After 4 years of extensive use 2 of the transducers seem to have given up the ghost.
If you're somewhat technically inclined, the first thing I would do is a visual inspection, take the covers off, inspect the innards.
Could it be so simple as a contact falling off with vibration?
Next, if not, how do you determine which devices have failed, if so, and how do you replace them?
Fundamental to that is what wattage and frequency are they? Might be on a label.
You can search eBay for 50w ultrasonic transducer say, or whatever variant replacement part. Better than writing off the whole machine! Have a look.
If you had 3, might they be just 35W ones? Etc. Identify & seek to replace, rather than buy a whole new device?
I am slightly surprised to see that just over two years have passed since I bought a couple of transducers from Jaycar sale stock, I'd had to search out stores that still had them.
They were
AU5556 50W 42kHz Ultrasonic Transducer, now out of stock, was $12.96, save $ 62.64 ;-)
I see they still have listed
AU5554 35W 42 kHz, unknown which stores, for $11.94, save $50.96.
But the two AU5556 I got then were obviously old stock, in the sense that on the wider face to be attached to the tank, in contrast to others more modern on eBay &or etc. they didn't come with mounting slugs to be welded to the tank, with bolt ends for the transducer to screw down on to, which you would need to get someone to weld such a piece that short so to allow the transducer mating surface to be flush, perhaps delicate work.
So those would have to be epoxied on solely. Some I gather use a bolt and epoxy, not sure of bolt alone.
(and so there's another possibility - have the transducers merely become detached? Thus again the need for curious inspection!) Find out what's gone wrong! :-)
Anyway, I'd still like to build my own, a large bain-marie from TradeMe, and one can buy 2x 50W 42kHz driver boards, or even with transducers as well, for instance from eBay.
I would build my own wood cabinet around it, I already have several slow geared motors, the slowest 1rpm, and would buy a 12V pump and a filter and taps nozzles hoses as well, etc.
And build a wood enclosure for it. Plus possibly I'd thought an elevating linear motor motor mount, but now I quite like the 90 deg hinge idea on the Real Groovy one too.
And then I thought, OK, I have two transducers which I can get a driver board for, and I can also get a driver board for and with two transducers, so why don't I use 4 on the tank, and then where are the best places to place them so I went researching ...
Inconclusive results, so far, although some ... I'd be interested in any measurements from edges, on which faces, transducers are placed on anyone's commercial devices if they are willing to take their skirts off and inspect, photograph them?
Thanks! :-)
Just a back burner thought project that is yet to take shape!
Cheers!
[Edit: Here's a pic of the Jaycar pair I have stashed.]