Air Coupled ultrasonic transducer transmitter & receiver ciruits

Thread Starter

cuggy

Joined Jan 12, 2005
5
Hi, I've design my ultrasonic transducer circuit to send and receive signals. I used a 555 timer to generate the pulse for my transmitter circuit, and a 2 stage op-am to amplified the receive signals.

The problem is, I want a circuit to start counting when the signal is sent, and stop counting when the signal is receive by the ultrasonic receiver.

Then after the counter stops counting,I want to design some kind of circuitry to tell the data logger the counter has got a number on it that i want to record...

I'm having problems designing a circuits to give me all those functions.

cheers
 

Thread Starter

cuggy

Joined Jan 12, 2005
5
Yes am trying to build a proximity logger,and them get the information to download onto a computer for analyse of the data.
 

MrChips

Joined Oct 2, 2009
30,720
This is more easily done using a microcontroller.

If you want to avoid this route here is a possible solution.

Get a 555 timer circuit running at 2Hz. Use this to trigger/gate a second 555 timer running at the transducer frequency (40kHz). Send a chirp of about 1ms long.

Use the same 2Hz signal to trigger your time-of-flight counter. You can use the same 40kHz clock to clock your timer.

Use the received signal to stop the counter.
 

Thread Starter

cuggy

Joined Jan 12, 2005
5
I would prefer not to use a micro controller,

and how will I design a counter circuit,and am thinking of using the square wave from the astable to trigger the counting clock
 
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