# what is it and how does it works



## ericrm (Sep 16, 2014)

i removed a bunch of those little vibrating motor(i think thats what they are) from under a medical sonic cleaner. i was hoping to reuse them but i cannot make them work, i plug them on my dc rectifier and nothing then on 110v,still nothing. i dont have the board that were on the cleaner... do anyone know how they work? thank you


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## butcher (Sep 16, 2014)

You will need the amplifier circuit to drive the ceramic piezoelectric transducers, which can run from 20 to 400 kHz.


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## ericrm (Sep 17, 2014)

what your saying is that i absolutely need the board controler that was with them?


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## g_axelsson (Sep 17, 2014)

Yes, you need a piezoelectric transducer driver.

What you have is a bunch of crystals that change shape when a voltage is put over them, put a large and high frequency signal and they start to vibrate in step with the signal. If the frequency is high enough and you mount the transducer at the bottom of a tank you get an ultrasonic bath.

Göran


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## ericrm (Sep 17, 2014)

ok ... lets wish that i can manage to get those board back


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## justinhcase (Sep 17, 2014)

A good way to vibrate material at a set frequency they would be fun for a shaker table or jig.you could control the frequency of oscillation very precisely
Cant they operate in reverse.
Put out a current when compress.I would not suggest it for audio piezoelectric transducers but they look chunky enough to absorb a good impact.
Start off monitoring for an electrical out put when pressure is applied start low and work your way up.
a Home made impact sensors is an interesting project.


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## Irons (Sep 17, 2014)

You can mount them on the front bumper of your car and connect the leads to your body, that way, when you fall asleep and hit the bridge abutment, the shock from the transducer will wake you up. :mrgreen: :mrgreen:


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## ericrm (Sep 17, 2014)

i dont have a single clue about what your talking :roll: , i have look back at job and those were the only board that i kept from the whole machine. lucky me my boss havent sold the smelter yet. is there a way to make them work with that board alone?


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## g_axelsson (Sep 17, 2014)

It looks like a quite simple circuit if that is all that is needed. For someone with a bit of electronic knowledge it should be possible to trace the circuit and the function although it could take some time.
I don't know if there should be something else too to control the oscillation, I've never studied a piezo transducer and the drivers before so I can only say good luck!

Göran


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## butcher (Sep 17, 2014)

How many ceramic crystals were driven from that board?
If this was the only board, it looks like four, as the four output transistors, (or possibly mosfets...), I cannot really tell what they are, without seeing and looking up their numbers.

Looks like two transformers, my guess is one for the power supply to transform high voltage Ac to a DC voltage to run the circuit, The four diodes in a row are possibly set up as a bridge rectifier to convert the AC to a DC voltage.

The other transformer and its related circuit is possibly used to step up the frequency.

The two fuses marked L1 (line one input?) and L2 (line 2 input?) are possibly input fuses, these may go to the input of one of the transformers, the other side of that transformer probably goes to the four diodes (bridge rectifier) to produce the circuits DC voltage, this can give you a clue to the 110volt AC voltage input.

Tracing the transistor output (or whatever these are) (drivers?) should give you a clue to the outputs that go to the ceramic crystals you wish to drive.
Check numbers on these (transistors or whatever they are), and look up the data sheets for them, to get a better clue, sometimes you can also find application notes where they may have a circuit similar to the one you are working on...

That does look to be a simple circuit, most ultrasonic cleaners amplifier circuits are normally much more complicated.

I love Irons solutions to a problem, his idea was good medicine for me, (laughing until my stomach hurt).


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## ericrm (Sep 18, 2014)

butcher said:


> How many ceramic crystals were driven from that board?


8 or 10 maybe 12... im not sure right now

thanks for the help


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## ericrm (Sep 18, 2014)

i think its 12 motor and i have been smart (lucky) to think of sniping the wire without removing them from the second board
so white with white black with black green is ground. and 2 little dots seem to indicate where the motor were plugged... can i safely put 110 on that board just like that whitout risking burning something?


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## Barren Realms 007 (Sep 18, 2014)

ericrm said:


> i think its 12 motor and i have been smart (lucky) to think of sniping the wire without removing them from the second board
> so white with white black with black green is ground. and 2 little dots seem to indicate where the motor were plugged... can i safely put 110 on that board just like that whitout risking burning something?



You need to find out what the line side of the transformer is and what the load side is. See if you can do a search of the mfg. and see if there is a wiring diagram of the board maybe available.


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## Long Shot (Sep 18, 2014)

Irons - You are awesome! George Jones tried that unsuccessfully me thinks!


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## butcher (Sep 19, 2014)

The two sets of terminal blocks on the left do look like 110 VAC, at least one will most likely be the input, black hot (ungrounded), white neutral (grounded). and green ground (grounding).

With the color of these wires, and the L1 and L2 fuses next to this terminal block,
(one of these fuses probably go to the black and one to the white) the black may go through the inductor, maybe a capacitor before going to the primary of one of the transformers.

At least one set of these sure looks to be the 110volt input, you would not have need for two inputs to power the board.
The other set could be a switched output, With there being two sets of these, the other may not be an input, or it could just be a connection (jumper block connection on the board),that fed the input to some other board or even from a switch to turn this board on and off... 
you can see if both are tied together with traces, (are both sets of terminals with the black wires tied together, whites together, and greens together, if each of color are not tied together (one leg may be switched on the board), (or could have gone to a switch that switch power back to this board), if you cannot see the traces you can use an ohm meter (in ohms scale to check for continuity). or a light bulb and battery.

