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 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 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.

Abstract: An inductive proximity switch including an oscillator circuit with a frequency resonant circuit (1) determining the frequency and with an impedance member (7) determining the amplification, this impedance member containing an impedance resonant circuit with a sensor coil (9) that can be influenced by the approach of a metallic trigger. In order to provide that the proximity switch has the same activating range for ferrous and nonferrous trigger metals, the resonant frequency (f.sub.o) of the frequency resonant circuit (1) and the critical impedance value (Z.sub.o) of the impedance member (7) are tuned, according to this invention, to the coordinates (f.sub.o,Z.sub.o) of the point of intersection (P.sub.o) of the impedance/frequency characteristics (II, III), resulting for respectively identical activating range, for an NF trigger and for an FE trigger.

Abstract: A proximity switch with a noncontact effect which includes a plug-in adapter having a plug-in socket for the sensor part equipped with a plug-in cable, a ac/dc converter with a core coil connected in front thereof being arranged in the adapter. The adapter is associated with a dc/ac converter located in the basic housing of the main part and includes a core coil connected thereafter. The core coil lie in each case behind the mounting sides of the basic housing and plug-in adapter and transmit by inductive coupling the energy from the main part to the connected sensor part and the signals from the sensor part to the main part.

Abstract: A proximity switch operating on a non-contact basis including a terminal-side main part set in a base housing and a sensor part set in a probe. To enable a selection of the response direction, the probe may be adjusted in different positions on the base housing, to which the probe is designed or arranged as a component insulated on all sides which, by way of individual in-built core coils is inductively coupled with a core coil set in the base housing.

Abstract: A fault current circuit breaker for monitoring electrical circuits having a total current converter with a primary circuit including supply and return leads which are to be monitored and a secondary winding acting upon an electronic limiting value circuit which controls an electromagnetic retaining device. Switch contacts are provided for switching the circuit to be monitored when a predetermined fault current is exceeded. In order to enable self-monitoring, a current is briefly and periodically fed into an additional winding of the total current converter, with the current simulating a fault current, and a pulse voltage which appears at the output of the electronic limit value circuit due to the current in the additional winding is fed to an evaluation circuit, which causes the switch contacts to open in the absence of periodic pulses coming through the electromagnetic retaining device.