Abstract: An explosion protected circuit board assembly that includes a circuit board having a carrier plate with conductive strips and at least one electrical component thereon. The circuit board assembly includes a housing part that defines a hollow space encasing the electronic component in intrinsically safe fashion while preventing flame transmission from the electrical component to the outside environment. In an alternative embodiment, housing parts defining hollow electrical component receiving spaces are mounted on opposite sides of the circuit board, with the components being electrically interconnected.

Abstract: A multi-position rotary switch comprises a plurality of identical switch chamber modules that are arranged one next to the other. Each switch chamber module holds a separate line switch allocated to a respective circuit. A standalone actuator housing holds a catch assembly for a switch shaft, which is coupled with a cam slide by means of a gear drive. The cam slide is located between a block like arrangement of switch chamber modules and the housing for the activation mechanism, which is designed for a standard configuration with three switch chamber modules connected to each other. The electrical terminals of the multi-position rotary switch are located on a narrow sides of the individual switch chamber modules.

Abstract: A hermetically sealed and/or ignition protection housing is provided with heat bridges at discreet points. The heat bridges form mounting faces in the interior space of the housing and also on the outer side. Heat from the interior of the housing generated by an item on the interior mounting faces is dissipated outwardly at the corresponding points by means of the heat bridges.

Abstract: A hermetically sealed and/or ignition protection housing is provided with heat bridges at discreet points. The heat bridges form mounting faces in the interior space of the housing and also on the outer side. Heat from the interior of the housing generated by an item on the interior mounting faces is dissipated outwardly at the corresponding points by means of the heat bridges.

Abstract: A hand held configuration for coupling to a two wire process control loop for use in configuring and monitoring field units coupled to the two wire process control loop is provided which includes a power supply, and at least two power islands. The power islands are configured to electrically isolate electrical components in one power island from electrical components in another power island. Independent power connections are provided between each power island and the power supply.

Abstract: A circuit arrangement includes a current measuring or temperature measuring device, used for triggering a shunt device. Said shunt device produces a short-circuit, which directly leads to the blowing of a fuse. The arrangement is modular and allows the operation of several current measuring devices on a common shunt device. Said arrangement is specifically adapted to prevent a protection resistor from warming up to too high a surface temperature in the case of an error, because the current is flowing for too much time.

Abstract: An intrinsically safe field maintenance tool includes terminals selectably coupleable to a process communication loop having a process industry standard communication protocol. At least one media is configured to communicate in accordance with a process industry standard communication protocol. A battery pack connector is adapted to removably couple to an intrinsically safe removable battery pack and provide power to circuitry in intrinsically safe field maintenance tool. An intrinsically safe battery pack is also provided.

Abstract: In a plastic housing of the "Flameproof Enclosure" ignition protection type, one part of the housing is provided at the parting plane with a rib (31) and the other housing part is provided with a groove complementary thereto. The cross-sectional dimensions of the groove are larger than the cross-sectional dimensions of the rib (31). The gap-like space obtained thereby is filled with a coating which adheres integrally either to the rib (31) or to the walls (14, 15) of the groove (13). This gives rise, between the coating and the other part to which it does not adhere integrally, to a gap which meets the requirement placed on an "ex-gap" of a flameproof housing.

Abstract: In a metal housing of the "Flameproof Enclosure" ignition protection type, one part of the housing is provided at the parting plane with a rib and the other housing part is provided with a groove complementary thereto. The cross-sectional dimensions of the groove are larger than the cross-sectional dimensions of the rib. The gap-like space obtained thereby is filled with a coating which adheres integrally either to the rib or to the walls of the groove. This gives rise, between the coating and the other part to which it does not adhere integrally, to a gap which meets the requirement placed on an "ex-gap" of a flameproof housing.

Abstract: To protect an encapsulated fuse (9) within a wholly enclosed sealed safety barrier having a first voltage limiting circuit (10) and a current limiting circuit (15), an externally accessible high current interrupter (5), such as a fuse, positive temperature coefficient resistor (26) or circuit breaker (27) is connected in series with an input terminal, and further serially connected with a second voltage limiting circuit (6) connected downstream of the interrupter and across the safety barrier circuit, the second voltage limiting circuit having a voltage limiting response characteristic which is, preferably, the same as the first voltage limiting circuit within the barrier, and the interrupter having a response threshold which is at least as high, but may be higher than the fuse (9) encapsulated within the circuit.

Abstract: The barrier input and output each have two terminals. In at least one connection between the barrier input and the barrier output, there is an electronic in-line control element having a control input as well as, in series with the in-line control element, a current sensing element that emits an output voltage corresponding to the current. A control circuit having a control input controls the conductive state of the in-line control element and to this end receives the output voltage of the current sensing element. In accordance with the invention, to obtain a steeper limiting characteristic, the control voltage for the control circuit is the sum of at least part of the output voltage of the current sensing element and at least part of a voltage corresponding to the voltage drop in the in-line control element.

Abstract: A fuse element with an essentially prismatic or cylindrical casing contains two electrical contacts that are accessible from the outside, that are situated on at least one exterior side of the casing and are electrically connected with a fuse arrangement inside the casing. In the casing an encoding arrangement is provided in which the electrical tripping characteristics of the fuse arrangement are encoded. To ensure a sufficient encoding variety with miniaturized design versions, even at higher manufacturers' tolerances, the encoding arrangement is formed by at least one appendage that is laterally or radially protruding from the casing in relation to the longitudinal axis of the casing and in whose configuration the tripping characteristics of the fuse arrangement are encoded.