This is usually a piezo electric module eg on the

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: illator (1) External voltage (6) Evaluation unit (2) Internal constant voltage supply (7) Triggering stage (3) Active zone (ultrasonic transducer) (8) Switching status display (4) Switch output (9) Output stage with protective circuit (5) Fig. 7.1.1: Block circuit diagram of an ultrasonic proximity sensor The proximity sensor can be divided into three main modules, the ultrasonic transducer, the evaluation unit and the output stage. A short pulse briefly triggers the ultrasonic transmitter. This is usually a piezo-electric module, e.g. on the basis of piezo-oxides. © Festo Didactic GmbH & Co. KG • FP 1110 107 7. Ultrasonic proximity sensors The ultrasonic transmitter emits sound waves in the non-audible range at any frequency usually between 30 – 300 kHz. In most cases, the ultrasonic transmitter changes from emission to reception, i.e. now operating in the sense of a microphone. Filters inside the ultrasonic proximity sensor check whether the sound received is actually the echo of the emitted ultrasonic waves. 1 V 2 td to te tp Emission pulse (1) Pulse duration...
View Full Document

This note was uploaded on 11/01/2012 for the course CHEMICAL 102 taught by Professor Jamesrodriguez during the Spring '12 term at Universidad Politécnica de Cartagena.

Ask a homework question - tutors are online