Ultrasonic Transducer Usage Question

What're some examples of not being able to use 'em for transmitting?

The xdcrs are piezo crystals - they don't know if they are transmitting or receiving. If you apply a voltage the crystal will deflect, producing a physical deformation. If the crystal is deflected by an external force it will produce a voltage output.

If have designed circuits where these xdcrs were used as both - and it worked well. Virtually all depth finders use a single xdcr, and they also work well.

Hi... I've come across some surplus 24KHz transducers and wanted to know if it is possible to use them for either transmitting AND receiving. I tried some internet searching, but was never able to get a definate answer. It seems that vendors sell some which are meant for receiving and some for transmitting. However, I remember, sometime in the past reading where you COULD use a transducer as both receiver and transmitter. Your thoughts would be appreciated.

Thanks, Jim

On Mon, 14 Feb 2005 23:10:39 GMT, Jim Flanagan wroth:

Jim (the other one) Meyer

You have very little to lose by buying them and trying them out. Hook one up to a signal generator at 24 KHz (5 V peak-to-peak) and hook the other one up to an oscilloscope. Hold them at a separation of 2 or 3 feet, and set the oscilloscope up to show both the transmit and receive waveform. Measure the gain (Vtx/Vrx). Then swap them and see if you see any difference.

These guys are usually very narrow-band, so make sure you are at 24 KHz, and not 23 or 25.

Have fun.

--Mac

Some can be both. But many varieties have one of each and using them for the opposite part works for poo. I have played with many. All the cheapy T/R pair type are best used n pairs.

On 14 Feb 2005 18:09:35 -0800, Winfield Hill wroth:

There are ultrasonic microphones (receiving) that are either too small or too delicate to get any reasonable output from when used as a transmitter.

Not all transducers are piezo disks.

Jim