Abstract: The invention relates to a protective circuit for an electrical device operated in particular in an explosion-hazard area, with a limiting circuit connected downstream of a pair of input terminals for limiting an output voltage present at a pair of output terminals and/or an output current delivered at the output terminals below a threshold value and a shorting circuit, which shorts the output or input terminals when a threshold value is exceeded, the control signal that controls the limitation originating from the same place as the signal that triggers the shorting circuit, and with a measuring circuit, which uses the output voltage or the output current to provide a control signal, which is fed on the one hand to a final control element for reducing the output voltage or the output current and on the other hand to the shorting circuit, the measuring circuit comprising a ZENER diode and/or a measuring resistor and the control signal being a voltage that is in particular a transistor-amplified or impedance-co

Abstract: The invention relates to a switching device for galvanically isolated 1:1 transmission of a direct current signal, with a transformer comprising a primary coil and a secondary coil, wherein the primary coil is powered with alternating current derived from an input direct current and the current induced in the secondary coil is rectified, and with a correction device for compensating transmission losses. To provide a DC transducer free of auxiliary energy, in which the output current is as close to equaling the input current as possible, it is proposed that the number of turns on the primary coil should be greater than the number of turns on the secondary coil.

Abstract: The invention relates to a protective circuit for an electrical device operated in particular in an explosion-hazard area, with a limiting circuit connected downstream of a pair of input terminals for limiting an output voltage present at a pair of output terminals and/or an output current delivered at the output terminals below a threshold value and a shorting circuit, which shorts the output or input terminals when a threshold value is exceeded, the control signal that controls the limitation originating from the same place as the signal that triggers the shorting circuit, and with a measuring circuit, which uses the output voltage or the output current to provide a control signal, which is fed on the one hand to a final control element for reducing the output voltage or the output current and on the other hand to the shorting circuit, the measuring circuit comprising a ZENER diode and/or a measuring resistor and the control signal being a voltage that is in particular a transistor-amplified or impedance-co

Abstract: An ultrasonic filling level sensor (1), has an elongated measuring chamber (2), which is provided with an opening (3) at each of its two ends, wherein a liquid has the same filling level as outside the measuring chamber (2). The sensor includes an ultrasonic transceiver (6), which is associated with one end of the measuring chamber (2) and the emitted sound signals of which are reflected at the surface of the liquid and at a calibrating reflector (5) and received by the ultrasonic transceiver (6), in order to determine the filling level from the relationship between the transit times of the two signals. It is provided that the cross-section of the measuring chamber (2) and the nature of a wall of the measuring chamber are made to suit the properties of the liquid in such a way that, even in a tilted position of the measuring chamber (2), the surface of the liquid forms a meniscus (14) which forms a reflection portion directed toward the ultrasonic transceiver (6).

Abstract: Inductive proximity switch has a first transmitting coil (S1) and a first receiving coil (E1) of a receiving coil arrangement. The transmitting coil (S1) transmits an exciting field inducing eddy currents in a metallic trip (1) brought into the vicinity of the proximity switch. The eddy currents generate a voltage-inducing eddy current field in the first coil (E1) of the receiving coil arrangement. The first coil E1 and a second coil (E2) of the receiving coil arrangement are disposed and connected so that the exciting field generates a differential voltage (3), in the receiving coil arrangement. A pair of compensating coils includes the second coil (E2) of the receiving coil arrangement and a compensating coil (S2) connected in series with the transmitting coil (S1), the pair of compensating coils being isolated from the eddy current field.

Abstract: A proximity switch having a coil former (3) which is fitted with at least one coil (4, 5, 6), has an associated board (8) and is held by a plastic housing (1), and having an electrically conductive shield (2) between the coil former (3) and the inner wall of the plastic housing (1), with the shield (2) making electrically conductive contact with a circuit (9) which is mounted on the board (8), wherein the shield (2) is formed by an electrically conductive inner wall coating on the plastic housing (1).

Abstract: Proximity switch with a coil arrangement having at least one coil and an evaluation circuit arranged downstream of said coil arrangement for obtaining a switching signal when a trip feature of the coil arrangement approaches a desired response distance, wherein the at least one coil is formed by coil sections (8) connected electrically in series, preferably disposed next to one another, axially in parallel, with a same winding direction.

Abstract: A a converter has a head part (1), which can be connected to an external data bus, and one or more connection modules (2), which can be connected to it by way of plug-in mounting in the form of rows. The head part (1) has a plug-in connection (3) with plug-in contacts (4) associated with an internal data bus; each connector module (2) has a counter plug-in connection (5) matching the plug-in connection (3) of the head part (1); counter plug-in contacts (6) of the counter plug-in connection (5) are connected to circuit connection contacts (7) for the connection of a circuit support (8) having an electronic circuit and to plug-in contacts (4) for the connection of the counter plug-in contacts (6) of a further connection module (2); each connection module (2) has at least one device connection (9) for the connection of an actuator or a sensor, which communicates via a bus.

Abstract: Electronic proximity switch with a member (1) generating an alternating electromagnetic field, which is excited by an oscillator (2), an influencing of the alternating field, induced by approach of a trigger, being evaluated by an electronic signal-evaluation stag (8), including an amplifier stage (5), for emission of an output signal. The signal to be evaluated, which is obtained by a member (3, 4) influenced by the electromagnetic field, is mixed with the oscillator frequency before its evaluation.

