I'm trying to put an ultrasonic cleaner together and need advice.

[ZackDillon]

Hello!
Let me start by saying I'm not experienced in the world of electronics. I know just enough to be dangerous.

Some time ago I bought a used, not working 40KHz ultrasonic cleaner for next to nothing (1st picture) The generator PCB inside the unit is made by Crest. I replaced all the components that were obviously burned up (3 IC's and about 7 Transistors) . To make a long and irritating story short, it fried immediately when I put power to it. I would like to revisit fixing the original generator in the future (with a lot of help from you folks).

In the mean time I've (on a whim) purchased a used generator on eBay and I'm now awaiting it's arrival. See pics 2, 3 and 4.
I have searched the internet hi and low for ANY information on this generator and have come up with nothing.

My plan\dream is to use this generator to drive the tank I have. I've removed the dead PCB and left the wiring that controls the heater for the tank. The tank has 4, 40KHz transducers (picture 4)with separate leads and a common ground wire.
I know I can destroy my new (to me) generator by running it without a load, or by wiring it to the transducers incorrectly.
My questions are, is anyone familiar with this generator and could shed some light on its specs? I'm pretty sure it's powerful enough to fry my transducers if it were run at full power.
Does anyone recognize the round 3 prong plug? I assume it drives the tank. And how should I test those leads to determine which wire (s) go where.
Does anyone think the white 4 pronk plugs on the back of the generator are alternative power out plugs?
Assuming I get this rig working how do I "tune" the generator to the tank transducers?

My hope is to be ready to wire it to my tank correctly when it arrives next week.
THANK YOU in advance for your time and input.

 

[c_mitra]

Last picture first.

The four crystal (piezoelectric transducers) cannot be run from the same oscillator because they are part of the oscillator circuit and they will always have some small difference of frequency.

They determine the oscillator frequency and there should be four separate oscillator; do they? please take a look and tell us.

Do not run more than a few seconds without a liquid in the tank.

I see that they share the same ground.

If you run it without a liquid, the glue will melt and come off. I need to keep it cool.

I guess each transducer is about 20-40W capable and the total will be around 100W. Do you see any label on the package?

 

[ZackDillon]

I cannot find any markings on the piezoelectric transducers. I have found information that leads me to believe this tank is identical to a Crest 950 HT (Heated Tank) model that produces average 180w, and a peak of 540w.I believe your guess of 40w per transducer is close.
I haven't received the generator from eBay yet, I only have the pictures from the listing (2nd 3rd and 4th picture on my original post) I don't know how many oscillators are in that unit yet. How will I determine how many oscillators it has when it arrives? I'm sorry my questions are so ignorant on this matter, I'm learning a lot from this.
I won't run it without water in the tank, thanks for the warning.

 

[FvM]

The four crystal (piezoelectric transducers) cannot be run from the same oscillator because they are part of the oscillator circuit and they will always have some small difference of frequency.

Not generally true. Provided all four transducers have similar resonance frequency (very likely), they can be usually operated by a common generator/power amplifier.

The generator has to be basically matched to the transducer impedance. The single tuning knob of the shown generator might be a frequency fine tuning or less likely a variable L or C element.

 

[ZackDillon]

What's an L or C element?

 

[ads-ee]

L is an inductor
C is a capacitor
R is resistor
D is diode
etc...

These are the normal designators that are used on a schematic.

 

[ZackDillon]

Okay, thanks

Would I tune it by ear like a carburetor or does the amp meter on the face of the unit indicate the "sweet spot"?

 

[FvM]

I guess the latter.

 

[ZackDillon]

According to FedEx tracking the generator will arrive today.
I'm still unclear on how to wire it to my tank. My plan is to open it up and have a look under the hood so to speak. I think I'll recognize the oscillator (s) when I see it, then follow the wiring to the cord that we see in the pictures for plugging the tank in.
Am I rite to assume that's the "hot" lead for the transducers?
The ground should be easy to identify. I wonder what the 3rd lead on that plug is for? Feedback to the generator? Or is it a wire not used in my application.
Any input from you would be helpful.