| CPC H02H 3/16 (2013.01) [H02H 1/0015 (2013.01)] | 13 Claims |
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1. An electrical protection device comprising an input, an output, a control module and a switching module capable of channelling an electric current between the input and the output, the switching module comprising a first electrical circuit connecting the input to the output, the control module being configured to detect an electrical fault and to generate a first switching signal in the event of a fault being detected,
the first circuit comprising, connected in series between the input and the output, at least two head-to-tail normally-on JFET transistors and a switching member comprising a first terminal, a second terminal, a first actuator and a first contact, the first actuator being configured to move the first contact between a first position and a second position in response to the first switching signal, the first contact channelling the current between the first terminal and the second terminal when the first contact is in the first position, the first contact being spaced from at least one of the first and second terminals when the first contact is in the second position, the switching module being configured so that, upon a switchover of the first contact from the first to the second position when the current flows between the first terminal and the second terminal, an electric arc is formed between the first contact and the second terminal, and so that the appearance of the electric arc generates an electrical signal transmitted to at least one of the at least two head-to-tail normally-on JFET transistors, the electrical signal driving the switching of said at least one of the at least two head-to-tail normally-on JFET transistors,
the electrical protection device being capable of operating without auxiliary electrical power supply, by drawing some of the electrical energy from the electric arc that appears across the terminals of the switching member,
wherein each transistor of the at least two head-to-tail normally-on JFET transistors comprises a source, a drain and a gate, the electrical signal being a voltage between the gate and the source of each transistor of the at least two head-to-tail normally-on JFET transistors, the voltage being such that a conductive channel between the source and the drain of each transistor of the at least two head-to-tail normally-on JFET transistors is pinched under the effect of the voltage,
wherein the source of each transistor of the at least two head-to-tail normally-on JFET transistors is connected to a respective terminal from among the first terminal and the second terminal, the switching module comprises, for each transistor of the at least two head-to-tail normally-on JFET transistors, a second electrical circuit configured to electrically connect the gate of a transistor of the at least two head-to-tail normally-on JFET transistors under consideration to another terminal from among the first and the second terminal of the switching member so as to generate a voltage between the gate and the source of the transistor of the at least two head-to-tail normally-on JFET transistors under consideration in the event of an electric arc,
wherein each of the second electrical circuits comprises a first ohmic conductor and a diode having a cathode and an anode, the first ohmic conductor being connected in series between the cathode and the terminal to which each of the second electrical circuits is configured to connect the gate, the anode being connected to the gate of a corresponding transistor of the at least two head-to-tail normally-on JFET transistors,
wherein each of the second electrical circuits furthermore comprises a Zener diode and a second ohmic conductor that are connected in parallel between the gate and the source of a corresponding transistor of the at least two head-to-tail normally-on JFET transistors,
wherein in each of the second electrical circuits an anode of the Zener diode is connected to the gate of the corresponding transistor of the at least two head-to-tail normally-on JFET transistors.
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