Homemade Ultrasonic Cleaners!

[whistule]

Is it possible to make a basic ultrasonic cleaner with a tank and a hifi speaker? Or would it be too loud for the neighbours?

[marsfrogie]

Technically, you should be able to construct an ultrasonic cleaner out of a speaker that is capable of exerting extremely high frequencies. However, you would only be using the magnet structure of the speaker to create an ultrasonic transducer. The sound waves would then only be sent through the liquid medium and not sent directly to the air. I believe you would need something in the range of 24000Hz+.

[thesound]

MB Quart "Q" series tweeters are capable of going up to 32,000hz, so if you could get your hands on a pair of those you're good to go. Not sure on what kind of device you'd be using to actually transmit that frequency though. (Maybe a sonar?)

[c_gismo]

I would think that the specs of a standard Hi-Fi system would be exceeded by running them in a fluid thicker than air, for which they are designed. A speaker operates by vibrating back and forth at the frequency of the electrical circutry driving it. The vibrations of the speaker form pressure waves in the air at that frequency. These pressure waves are the sound. The problem is that the air offers very little resistance to the vibrating speaker, where the ultrasonic cleaning fluid will offer a lot of resistance. Think of a 30 mph gust of wind. A person can easily resist it, but a 30 mph stream of water will will wash a person away. Vibrating the ultrasonic cleaning fluid will take a lot more power (energy) then vibrating the air. Even if a Hi-Fi speaker can do the job, the standard Hi-Fi circutry definitly could not. Power, if I remember correctly, is the product of current and voltage. Trying to drive the speaker would probably fry standard circutry. Specilized circutry will be required, which will drive up the cost.

[whistule]

Looks like a mamoth hi-fi is the only way forward! - just kidding.

It would be interesting to see how it's done in commercial ultrasonic cleaners. Is there some sort of paddle in the liquid or is the vibration transmitted through the tank itself? Presumably the latter would require more power. By speciallised circuitry do you mean bigger and more power amp and speaker driver?

[c_gismo]

The power required to drive the speaker may exceed the available power from a stock Sony or Pioneer Hi-Fi. In that case, one would need a specilized amp, whether custom made from Radio Shack transisters or some kind of stock industrial unit.

This is all just speculation, though, on my part. I have no experience with the inner workings of electronics. I could be completly wrong.

I wonder if someone out there sells a stock underwater speaker for swimming pools that can be hooked up to a stock stereo. That would answer the question about the circutry and speaker.

[whistule]

I notice you can get units you can drop into existing tanks.

[skiddz]

How 'bout one of those transducers folks are installing in their home theaters? The kind you bolt to the chairs etc to really feel the sound.

I think hi-end hot tubs have similar technology that transmits the sound through the structure and the water.

Maybe a high-performance RC car motor with a slighty unbalanced load on it? I know some of the motors I've got will do upwards of 30k revs on 7 cells (8.4 volts)

[skiddz]

Did a little digging on this subject while I was on hold this afternoon. (Glad it was an 800 number. 35 mins I was waiting!) I found a company that makes transducers for just this application and I was able to get a lot of info on the basics of building a cleaner. A couple key issues to consider.

1st, the way the transducer is driven. Evidently they can literally shake themselves apart if not driven correctly. The "ideal" way is to get a transducer with a feedback tap and build a driver circuit that monitors that feedback to keep the transducer running where it's supposed to. I got a few schematics from the transducer folks for some basic driver circuits and then plied my engineer neighbor with beer to check 'em out. He's going to run something up for me in the next week or so that'll do the trick.

2nd, attachment of the transducer to the cleaner basin itself. Usually they're attached with some sort of adhesive, but can also be bolted in, depending on the transducer.

I'm going to keep digging and maybe run up a test rig to check out the feasibility of a home-brew ultrasound cleaner...

[murphy]

i am interested in building an ultrasonic cleaner and found a reply from skiddz where there was mention of a web site that had information on transducers and construction tips. BUT he failed to give any information as to the name of the site or any links... AND the "pm" feature is disabled so i can not contact him directly. so, kiddz; if you happen to see this you can reply to me directly at chuckstone32@hotmail.com. thanks.