Abstract: A process for manufacturing a composite polymeric circuit protection device in which a polymeric assembly is provided and is then subdivided into individual devices (2). The assembly is made by providing first and second laminates (7,8), each of which includes a laminar polymer element having at least one conductive surface, providing a pattern on at least one of the conductive surfaces on one laminate, securing the laminates in a stack (1) in a desired configuration, at least one conductive surface of at least one of the laminates forming an external conductive surface (3) of the stack, and making a plurality of electrical connections (31,51) between a conductive surface of the first laminate and a conductive surface of the second laminate. The laminar polymer elements may be PTC conductive polymer compositions, so that the individual devices made by the process exhibit PTC behavior. Additional electrical components may be attached directly to the surface of the device or assembly.

Abstract: A protection circuit for use with a charger and a chargeable element, such as a rechargeable lithium ion battery, comprises a shunt regulator having a threshold ON voltage coupled in parallel across the chargeable element, and a temperature-dependent resistor, e.g., a positive temperature coefficient device, coupled in series between the charger and the chargeable element. The temperature dependent resistor is thermally and electrically coupled to the shunt regulator, wherein the first variable resistor limits current flowing through the shunt regulator if the current reaches a predetermined level less than that which would cause failure of the regulator, due to ohmic heating of the regulator.

Abstract: An integrated system concurrently connects voice and data communications devices used by small and medium sized businesses to a network T1 data line terminating at the customer premises. A system chassis includes multiple slots and backplane connectors for removably receiving a bank controller unit (BCU), power service unit (PSU), and one or more different types of smart and dumb voice and data access modules that provide the functional interface to the customer premises equipment. The BCU controls the operation of the system, which can be configured by the customer through an external terminal interface.

Abstract: A software-based automated DS0 channel format analysis routine resident in a U-BRITE interface card's microcontroller solves the problem of potential misconfiguration of ISDN interface circuit cards, as may result from the failure to properly set DS0 time slot option switches to their intended ISDN channel assignments. When exercised, the routine automatically determines not only what DS0 channels are available at the remote ISDN circuit card, but also the order in which those DS0 channels are multiplexed by that remote card's circuitry. As a consequence, once the routine has run to completion, each ISDN interface card will contain the same DS0 time slot multiplexing scheme—corresponding to what has been manually configured at a remote card—even if the remote card's DS0 option switches were originally incorrectly set.

Abstract: A protection circuit for use with a charger and a chargeable element, such as a rechargeable lithium ion battery, comprises a shunt regulator having a threshold ON voltage coupled in parallel across the chargeable element, and a temperature-dependent resistor, e.g., a positive temperature coefficient device, coupled in series between the charger and the chargeable element. The temperature dependent resistor is thermally and electrically coupled to the shunt regulator, wherein the first variable resistor limits current flowing through the shunt regulator if the current reaches a predetermined level less than that which would cause failure of the regulator, due to ohmic heating of the regulator.

Abstract: A generally rectangular, planar electrical overcurrent sensing device having a top major surface and a bottom major surface includes a patterned metal foil conductor defined along the top major surface. The metal foil conductor has a first electrode region at one end region, a second electrode region at an opposite end region, and a current-concentrating region extending between the first electrode portion and the second electrode portion. The device further includes a planar sheet of a composition which exhibits PTC behavior and which comprises an organic polymer having a particulate conductive filler dispersed therewithin. The planar sheet has a first major surface in thermal contact with the bridging portion and has an opposite second major surface.

Abstract: Electrical devices, particularly circuit protection devices, contain conductive polymer elements whose edges are formed by breaking the conductive polymer element, along a desired path, without the introduction of any solid body into the element. The resulting cohesive failure of the conductive polymer produces a distinctive fractured surface. One method of preparing such devices involves etching fracture channels in the electrodes of a plaque containing a PTC conductive polymer element sandwiched between metal foil electrodes, and then snapping the plaque along the fracture channels to form individual devices.

Abstract: A laminar sensor for detecting changes on a laminar substrate. The sensor includes a laminar sheet which has a first surface and a second opposite surface, and is made from a conductive polymer composition which exhibits PTC behavior. A plurality of sensing elements are electrically connected in series on the sensor. Each sensing element is formed as an electrode pair containing a first electrode and a second electrode. The first and second electrodes may be on the same surface of the laminar sheet or on opposite surfaces of the sheet. Two electrical leads are present for connecting the sensing elements into a circuit, which may be used to detect changes in resistance which occur when a sensing element is exposed to an elevated temperature, a change in pressure, or a solvent.

