zener 14 et a la résistance 13 est mis à la masse par l'intermédiaire d'un condensateur de filtrage 15. Un moyen simple et économique pour améliorer la protection du transistor de commande 10 est donc de faire passer le courant circulant dans la zener 14 dans la résistance de mesure 16 du courant du transistor 10.According to the invention, point 18 of the emitter of transistor 10 is connected to conductor 12 conveying the supply voltage + V via the series connection of a power zener diode 14 and a resistor load 13. Furthermore, the point 20 common to the zener 14 and to the resistor 13 is grounded via a filtering capacitor 15. A simple and economical means for improving the protection of the control transistor 10 is therefore to pass the current flowing in the zener 14 into the measurement resistance 16 of the current of the transistor 10.
En fonctionnement normal, la diode zener 14 est bloquée et la régulation 17 de courant fonctionne sans perturbation. In normal operation, the zener diode 14 is blocked and the current regulation 17 operates without disturbance.
Pendant une surtension courte, le condensateur 15 filtre la surtension et la zener 14 reste bloquée. Le transistor supporte la surtension sans danger parce qu'elle est courte. Pendant une surtension de longue durée, la zener 14 entre en conduction et bloque le transistor par l'intermédiaire de la régulation de courant 17. En effet, le circuit de régulation détectant un courant plus fort réduit le courant du transistor jusqu' le bloquer si le courant zener est supérieur à celui du transistor.During a short overvoltage, the capacitor 15 filters the overvoltage and the zener 14 remains blocked. The transistor supports surge safely because it is short. During a long-term overvoltage, the zener 14 enters into conduction and blocks the transistor by means of current regulation 17. In fact, the regulation circuit detecting a stronger current reduces the current of the transistor until blocking it if the zener current is greater than that of the transistor.
Le circuit de protection suivant l'invention est économique car il est réalisé sans introduction de conposant supplementaire mais par une répartition nouvelle à l'intérieur du circuit des composants préexistants. La protection suivant l'invention permet, en réduisant l'énergie dissipée dans le transistor à chaque surtension, de choisir un transistor plus petit et moins coûteux ou de réduire son radiateur ou d'accroître sa fiabilité. The protection circuit according to the invention is economical because it is produced without the introduction of an additional component but by a new distribution within the circuit of the pre-existing components. The protection according to the invention makes it possible, by reducing the energy dissipated in the transistor at each overvoltage, to choose a smaller and less expensive transistor or to reduce its radiator or to increase its reliability.
Claims (4)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR8003021A FR2475815A1 (en) | 1980-02-12 | 1980-02-12 | Over-voltage protection circuit for power transistor - has zener diode passing extra current through current regulator to causes blockage of transistor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR8003021A FR2475815A1 (en) | 1980-02-12 | 1980-02-12 | Over-voltage protection circuit for power transistor - has zener diode passing extra current through current regulator to causes blockage of transistor |
Publications (2)
Publication Number | Publication Date |
---|---|
FR2475815A1 true FR2475815A1 (en) | 1981-08-14 |
FR2475815B3 FR2475815B3 (en) | 1982-10-15 |
Family
ID=9238477
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
FR8003021A Granted FR2475815A1 (en) | 1980-02-12 | 1980-02-12 | Over-voltage protection circuit for power transistor - has zener diode passing extra current through current regulator to causes blockage of transistor |
Country Status (1)
Country | Link |
---|---|
FR (1) | FR2475815A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2760489A1 (en) * | 1997-03-10 | 1998-09-11 | Siemens Ag | DEVICE AND METHOD FOR CONTROLLING AT LEAST ONE CAPACITIVE ADJUSTING MEMBER, IN PARTICULAR FOR AN INJECTION VALVE |
-
1980
- 1980-02-12 FR FR8003021A patent/FR2475815A1/en active Granted
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2760489A1 (en) * | 1997-03-10 | 1998-09-11 | Siemens Ag | DEVICE AND METHOD FOR CONTROLLING AT LEAST ONE CAPACITIVE ADJUSTING MEMBER, IN PARTICULAR FOR AN INJECTION VALVE |
Also Published As
Publication number | Publication date |
---|---|
FR2475815B3 (en) | 1982-10-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
FR2583590A1 (en) | DEVICE FOR PROTECTING AN ELECTRIC POWER LINE AGAINST HIGH TRANSIENT OVERVOLTAGES | |
US5808849A (en) | Method for the protection in particular of telecommunication installations and protection circuit for carrying out the method | |
EP1792378A1 (en) | Overvoltage protection device with improved leakage-current-interrupting capacity | |
EP1886393A2 (en) | Overvoltage protection and electronic circuit comprising such a device | |
FR2521791A1 (en) | ELECTRONIC CURRENT SWITCH MOUNTED IN A CONTINUOUS CURRENT DISTRIBUTION SYSTEM | |
US5333105A (en) | Transient voltage protector | |
EP0677907B1 (en) | Overcurrent protection device | |
FR2777134A1 (en) | HIGH INTENSITY PROTECTION CIRCUIT FOR TELEPHONE INTERFACE | |
FR2572600A1 (en) | ELECTRONIC VOLTAGE STABILIZER, PARTICULARLY FOR AUTOMOBILE USE, WITH PROTECTION AGAINST TRANSIENT OVERVOLTAGES OF POLARITY OPPOSITE TO THAT OF THE GENERATOR | |
FR2465894A1 (en) | ELECTRONIC DEVICE FOR CONTROLLING AN IGNITION COIL FOR AN INTERNAL COMBUSTION ENGINE | |
KR20200009421A (en) | Overvoltage protection circuit in vehicle | |
FR2475815A1 (en) | Over-voltage protection circuit for power transistor - has zener diode passing extra current through current regulator to causes blockage of transistor | |
FR2459568A1 (en) | CONTROL CIRCUIT OF A NETWORK | |
EP0373676A2 (en) | Protection apparatus against electrical overvoltages | |
EP0742631A2 (en) | Filtering device | |
EP3537551A1 (en) | Circuit for protection against voltage surges and electrical appliance comprising at least one such protection circuit | |
EP0116482B1 (en) | Voltage regulator with phase voltage holding and excitation short circuit protection for alternator | |
EP0738037B1 (en) | Excitation circuit for an alternator especially for motor vehicles and controller with an alternator containing it | |
CA1065959A (en) | Ground wire fed incandescent buoys | |
EP0055661B1 (en) | Control device for the regulation means in an electric ac-dc high-power converter | |
CH643693A5 (en) | Device for compensation of electric power network in reactive | |
FR1317824A (en) | ||
FR2790341A1 (en) | ALTERNATOR HAVING IMPROVED MEANS OF PROTECTION AGAINST LOAD LOADING, AND RELATED REGULATOR DEVICE | |
EP3970253A1 (en) | Autonomous security device and electric system comprising such a device | |
FR2716044A1 (en) | Protection of electronic equipment on T-T systems |