Has anyone have done the ultrasonic generator circuit with range 6-10m?
I intend to use ICL8038 and TL082 amplifier with transistor push-pull to output ultrasonic 22khz with >Piezoelectric ultrasonic as link:
http://www.tantexcorp.com/Open-Struc...ensor-767.html
Anyone know that I can do this with receiver at distance 6-10m with respect to transmitter? What is the main factor (power of output or piezoelectric)?
Thanks!
Long ago I made from a Japanese kit an ultrasonic transmitter and receiver. It sent on/off commands over ~15 meter range.
Its transducers operated at 40 kHz. The driver was a simple CD4001 with a 9V battery, the receiver used an opamp and a CD4013 to decode the commands and alternate the on/off for a relay.
Recently I made a 22 kHz dog repeller which has ~ 1W output power. To tune the transmitter driver I used another transducer connected to an oscilloscope. With 10 mV sensitivity, the range was well over 10 meters.
To extend the range of such simple devices, the best way is to use a tuned audio amplifier in the receiver. Trying to increase the transmitter output power is not recommended, also the high drive power can break the piezo-ceramic resonator in the transducer.
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Also you can use a small horn or a parabolic dish to direct the ultrasonic power to the receiver.
While ago I had an Whistle Key Finder that works at more than 15m.
http://www.alibaba.com/countrysearch...ey-finder.html