Abstract: An electrical device in which a resistive element composed of a conductive polymer composition and two electrodes is made by a method in which the device is cut from a laminate of the conductive polymer composition and the electrodes, is exposed to a thermal treatment at a temperature above the melting temperature of the conductive polymer composition, and is then crosslinked.

Abstract: A reduced cost and hardware complexity ISDN channel bank architecture supports a plurality of Basic Rate-One Transmission Extension (BRITE) ISDN circuit cards. Rather than install a dedicated processor on each BRITE card or multiple BRITE circuits on one card, each BRITE circuit card of the channel bank has no processor of its own, but is instead controlled by a shared control processor on a separate bank controller card. Since each such `processorless` BRITE circuit card contains only single BRITE circuit, removal of any one BRITE circuit card from its backplane slot will not impair the operational integrity of the other BRITE cards, so that service to customer premises equipment terminating the local loops to such cards is not interrupted. The shared processor on the bank controller card executes the same single task communication control routine for plural BRITE cards.

Abstract: A conductive polymer composition which has a resistivity at 20.degree. C. of at most 1.0 ohm-cm and a PTC anomaly of at least 104 contains at most 64% by volume of a crystalline polymeric component and at least 36% by volume of a particulate conductive filler. A preferred conductive filler is carbon black having a DBP number of 60 to 120 cm.sup.3 /100 g. Compositions of the invention, as well as other conductive polymer compositions are preferably prepared by a method in which the polymeric component and the filler are blended in a first step at a temperature greater than the melting temperature of the polymer, the mixture is then cooled, and the mixture is then mixed in a second step. The resulting composition has a PTC anomaly that is at least 1.2 times the PTC anomaly of the first mixture.

Abstract: Electrical devices, particularly circuit protection devices, contain conductive polymer elements whose edges are formed by breaking the conductive polymer element, along a desired path, without the introduction of any solid body into the element. The resulting cohesive failure of the conductive polymer produces a distinctive fractured surface. One method of preparing such devices involves etching fracture channels in the electrodes of a plaque containing a PTC conductive polymer element sandwiched between metal foil electrodes, and then snapping the plaque along the fracture channels to form individual devices.

Abstract: A database of reversion cure constants is provided by measuring a physical property of a rubber formulation at two different temperatures as a function of time, calculating a set of cure constants for the rubber formulation which account for reversion, and storing the constants for later use either to optimize cure for a given process or of a given compound, or to assure quality of a raw compound. The invention also provides a curing press for optimizing cure including a mold, a heater, a temperature transducer, a computer and the database.

Abstract: An overhead bit-usurping multiplexing/demultiplexing mechanism increases the overall effective ISDN channel-conveying capacity of a serial digital data communication link, and thereby enables a terminal site channel bank to provide ISDN service to an additional number of customer premises equipments, other than the eight DSL channels normally accommodated within the twenty-four time slots of a (T1) TDM frame. Each condensed TDM DSL channel contains first and second multibit B information signal time slots, a multibit D information signal time slot, and a maintenance bit. No other auxiliary bits of a standard TR-NWT-000397 mode D+ octet are included, so that the compressed content TDM DSL channels have a smaller number of bits per channel than the standard TR-NWT-000397 format. As a result, when controllably interleaved with one another, the total number of TDM DSL channels (e.g.

Abstract: A conductive polymer composition which has a resistivity at 20.degree. C. of at most 1.0 ohm-cm and a PTC anomaly of at least 10.sup.4 contains at most 64% by volume of a crystalline polymeric component and at least 36% by volume of a particulate conductive filler. A preferred conductive filler is carbon black having a DBP number of 60 to 120 cm.sup.3 /100 g. Compositions of the invention, as well as other conductive polymer compositions are preferably prepared by a method in which the polymeric component and the filler are blended in a first step at a temperature greater than the melting temperature of the polymer, the mixture is then cooled, and the mixture is then mixed in a second step. The resulting composition has a PTC anomaly that is at least 1.2 times the PTC anomaly of the first mixture.

Abstract: A database of reversion cure constants is provided by measuring a physical property of a rubber formulation at two different temperatures as a function of time, calculating a set of cure constants for the rubber formulation which account for reversion, and storing the constants for later use either to optimize cure for a given process or of a given compound, or to assure quality of a raw compound. The invention also provides a curing press for optimizing cure including a mold, a heater, a temperature transducer, a computer and the database.