Ultrasonic proximity switch

A device for detecting an actuator by sonicating the actuator with sound waves by a sensor, in particular in a safety application, wherein

• the sensor and the actuator are movable relative to each other,
• the sensor comprises a sound wave transmitter, a sound wave receiver and a computing unit, wherein the sound wave transmitter and sound wave receiver can be realized as a single component, and
• the sound wave transmitter is intended to transmit sound waves in the direction of the actuator and the sound wave receiver is intended to pick up the sound waves reflected by the actuator and convert them in-to an analog signal,
• wherein,
• the computing unit converts the analog signal into a digital signal and implements the detection of the actuator by comparison with a reference signal.

A method for recognizing an actuator with the aid of sound waves which are transmitted by a sound wave transmitter and received by a sound wave receiver, comprising the following steps;

• transmitting sound waves to a pattern of the actuator,
• receiving the sound waves reflected by the pattern of the actuator by a sound wave receiver,
• converting the sound waves into an electrical signal,
• comparison of this signal by a computing unit with a reference signal stored therein,
• generation of a binary signal as a result of the comparison by the computing unit and determination of the detection of the actuator on the basis of the binary signal.