Asea Brown Boveri Ab

Abb Ab

Hans Bernhoff

Jan Isberg

Pan Min

Peter Isberg

Mark Irwin

Mats Ekberg

&angst;ke &Ouml;berg

Anders Sunesson

Mats Leijon

Bertil Berggren

Stefan Valdemarsson

Lars Liljestrand

Lars E Jonsson

Erik Johansson

Henrik Breder

Li Ming

Dan Windmar

Per Skytt

Mikael Bergkvist

An electric coupling device for connecting, disconnecting or limiting the current in an electric circuit. The electric coupling device includes a variable resistor. This resistance is variable between a very low value corresponding to a conducting state and a very high value corresponding to a substantially insulating state. Switching between the states takes place continually and in a very short time. The invention relates to an electric circuit provided with such an electric coupling device and a method performed in accordance with the function of the electric coupling device.

Electric coupling device, electric circuit and method in connection therewith

A photoconductive switch comprises a first layer (,), two contact layers (,) arranged on said first layer and connectable to different potentials for applying a voltage thereacross, said first layer being adapted to be conducting upon applying a voltage across said contact layers when exposed to light from an illumination source of an energy high enough for lifting charge carriers from the valence band to the conduction band of the material of said first layer. The illumination source is an excimer lamp, in which unstable electronically excited dimers are formed when a voltage is applied across first and second electrodes (,) separated by a gas or gas mixture. The dimers so formed decompose into two gas atoms while emitting a photon of an energy suitable for lifting charge carriers from the valence band to the conduction band of the material of the first layer.

Photoconductive switch

An electric switching device comprises a quick mechanical electric switch and an irradiation source and at least one switching element sensitive to irradiation and adapted to create an electrically well conducting current path by-passing the electric mechanical switch upon irradiation thereon through the irradiation source, but assuming an electrically insulating state in absence of irradiation thereon. The quick mechanical electric switch is capable of being quickly de-ionized after extinction of an electric arc created therein upon separation of the contacts of the mechanical switch.

Electric switching device and a method for performing electric disconnection of a load

This invention is related to a device and a method in an electric power plant for protection of an object (,) against over-currents from a network (,) or another equipment included in the high voltage plant, the device comprising a switching device (,) in a line (,) between the object and the network/equipment. The line (,) between the object and the network/equipment is connected to an arrangement (,) reducing over-currents towards the object (,), said arrangement (,) being actuatable for over-current reduction with the assistance of an over-current condition detecting arrangement (,) within a time period substantially less than the break-time of the switching device (,).

Device and method relating to protection of an object against over-currents comprising over-current reduction

A device having two opposite terminals interconnected by material layers for switching between a current conducting state and a state blocking transport of charge carriers between the terminals upon applying a voltage there across has as the material layers a first layer made of intrinsic diamond and a second layer arranged next to the first layer. The device switches to the conducting state by providing free charge carriers in the second layer for transport through the diamond layer through the voltage and the blocking state by stopping providing the free charge carriers for the transport. The diamond layer is adapted to take a major part of the voltage across the terminals in the blocking state.

Switching device

A photoconductive switch comprises a first layer (,) of a first material sandwiches between two contact layers (,). The first layer is adapted to be conducting upon applying a voltage across said contact layers when irradiated by light (,) of an energy high enough for lifting charger carriers from the valence band to the conduction band of the first material. A first (,) of the contact layers is provided with apertures (,) for allowing light applied on the switch to reach said first layer there for making the switch conducting upon applying a voltage across the two contact layers. A thin second layer (,) is arranged on the side of the first contact layers, at least covering the surfaces of the first layer exposed through said apertures and forming an interface to said first layer in said apertures. The second layer is made of a material being able to form a well ordered interface to said first material and having the same or a larger band gap than the latter.

Photoconductive switch with multiple layers

To provide for fast switching at high powers while relieving stress on a mechanical switch, an electric switching device comprising a mechanical electric switch and an irradiation source and at least one switching element sensitive to irradiation is adapted to create an electrically well conducting current path by-passing the mechanical switch upon irradiation of the switching element by the irradiation source. The switching element assumes an electrically insulating state in the absence of irradiation thereof. The switching element includes rectifiers adapted to be reverse biased when not irradiated and conducting as a consequence of generation of free charge carriers therein through irradiation by the irradiation source.

Electric switching device and a method for performing electric

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Västerås, Sweden

Hans Bernhoff