Abstract: A method for repairing a fuel cell stack having a plurality of individual cells involves the steps of: a) identifying at least one degraded individual cell in the fuel cell stack; and b) deactivating the at least one degraded individual cell.

Abstract: A liquid matrix of a nonmagnetic material is accommodated within an insulative container of a nonmagnetic material, and a pair of electrodes is disposed within the insulative container such that the electrodes face each other via the liquid matrix. Conductive particles are fluidly dispersed in the liquid matrix. A magnetic field generation section is provided externally of the insulative container so as to generate a magnetic field in a direction orthogonal to a fuse element to be formed between the paired electrodes through chaining of the solid particles.

Abstract: A microfluidic bubble fuse is formed from a hermetically sealed reservoir containing an electrically conductive liquid. The reservoir is interposed between a pair of electrodes such that each electrode is in electrical contact with the fluid within the reservoir, and such that the fluid within the reservoir provides electrical interconnectivity between the electrodes. The reservoir may be implemented on a substrate, in a tube, or in another manner. When the current or voltage across the electrodes increases beyond a threshold, the excess current or voltage will cause a bubble to be created within the fluid to reduce or inhibit the flow of electricity between the electrodes. When the current/voltage is reduced, the bubble will collapse to restore the flow of electricity between the electrodes.

Abstract: A liquid matrix of a nonmagnetic material is accommodated within an insulative container of a nonmagnetic material, and a pair of electrodes is disposed within the insulative container such that the electrodes face each other via the liquid matrix. Conductive particles are fluidly dispersed in the liquid matrix. A magnetic field generation section is provided externally of the insulative container so as to generate a magnetic field in a direction orthogonal to a fuse element to be formed between the paired electrodes through chaining of the solid particles.

Abstract: A microfluidic bubble fuse is formed from a hermetically sealed reservoir containing an electrically conductive liquid. The reservoir is interposed between a pair of electrodes such that each electrode is in electrical contact with the fluid within the reservoir, and such that the fluid within the reservoir provides electrical interconnectivity between the electrodes. The reservoir may be implemented on a substrate, in a tube, or in another manner. When the current or voltage across the electrodes increases beyond a threshold, the excess current or voltage will cause a bubble to be created within the fluid to reduce or inhibit the flow of electricity between the electrodes. When the current/voltage is reduced, the bubble will collapse to restore the flow of electricity between the electrodes.

Abstract: In accordance with the invention, there are thermal switches, method of operating thermal switches and methods of forming thermal switches. A thermal switch can include a thin layer of liquid crystal disposed between a first surface of a first insulating substrate and a second surface of a second insulating substrate, wherein the liquid crystals are aligned at one or more of the first surface and the second surface due to surface preparation.

Abstract: A self-recovering current-limiting device with a liquid metal includes a first and a second electrode for connection to an electric circuit to be protected. Each of the first and second electrodes are made of a solid metal. A plurality of pressure-resistant insulating bodies is provided, as well as a plurality of insulating intermediate walls supported by the insulating bodies. The plurality of insulating intermediate walls and the plurality of pressure-resistant insulating bodies define a plurality of compression spaces, and the plurality of insulating intermediate walls define a plurality of connecting channels. The plurality of compression spaces are disposed one behind the other between the first and second electrodes and are at least partially filled with the liquid metal.

Abstract: The switch device comprises a pair of cavities, an elongate passage, a non-conductive fluid having a high electrical resistance, a conductive fluid having a high electrical conductivity and an electrical path. The passage is in fluid communication with the cavities and has a substantially elliptical cross-section over at least part of its length. The non-conductive fluid is disposed in each of the cavities. The conductive fluid is located in the passage. The electrical path is changeable between a connected state and a disconnected state by the non-conductive fluid separating the conductive fluid in the passage into non-contiguous conductive fluid portions.

Abstract: A self-recovering device current limiting device with liquid metal includes two solid metal electrodes for connecting to an electric circuit to be protected. Several compression chambers partially filled with liquid metal are arranged one after the other between the electrodes. The compression chambers are formed by pressure-resistant insulating bodies and insulating intermediate walls supported by the insulating bodies. The insulating bodies include several connecting channels. To adjust the current limiting device to a desired nominal current factor, the level of the liquid metal above the connecting channels can be modified using an adjusting device. A reservoir is connected to the adjusting device, which can be adjusted and fixed in place externally.

Abstract: A self-recovering current-limiting device with a liquid metal includes two T-shaped electrodes for connection to an electric circuit to be protected. Each of the electrodes are made of a solid metal. Several compressor cavities which are partially filled with the liquid metal are situated one behind the other between the electrodes. The compressor cavities are formed by pressure-proof insulating bodies and by insulating intermediate walls which are provided with connecting channels and which are held by the insulating bodies. The insulating bodies and the intermediate walls form a uniform upper and lower half shell with opposite-lying joining surfaces. The half shells are connected in a sealed manner along joining surfaces in the area of a common middle plane of the connecting channels. Up to half of each of the electrodes is accommodated in corresponding recesses of the half shells, the electrodes extending with their respective middle limb out of the half shells.

Abstract: A self-recovering current-limiting device having liquid metal includes solid metal electrodes for connecting to an external electric circuit to be protected. A plurality of compression spaces which are partially filled with liquid metal are arranged one behind the other between the electrodes and are formed by pressure-resistant insulating bodies and by insulating partitioning walls having connecting channels. An enclosing insulating shaped housing is provided having a trough-like bottom part and a cover that tightly closes the bottom part via a non-positive and/or positive connecting device. The partitioning walls and the bottom part are interconnected as one piece. The connecting channels are configured as longitudinal holes which are open at the top. The electrodes are mounted in the bottom part. The nominal current range of the device may be easily adjusted.

Abstract: A self-regenerating current limiter with liquid metal includes solid metal electrodes for connection of the current limiter to an electric circuit to be protected. A plurality of compression chambers that are partially filled with liquid metal are located one behind the other between the electrodes. The compression chambers are formed by compression-proof insulating bodies and insulating partition walls that have communicating channels and that are supported by the insulating bodies. Non-conductive ceramic disks are mounted on the inner surfaces of the electrodes. The disks are located opposite the communicating channels of the adjacent partition walls.

Abstract: High voltage control devices are provided comprising a housing, an aprotic liquid contained within said housing, means for effecting heat exchange with said liquid, at least two spaced electrodes contained within said liquid and each of said electrodes extending from said housing. These devices find utility as variable resistors, circuit breakers, thermostats, optical triggering devices, acoustic pulse generators and the like.

Abstract: If one of a series string of battery cells fails on open circuit, the circuit through all of the cells is broken. An automatic means for by-passing the failed cell maintains the circuit and allows operation of the string to continue (at a lower no-lead voltage). The potential difference across the failed cell is utilized to heat a body of a conductive liquid so that it expands, ruptures the ampoule containing it and fills the gap between two conductors, thereby completing a shunt circuit.