Abstract: The invention relates to a position monitoring device for establishing the position of a first part with respect to a second part, having a transceiver at the first part for emitting an interrogation signal and for receiving a response signal that can be emitted in reaction to the interrogation signal by a transponder, wherein a screen that attenuates signals between the transponder and the transceiver is provided, two members of the group consisting of the transceiver, the screen and the transponder being movable relative to one another.

Abstract: The invention relates to a position monitoring device for establishing the position of a first part with respect to a second part, having a transceiver at the first part for emitting an interrogation signal and for receiving a response signal that can be emitted in reaction to the interrogation signal by a transponder, wherein a screen that attenuates signals between the transponder and the transceiver is provided, two members of the group consisting of the transceiver, the screen and the transponder being movable relative to one another.

Abstract: A device with a safety circuit with an armature activated by a solenoid activates an electromagnet. The device has a switch connected in series to the solenoid, a device temporarily interrupting application of the voltage, first and second clock generators, first and second resistors, and a current detection switch. DC voltage is applied to the solenoid when the switch is closed. The voltage is interrupted when a predetermined current flowing through the solenoid is detected. The first clock generator actuates the switch during a predetermined first clock cycle. The detection switch detects current flowing through the solenoid. The first resistor, in conjunction with the response threshold of the current detection switch, determines the holding current for the armature. The second resistor generates an attraction current for the armature when activated by the second clock generator in a predetermined second clock cycle partially overlapping the first clock cycle.

Abstract: An apparatus for detecting the position of an object moveable along a predetermined travel path. The apparatus includes an acoustic signal waveguide, a signal input coupler, at least one signal output coupler, and means for generating. The acoustic signal waveguide extends along the travel path and having a predetermined, uniform speed of propagation of sound. The signal input coupler is located on the moveable object, to couple a clocked acoustic signal into the acoustic signal waveguide. The at least one signal output coupler is arranged at one end of the acoustic signal waveguide and is connected to an evaluation unit for determining the propagation-time of the sound signal from a position at which it is coupled in to the at least one signal output coupler and for generating a signal representative of the instantaneous position of the moveable object on the travel path.

Abstract: The invention concerns a device for actuating an electromagnet, in particular for a safety circuit, which has an armature which is activated in accordance with the actuation of a solenoid; comprising

Abstract: The invention relates to an apparatus for detecting the position of an object moveable along a predetermined travel path, comprising: an acoustic signal waveguide extending along the travel path and having a predetermined, uniform speed of propagation of sound; a signal input coupler located on the moveable object, to couple a clocked acoustic signal into the acoustic signal waveguide, at least one signal output coupler being arranged at one end of the acoustic signal waveguide and being connected to an evaluation unit for determining the propagation time of the sound signal from a position at which it is coupled in to the at least one signal output coupler and for generating a signal representative of the instantaneous position of the moveable object on the travel path, wherein the signal input coupler couples in, as acoustic signal, adjacent pulses having a varying time interval.

Abstract: The invention relates to an apparatus for detecting the position of an object moveable along a predetermined travel path, comprising: an acoustic signal waveguide extending along the travel path and having a predetermined, uniform speed of propagation of sound; a signal input coupler located on the moveable object, to couple a clocked acoustic signal into the acoustic signal waveguide, signal output couplers at both ends of the acoustic signal waveguide and each being connected to an evaluation unit for determining the propagation-time difference of the sound signal from a position at which it is coupled in to the signal output couplers and for generating a signal representative of the instantaneous position of the moveable object on the travel path, wherein a calibration signal input coupler connected to a calibration acoustic signal generator for a calibration acoustic signal is provided on one of the signal output couplers, the evaluation unit calculating a correction variable for subsequent determinat

Abstract: The position of an object which is moved along a prescribed path, for example an elevator cage, is continuously and accurately monitored by coupling an acoustic signal generator carried by the object to an acoustic signal conductor which extends along the path, the acoustic signal conductor being characterized by the velocity of sound propagation therealong being uniform and constant. The position of the object is calculated by processing signals generated by transducers located at the opposite ends of the acoustic signal conductor, the signal processing determining the delay between receipt of a sound signal originating at the object at the opposite ends of the conductor.