Single ultrasonic transducer switching to Rx and Tx

[miskol]

share ultrasonic tx circuit

miskol, what I said was, what you have is "good enough" considering the information we have.

Your intial design would be the base for a much better one (we would add SPI, I2C, AGC, tuned LC tank for the peizo at the very least)

Getting a basic sonar setup working does not take much effort, but making it precise/or sensetive is VERY hard work.

ohh i see, sorry for misunderstanding. ok then give me some time to update and recompile more informations about what i have done.

 

[vsmGuy]

tx-rx transducer

miskol, well if you need help, atleast I am available

 

[miskol]

single ultra sonic transducer

i appreciate that

im sorry, i never forget to update here, just kinda busy right now.

 

[vsmGuy]

resonance ultrasonic transducer drivers schematic

well .. any luck?

 

[miskol]

single transducer ultrasonic circuit

For my setup, i used a transducer with these characteristics (from datasheet):

Center Frequency (Fc) (KHz) 335.0±10 KHz
Nominal Impedance at Fc (Ohm) 1000
Capacitance at 1KHz (pF) 250±20%
Max.Driving Voltage 50 Vp-p (2% Duty cycle tone burst)

For my setup:

Excitation freq: 333.3kHz (2 pulse for each time transmitting)
Driving Voltage: 15V pulse

For transmitter part, I used TLE2141 to drive 5V mikroC pulse into 15V transmitting pulse.

For receiver part, TLE2142 are used for the two-stage amplifiers. Both stages have a gain of 150.


using the SPDT switch is 1 way to be able to achieve a single transducer for both transmitting and receiver. i found that there's another way which im currently trying to do and will report back if i succeed. one of my goal is to create the easiest method for transceiver switching circuit. other goals can still be added

 

[jsphgllwy]

Hi,
I am embarking on a similar project as this. Namely, I am going to be attempting to analyse the spectral response from an ultrasonic transducer by firing at a target through water. I am still in the early days and still at the point of setting up a water bath etc. However, my transducers operate at much higher frequencies than the ones under consideration in this project. To be exact, they have a centre frequency of ~3.5 MHz. The DAQ cards in the lab I have access to are nowhere near meeting this requirement and I am unaware of how to get round this as I do not have thousands to spend on a faster DAQ card!
As mentioned before, the hardware requirements of my project will be similar to those mentioned above, as I too am switching between Tx/Rx and using only one transducer for both purposes.
Anyway, I am new to this forum, so pleae don't be mad if I shouldn't be posting on someone else's thread but I have read it through and expect to be facing many of the same problems as mentioned above!
I would really appreciate some help with regards 'getting around' the DAQ card issue!
Thanks

 

[FvM]

You didn't explain, why you want to "analyse the spectral response" of your transducer and what's the project objective. So I don't see if it's actually necessary to perform digital acquisition of transducer signals. Many questions, e.g. transducer pulse response can be answered from a simple analog oscilloscope measurement. Most basic ultrasonic instrumentation has been development before and during world war II, without digital tools.

 

[betwixt]

Maybe I'm missing something here. Is the SPDT switch in the 4053 just routing the signal from a single transducer or are there two transducers? If it's one, being used to transmit then listen for the echo, where is the input of the receive amplifier connected when transmitting? Is it left floating or grounded?

Brian.

 

[FvM]

These details haven't been mentioned in the discussion, also the timing of the switching signal isn't clear. But whatever has been done in this regard, you can expect some direct Tx signal crosstalk anyway and you always get the said "ringdown" signal. So most likely, you have to block the receiver for a certain amount of time.

In the "single-sensor" waveform shown at top of the thread, the echo signal doesn't look bad. The receive amp is clipping initially but recovering fast. The problem arises of course, if you try to minimize the dead zone. But no requirements have been told in this regard, too.

P.S.: The signals show an echo distance of about 6 cm. It should work at least down to 2 cm without changing anything.

 

[arjithesh]

Re: ultrasonic transducer driver circuit

hi...

Try using TI's TX810 chip for ur soln.