Abstract: An inductive proximity switch having a coil situated to the rear of an “active” housing wall and belonging to a receiver circuit, whose signal changes as a metallic object approaches, the coil being operatively connected to a switching amplifier which changes its switching state when the object reaches a predetermined distance. In order to reduce the influence on the switching distance of any covering of the active surface with welding dust, there is a supplementary sensor, associated with the “active” housing wall (2), to provide electronic compensation for changes in the receiver signals produced by metallic deposits, especially ferritic deposits, on the “active” housing wall (2).

Abstract: A fault current switch with a total current converter (W), whose primary circuit (1) consists of the incoming and outgoing lines of the circuit to be monitored, and whose secondary winding (2) is connected with a test circuit (P), with an electromagnetic switching device (H) for shutting off the circuit to be monitored if a fault current appears, with the working current of the holding device (H) being switchable by a switch (S1) that is supplied for the purpose with a control signal by test circuit (P), and with a power supply (EV1) for the test circuit (P) and the switch (S1). In order to make such a fault current switch both less prone to wear and also more functionally reliable, a second switch (S2) is connected in parallel with the first switch (S1), likewise for switching a working current of the switching device (H), the second switch (S2) being energized by the test circuit (P) with a second control signal that differs from the first control signal.

Abstract: A mounting base for an associated inductive proximity switch, with the mounting base having an approximately beaker-shaped plastic housing so constructed that the switching behavior of the proximity switch is independent of the respective mounting surfaces. A metal ring is disposed internally on a base bottom of the mounting base, with a diameter of the ring being approximately equal to transverse dimensions of the proximity switch. The metal ring is advantageously located in a corner area of the base bottom and a jacket surface of the mounting base.

Abstract: An inductive proximity switch contains an oscillator that generates an alternating magnetic field and which, when a trigger penetrates the alternating field, changes its oscillating state. An evaluation circuit uses the change in state to generate a switching signal to control a load switch. To achieve a proximity switch response distance that is as large as possible regardless of the trigger material and the ambient temperature, two sensing coils are located in the alternating field to detect the difference between voltages induced in them. The sensing coils are designed so that the alternating voltage differential becomes zero at a desired response distance. When the alternating voltage differential is zero at an input of oscillator amplifier, the oscillator abruptly changes its oscillating state. The change in oscillation state is detected by the evaluation circuit and converted into a binary switching signal for the load switch.

Abstract: In an electronic switch, preferably operating with zero contact, an electronic load switch (3) is controlled by a sensor stage (1), with the switching elements being located in an IC circuit (200) between sensor stage (1) and load switch (3), said circuit (200) containing an inverter stage (7) which, when switched on and off, changes the operating mode of the switch from that of a "closer" to that of an "opener." To reduce the number of IC contacts required for this purpose, provision is made such that switch input (10) for turning on inverter stage (7) is connected inside the IC to IC output (27) of second driver stage (12) and that this IC output (27) is connectable to the operating potential to change the "opener" or "closer" operating mode through an IC-external short-circuit jumper (28).

Abstract: An electronic proximity switch orientatable in various response directions includes a sensor housing, a rotatable angle member and a connecting piece, with the rotatable angle member being selectively attachable to the sensor housing in two different positions. A base member is provided which is adapted to be mounted to the rotatable angle member at an installation site, with the base member being selectively lockable in at least four rotary positions. The entire electronic circuitry is accommodated in the sensor housing and the base member is constructed as an assembly block, with a plug being rotatably disposed within the connecting piece. The assembly block carries a locking fastener which is receivable in passages provided in the connecting piece so that the rotary position of the rotatable angle member can be rotatably locked in a stepwise fashion and a rotary position of a plug can be rotatably locked in an infinitely variable manner.

Abstract: An electronic proximity switch dependent upon a magnetic field includes an HF resonant circuit adapted to be influenced by an approaching magnetic trigger. A coil arrangement includes a member drivable into magnetic saturation, with the member including an amorphous or predominantly amorphous metallic band of high permeability. A coil bobbin for accommodating the resonant circuit coil and the drivable member is made of a synthetic resin enriched with a pulverulent permeable material.

Abstract: An electronic switch includes a sensor for sensing external conditions and an integrated circuit for evaluating the sensor signal from the sensor. The integrated circuit has a short circuit interrogation device and delivers a signal indicating the switch state of a load switch to an IC output. The integrated circuit transmits a short circuit signal indicating a short circuit to a short circuit display LED. The short circuit display LED is directly connected to another IC output terminal to display the short circuit so that an integrated circuit can operationally be switched between three LED displays for a switch state, a short circuit and a operation.

Abstract: An inductive proximity switch in which a quartz oscillator is connected to a sensor resonant circuit having a sensor coil which is adapted to be influenced by the approach of electrically conductive nonmagnetic nonferrous metal (NF) objects and ferromagnetic metal (FE) objects. A detecting circuit detects when the sensor resonant circuit has an impedance which is indicative of either an NF object or an FE object at a predetermined switching distance from the sensor coil, thus causing the proximity switch to exhibit the same switching distance for both NF and FE objects. The oscillator frequency and the impedance of the sensor resonant circuit at the oscillator frequency are respectively set to be equal to a critical frequency and a critical impedance value at a critical response point defined by a point where impedance-frequency characteristic curves of the sensor resonant circuit under the influence of NF objects and FE objects at the predetermined switching distance intersect.