An old flash light can be used for this tool, (to check for continuity, just put wires to each side of the flash light switch, and use them for test leads.

Are there traces on the back side of the board, seeing both sides can be helpful, also seeing or knowing the numbers or letters next to the terminal blocks, and circuit components are clues to what they are or what they may be for.

If this is the driver for the crystals, my guess is the transformer without the white insulators is the power transformer (to lower the voltage to the circuit board which is then rectified to DC for the board). 
The transformer with the insulators my guess is was what drove the crystals at the high frequency, the blue wire may be a feed back loop to its driver circuit.

The transistors (or whatever), with the common heat sink on the end of the board, these could be the driver circuit for the high frequency transformer (along with its large ceramic resistors and capacitors).

With the simplicity of this circuit, we may be able to find a circuit similar to this from looking at driving ultrasonic transducers, searching through this type of circuit on the internet...
something like this:


https://www.google.com/search?q=ultrasonic+cleaner+circuits&newwindow=1&source=lnms&tbm=isch&sa=X&ei=IbYbVP2EJ6SLjAKKrIHoDw&ved=0CAkQ_AUoAg&biw=626&bih=396&dpr=1.25#imgdii=_


You speak of a motor, was there a motor? or are you calling the crystals motors?

Was this the only circuit board in the ultrasonic cleaner? was it an ultrasonic cleaner?
Do you have a manufacturer or model number of the machine these came from where we may be able to find a schematic, or more information? 

As far as trying to power up the board and seeing if it will work, I would probably try it, after doing some tracing of the circuit, to get a better idea of it, and after trying to find more information like schematics...

I would not recommend it, if your not used to working with electricity, or circuit boards.


The terminal outputs may just be hot wires of the crystals, the grounds for the crystals may just go to the heat sink it looks like there is a terminal connection there.

Your pictures are helpful but without having the board it is hard to tell much.


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## jason_recliner (Sep 19, 2014)

The terminal blocks at the fuses are your AC input. We can easily see where they are filtered and rectified by the four diodes to produce a rudimentary 155 Volt DC line. The whole board runs at 155V DC.

From there, the exact method used gets a bit hazy without being able to see all the copper traces around the four transistors. They may well drive the transformer T2 (C3003305) in a full bridge. Simply put, this method effectively doubles the voltage available on the transformer.

T2 does not reduce the voltage to the board. In fact it's not suitable for 50/60Hz operation at all. And it may or may not reduce the voltage to the transducer. But its job is to take the 155VDC, as driven by the four transistors, and produce a high frequency AC. This will happen at probably [Edit: 30-80KHz]. I can't see exactly how the timing is controlled, unless L2 has something to do with it. Seeing the copper traces better would help.

The transformer C3033402 with the spacers: (I can't see a marked name for it, possibly L1 as the four-turn air cored inductor in the middle is marked L2. Or there may be a T3 written somewhere.) This looks like an inductor, not a transformer, though the 2 turn blue wires will provide some feedback. It will work with C12, C13 capacitors. The spacers prevent the ferrite core from saturating with magnetic flux. We don't do that with transformers. It will be driven hard, and I find it interesting that they appear to have used soft material (variable thickness) as core spacing.

The output from this inductor will lead directly to the ultrasonic transducer.


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## ericrm (Sep 19, 2014)

butcher said:
 

> You speak of a motor, was there a motor? or are you calling the crystals motors?


yes i call them motor because i dont know what crystal are...
I would not recommend it, if your not used to working with electricity, or circuit boards.
[/quote]
i not realy gifted with electricity like you and so much poeple here


butcher said:


> Was this the only circuit board in the ultrasonic cleaner? was it an ultrasonic cleaner?
> Do you have a manufacturer or model number of the machine these came from where we may be able to find a schematic, or more information?


no it wasent the only board ,but it was the closer board that connected to the crystal 
yes it was an ultrasonic cleaner
no i dont have any model info anymore 

i will find the crystal and edit my post later but if i rember corectly i think butcher you nailed it.


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## butcher (Sep 19, 2014)

I am not that familiar with this type of driver circuit, it does sound like jason_recliner has more experience in this area.


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## ericrm (Sep 19, 2014)

im not sure why but i completely missed his post... thanks
i now know were all the wire go ...
jason_recliner, do you think it would be ok to plug this board strait on 110v from the house electricity?


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## jason_recliner (Sep 19, 2014)

It does appear to run straight on 110VAC. It certainly is expecting a mains input. We know this from the four rectifier diodes to convert from AC to DC, the common mode toroidal choke to reduce line noise, and the varistor (little blue disc) to eliminate short spike voltages. And it's labelled 110V.

If there were other boards, it's _ possible _that one of them is meant to provide a clock input; that is, the timing pulse that triggers the transistors to drive at a particular frequency. On the other hand, if timing was controlled by an external board (unusual practice anyway) and it were low voltage logic circuitry, there's no obvious safety isolation here. So I'd discount it. It's probably that this board self oscillates on one of those capacitor/inductor pairs in the centre, though I can't see exactly how timing is controlled. 

Piezo devices are more voltage oriented than current, so they are probably all wired to the output in parallel. [Edit: Looking at your last photo, I can see they already are.]


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## ericrm (Sep 19, 2014)

yes they are all in parallel. only thing left is to try it. thanks you jason_recliner


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## butcher (Sep 20, 2014)

When giving it the smoke test, stand back when you plug it in :lol:


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## jason_recliner (Sep 20, 2014)

Keep in mind that if these transducers are running at dogs-and-cats-only frequency, you may not be able to see or hear anything happen.


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