Abstract: An oscillator circuit for a sensor, with a tuned circuit and an operational amplifier, the electrical oscillation of the tuned circuit is capable of being tapped between a first terminal and a second terminal of the tuned circuit, and the first terminal of the tuned circuit being connected to the noninverting input of the operational amplifier and the output of the operational amplifier is fed back to the noninverting input of the operational amplifier. The oscillator circuit is designed to improve the dynamic behavior of the oscillator circuit by the second terminal of the tuned circuit —at least in terms of AC voltage —being directly connected to the inverting input of the operational amplifier.

Abstract: An electronic switching device, which operates without contact, includes a single sensor element (1), a clock generator, which can be provided internally or which can be connected externally, an evaluation circuit (2), and an electronic or electromechanical switch (3), which is provided on an output side. The evaluation circuit (2) includes diversity processing units (4, 5), and a checking unit (6), wherein an output signal of the sensor element (1) is delivered in succession to the processing units (4, 5), and that output signals of the processing units (4, 5) are checked for consistency by the monitoring unit (6). Advantageously, with only a single sensor element (1), category 4 of EN 954-1 or safety level SIL 3 of EN 61508 requirements can be achieved.

Abstract: An oscillator circuit for a sensor, with a tuned circuit (2) and an operational amplifier (3), the electrical oscillation of the tuned circuit (2) is capable of being tapped between a first terminal (4) and a second terminal (5) of the tuned circuit (2), and the first terminal (4) of the tuned circuit (2) being connected to the noninverting input of the operational amplifier (3) and the output (6) of the operational amplifier (3) is fed back to the noninverting input of the operational amplifier. The oscillator circuit is designed to improve the dynamic behavior of the oscillator circuit by the second terminal (5) of the tuned circuit (2)—at least in terms of AC voltage—being directly connected to the inverting input of the operational amplifier (3).

Abstract: An electronic switching device, which operates without contact, includes a single sensor element (1), a clock generator, which can be provided internally or which can be connected externally, an evaluation circuit (2), and an electronic or electromechanical switch (3), which is provided on an output side. The evaluation circuit (2) includes diversity processing units (4, 5), and a checking unit (6), wherein an output signal of the sensor element (1) is delivered in succession to the processing units (4, 5), and that output signals of the processing units (4, 5) are checked for consistency by the monitoring unit (6). Advantageously, with only a single sensor element (1), category 4 of EN 954-1 or safety level SIL 3 of EN 61508 requirements can be achieved.

Abstract: A circuit is described for monitoring the faultless state and/or for detecting the faulty state of a cable railway or chairlift system, with a plurality of monitoring and detection devices (1) and with at least one control and evaluation unit (2), the monitoring and detection devices (1) being series-connected to one another and to the control and evaluation unit (2) and having the potential to be interrogated with respect to their state, especially with respect to their operating state. To be able to meet safety requirements which are as high as possible and at the same time to require only a small installation space, each monitoring and detection device (1) has several different influence areas (3) and several signal outputs.

Abstract: An electronic proximity switching device with a proximity indicator and with an electronic switch which can be controlled by the proximity indicator. A plurality of these switching devices can be series connected without an unacceptable voltage drop occurring on the series connection when the switching devices are conductive, by the electronic switch of each switching device being connected to one input (2) of an AND element (3), another input (4) of the AND element (3) representing a control input (5) of the switching device, the output (6) of the AND element (3) representing the output (7) of the switching device, and load current flowing via the AND element (3) in the conductive state of the switching device. In other words there is AND element (3) in addition to an inductive proximity switch (1).

Abstract: An electronic switching device which can be connected via an outside conductor to one pole of a voltage source and only via one other outside conductor to a terminal of a consumer, in which the other terminal of the consumer can be connected to the other pole of the voltage source, therefore a two-wire switching device, with a proximity indicator (1) which can be influenced from the outside, with an electronic switch (3), which can be controlled by the proximity indicator (1) via a switching amplifier (2), and with operating voltage supply circuit (4) for making available the operating voltage required by proximity indicator (1), and optionally by the switching amplifier (2) (=internal operating voltage), the operating voltage supply circuit (4) an having in-phase regulator (5) and proximity indicator (1) and the switching amplifier (2) being connected to the output of the in-phase regulator (5).

Abstract: An electronic switching device such as an inductive proximity switch includes an externally influenced oscillator detector with its output connected to a switching amplifier. An electronic switch connected to the output of the switching amplifier responds to the amplifier signal and controls a state indicator. Upon the influence state of the detector crossing a predetermined threshold, the switching state of the electronic switch is reversed, and the detection state of the oscillator is reflected in switching states of the electronic switch and indicated by the state indicator. A second state indicator indicates whether or not the reading from the oscillator is in a "safe range" in which variations in ambient conditions cannot cause a false reading.

Abstract: An electronic detection circuit such as a proximity switch or flow detector uses a presence detector with complementary outputs and one or more electronic switches to provide either normally-open or normally-closed operation based on the polarity of the supply connections to the device. In one embodiment, two electronic switches are provided, each operating in response to one of the complementary outputs, with each switch connected to provide current flow in a mutually opposite direction between the supply connections upon activation. In another embodiment, a single electronic switch is provided, and is connected through a diode matrix to the complementary outputs.

Abstract: An electronic switchgear operating contact-free, having a presence indicator which can be externally affected, a switching amplifier disposed downstream of the presence indicator an electronic switch controllable by the presence indicator via the switching amplifier a supply circuit for the provision of the supply voltage for the presence indicator and for the switching amplifier and a delay circuit preventing activating pulses. The supply circuit has a voltage and/or current regulator. In the electronic switchgear in accordance with the invention activating pulses are prevented with a higher degree of assurance than in the state of the art, namely based on the fact that the delay circuit becomes active, i.e. the delay time starts, only after the voltage and/or current regulator has started to operate.

Abstract: A contact-free operating electronic switchgear, having an oscillator capable of being externally affected, a switching amplifier with at least two operating units disposed downstream of the oscillator, an electronic switch, which can be controlled by the oscillator via the switching amplifier, and a supply circuit for the provision of the supply voltage for the oscillator and for the switching amplifier, is shown and described. In electronic switchgear operating contact-free in accordance with the invention the maximum switching frequency is considerably increased in that a control circuit is provided between the two operating units of the switching amplifier and the oscillator and that the oscillator is controlled by means of the control circuit in such a way that the oscillator also oscillates in the affected state.

Abstract: A frequency-independent phase advancing system controlled by an external voltage, including a control loop of which the return circuit comprise a phase lagging circuit controlled by the external voltage, said external voltage undergoing a correction by circuits compensating the effect of frequency upon the lagging circuit.