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graffian
21-11-2012, 05:07 AM
There are lot's of knowalgable peopel on here, I thought maybe someone knew a bit about ultrasonic baths.
I bought one that doesn't work. I bought it as non runner figuring I will be able to sort it. Main reason I bought
it was to clean my bike chain, how lazy is that, but I suspect it will get plenty of use.

I had a little look and, well, I have no idea.
I gather you don't run the transducers without liquid in the bath, so you don't run them upside down, which I need to do to access the circuit boards unless I extend all the wires.
Can I replace the transducers with a resistance while I fool around with it?
Is there a simple test to see if the transducers work?

The timer board works as far as counting down the time and operating the heater up to set temperature and for set time, but no sign of life from the ultrasonic thingies.

Jonathan
21-11-2012, 11:39 AM
Can I replace the transducers with a resistance while I fool around with it?

Possibly, but at the frequency the circuit drives it at the transducer will be more inductive than resistive. Have you got an oscilloscope?

Mad Professor
21-11-2012, 11:41 AM
Last week my Kerry KC2 ultrasonic bath started to fail on me, so I have brought a new one to replace it.
My old one still works, but does not seem anywhere as powerfull as it once was.
I have not yet pin pointed what the problem is, so I don't know if the transducer is starting to fail, or a problem with the driver board.
With mine, I disconected the transducer, and powered up the unit, and using my DVM I would get a reading of around 600vac.
I used my picoscope 2202 to test the low voltage side of the signal gen for the drivers, and thats was switching at 40Khz, as expected.
As my picoscope does not support high voltage, I am unable to see what the wave form looks like to the transducer.

If you can open up your ultrasonic bath, and take some high rez pictures, we might be able to help you find what has failed.

Best Regards.

Jonathan
21-11-2012, 12:02 PM
As my picoscope does not support high voltage, I am unable to see what the wave form looks like to the transducer.

Just use two resistors to make a voltage divider to divide it by about 20, or whatever is safe. Clearly you'll need to pick very high resistances to ensure only a tiny current is drawn from the circuit.