Abstract: Switchgear, in particular relays and/or contactors having a solenoid system with armature and yoke, a coil and an open- and/or closed-loop control device of the switchgear drive are described, wherein actual values of drive-specific parameters are detected by sensors. After a switching command, the open- and/or closed-loop control device does not affect an output quantity (e.g., coil current) until at least one predefined threshold value of the switching parameters (for example, of contact speed) is attained.

Abstract: A current-limiting switch, with current connections and contacts, at least one of which is movable, having an associated drive, for opening the moving contact when a predefined electric current intensity is exceeded, are provided. The drive is a thermoelectric drive where a disk-shaped resistor body is present, in a closed housing made of insulating material, for high-intensity discharges, plurality of resistor bodies and associated electrode disks, acting as contacts, are connected electrically in parallel and mechanically in series in the housing made of an insulating material (1). This results in increased switching capacity with compact design.

Abstract: Switching devices can have means for contactless switching position detection. According to the invention, magnetic field sensors arranged at suitable locations inside and/or outside a device housing are provided for switching position detection. In particular, position-dependent magnetic fields are measured for ON/OFF position detection, overcurrent triggering, and contact welding; however, the magnetic field of the current flowing is detected to recognize short-circuit triggering. Differential Hall effect sensors and Reed contacts, respectively, can be used for these purposes. In addition, a sound sensor can be provided for detecting the switching noise, whose signal is evaluated together with the overcurrent triggering signal for short-circuit detection.

Abstract: A current limiter with a controllable resistance which assumes a low value during rated service and a high value during a short-circuit disconnect. The current limiter includes a thermoplastic resistive member between two flat, metallic electrodes. Each of the flat metallic electrodes has a surface profile on the side facing the thermoplastic resistive member. The resistive member has a surface profile complementary to the surface profile on the adjacent surfaces of the flat electrodes. The flat electrodes and the resistive member are thereby inseparably connected, with the flat electrodes and the resistive member being pressed together by a pressure force. The interlocking of the surfaces results in an especially rapid readjustment of the limiter resistance from its high-resistance state during a short-circuit disconnect back to the low-resistance state during rated service.

Abstract: A single circuit-breaker is provided in the phase conductor, and the bridging circuit is provided on the load side of the single circuit-breaker, and a magnetically driven switching contact closes a bridging current branch leading to the neutral conductor. The bridging circuit conducts a part of the short-circuit current past the magnetic drive and/or the switching contact. A resistor whose resistance value amounts to between 25 and 50% of the value of the smallest load-circuit impedance (L.sub.2, R.sub.2) to be expected, may be provided in the bridging current branch. In such an arrangement, the bridging circuit and the circuit-breaker can form one unit.

Abstract: A variable high-current resistor, especially for use as a protective element in power switching technology has already been proposed, which contains carbon as a resistance material, at least one boundary layer with a transition zone to another electric conductor being provided. By applying a contact pressure, the resistance in the transition zone can be kept low. Under the prior art, the resistance is converted into a highly resistive state by means of Joulean heat. In accordance with the invention, the contact pressure of the variable high-current resistor is able to be selectively influenced, the carbon- and/or carbon-black-containing layer being pressed by the surface pressure with a preset first value against the other conductor to adjust the low-resistance state of the resistor, and that, in the event of a short-circuit, this contact pressure being able to be reduced in a short enough time to a second value, at which the resistance in the transition zone goes up by at least two orders of magnitude.

Abstract: A hybrid switch is provided for switching a sink on and off. The hybrid switch contains a first semiconductor switch with a commutation switch. According to the present invention, a magnetic drive includes a first magnetic coil through which short-circuit current flows. A second semiconductor switch is connected in series with a second magnetic coil that series being connected in parallel to the series connection of the first magnetic coil and the sink. Short circuit flows through the first magnetic coil via the commutation switch which bridges at least the first semiconductor switch.