Is it worth to use piezo tweeters for an ultra sound cleaner?

[GoranB]

I would like to make a small ultra sound cleaner with piezo tweeters. Can those piezo tweeters produce the frequency of 40KHz?

[konga]

I also have a couple of 43KHz piezo tweeters. How are you going to power them and generate the signal?

[pinkmouse]

This is something I've wondered about too. One of my other hobbies is model railways, and cleaning up an etched brass loco kit is a bit of a pain. An ultrasonic cleaner would be a very useful tool, and though the small ones are pretty cheap, the price seems to rise exponentially as you get to a useful size.

[GoranB]

Originally Posted by konga

I also have a couple of 43KHz piezo tweeters. How are you going to power them and generate the signal?

In my case i want to power them with two TDA2030 based amplifiers, as you can see on the photo on my first post. That should gave me about 40W. Also i have builded an preamp with NE5532. The generator is based on NE555, i have one with fixed frequency on 44KHz, and another one with variable frequency. The most important, i dont know if these piezo's can vibrate on 44KHz. Also the container is very important, i think with variable oscillator is better to try because I can look for a resonance frequency of the water container.
If you have a good sound card You can generate the 44KHz using software like Cool Edit.
BTW, i still dont know what is the desired shape of the signal of 44KHz for sono cleaners, if it should be sine, or square?

[GoranB]

Originally Posted by pinkmouse

This is something I've wondered about too. One of my other hobbies is model railways, and cleaning up an etched brass loco kit is a bit of a pain. An ultrasonic cleaner would be a very useful tool, and though the small ones are pretty cheap, the price seems to rise exponentially as you get to a useful size.

I agree, the small one here in Poland you can buy for 70-100 Euro.
I want to build an water container: 320mm x 50mm x 120mm to clean LP's.

[Hiten]

Originally Posted by pinkmouse

and though the small ones are pretty cheap, the price seems to rise exponentially as you get to a useful size.

Don't want to hijack the thread but this might be related to the thread. Since smaller size ultrasonic cleaners are easily available on ebay, what if we remove the small container and replace it with large one? Will that work efficiently ? I am also thinking of making LP cleaner out of it.
Thanks

[GoranB]

Originally Posted by Hiten

Don't want to hijack the thread but this might be related to the thread. Since smaller size ultrasonic cleaners are easily available on ebay, what if we remove the small container and replace it with large one? Will that work efficiently ? I am also thinking of making LP cleaner out of it.
Thanks

Please feel free to "hijack" the thread. Every opinion is welcomed.

I have never tried something like that. But i think the placement of the transducers on a particular container is essencial, so i dont think that increasing the container will be effective. But maybe im wrong. At work i have several ultrasound cleaners, different sizes and its very difficult to remove the transducers, in some cases they are sticked on the bottom of the container with some special glue .

[GoranB]

I just find out the characteristics for piezo's i have.
Frequency 4,2KHz
Impedance 300 OHM's
Capacitance 24nF
From my experience they can produce much higher frequency. To get 8 OHM's i should connect 40 piezo's in parallel to the output of TDA2030.

[SY]

The impedance at ultrasonic frequencies is not going to be 300 ohms! Working off resonance, the efficiency will be low. You need ultrasonic piezos to do this correctly.

[GoranB]

Originally Posted by SY

The impedance at ultrasonic frequencies is not going to be 300 ohms! Working off resonance, the efficiency will be low. You need ultrasonic piezos to do this correctly.

Thanks, what should i looking for, as You said I need ultrasonic piezos, can you tell me more abt?