Ultrasonic bath

The transducer is probably highly resonant at the operating frequency. If you change the frequency, output is likely to be greatly reduced.

'it' being frequency? If so, I doubt it: the transducer is resonate and would have to be replaced.

'it' being power? If so, I doubt it: the transucer is only going to be able to handle a certain amount of power before failing.

I don't think the transducer is so high resonant. At least the specific one. On the other hand, I would like to try. Do you know which parts to change?

Just to say what I meant. The specific transducer is inexpencive one, most like a "buzzer" than a conventional transducer. I have seen some other ultrasonic baths involving just a buzzer!! I don't care for the power, even if it reduced at 10%.

one.

I'm going to be nasty. What needs changing is your attitude.

Why are you wasting our time? You haven't supplied a manufacturer or a model number, or a place to find a schematic. Why do you think anyone would have the knowledge to suggest a specific change for an unknown product?

Furthermore, the answers I and others gave were "reasonable" in the context of the question you asked and the overall design of such products.

If you know so much about the unit, modify it yourself.

To be a bit more diplomatic :), the OP did supply photos of the PCB.

But, someone would have to take a fair amount of time to try to figure out which parts control frequency from looking at it. "Blue caps" don't mean anything - one has to trace the circuit to determine what the components do.

If the OP would do that and post a schematic, or even a partial schematic, then someone should be able to help.

-- sam | Sci.Electronics.Repair FAQ:

Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs.

Your first three words are correct. The remainder of the statement is not. It is very resonant.

Horse... Dead... Beating... Stop!

Thank you for your reply.

You are right. I tried to find the schematic on internet with no luck. If I try to trace the schematic it will take much time, because I don't have much knowledge in electronics, none in oscillators. For me, it will take two days... I'm sure, you know, someone without knowledge may needs 20 or 50 times more time and effort to find what he wants. If you could guide me to trace a very small part, I will. The model is the CD-2800, CODYSON (China) is the manufacturer. The only info I found on internet are the following. I don't know Russian, I tried to register but it has a quiz of 15 questions:

p.s. If the above forum has the schematic, may it worth to find it first.

-- Yianni

On Thu, 14 Aug 2008 17:49:17 +0300, "Yianni" put finger to keyboard and composed:

Is there is a patent reference on the label? If so, then you can sometimes find a how-it-works explanation at ...

Here are some examples:

OSCILLATOR CIRCUIT FOR AN ULTRASONIC CLEANER

If you read the text of the various inventions, it appears that they all use a 40kHz piezoelectric transducer driven by a two-transistor oscillator. One patent states that "the oscillation frequency is dependent mainly upon the characteristics of the piezo element". I think what you are trying to do is akin to changing the natural oscillation frequency of a quartz crystal by playing around with external components, ie it makes no sense.

- Franc Zabkar

Yeah, I despise those sites..... Although in all fairness, some have useful information or downloads.

Whether they have a schematic? Could be, but it could just be someone else asking....

There's probably a pair of power transistors or MOSFETs that's a power oscillator. If you trace around that area, it could help. But no guarantees. But assuming it is resonant, that may be part of what determines the frequency.

-- sam | Sci.Electronics.Repair FAQ:

Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs.

Well, he could go lower by adding mass to it. Higher? Chip off a piece? :)

-- sam | Sci.Electronics.Repair FAQ:

Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs.

What are you ``ultrasonicing`` ? With todays good cleaning products i use my ultrasonic way less these days

Particularly if it's an inexpensive product. It would make sense to have the circuit oscillate at the natural frequency of the transducer.

On 14 Aug 2008 19:30:19 -0400, snipped-for-privacy@seas.upenn.edu (Samuel M. Goldwasser) put finger to keyboard and composed:

In all honesty, I was going to suggest something along those lines, assuming it is at all feasible. Years ago I had a problem with a 25MHz crystal that had begun to oscillate at a higher frequency (not an overtone). I suspect that either a piece had chipped off as a result of an accident, or maybe a dag that was present during the trimming process finally fell off in normal usage.

Alternatively, the OP might try procuring a ready-made replacement:

For example, the ANN-2560 is rated at 59kHz and 25W.

- Franc Zabkar

WHY do you want to increase the frequency?

Dave W

We don't even know what he wants to do with it. Maybe for somniluminescence or cold fusion! :)

-- sam | Sci.Electronics.Repair FAQ:

Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs.

The higher the frequency the less cleaning power. But... in higher frequencies, the cleaning power it reaches to smaller cavities, etc (for parts with holes, etc). I want to do a test for specific parts.

On Thu, 14 Aug 2008 04:41:23 +0300, "Yianni" put finger to keyboard and composed:

I don't know if this will be relevant to a 40kHz transducer being driven at 60kHz (if that's possible), but the 59kHz transducer in the following product range has a rated power of 25W whereas the 40kHz transducer with the same impedance is rated for 40W.

BTW, on closer examination of the circuit, it appears to me that the LM555 is switching a relay which in turn switches rectified but unfiltered mains voltage to the oscillator. I suspect that the piezo element determines the frequency of oscillation, and this oscillation appears to be amplitude modulated by the 120Hz/100Hz mains.

- Franc Zabkar