eBay atomiser module test (with schematic)

A look at a very common little atomiser module sold on eBay. This style of circuit is often found in the USB powered desktop humidifiers that use a wick and piezo disk to put a visual stream of moisture into the air.

This is a very minimalist circuit, which makes it very interesting. There's no feedback, so the microcontroller is just banging out a rough 110kHz to the 16mm piezo disk.

I really went to town on reverse engineering this module, including desoldering and measuring all the capacitors, and unwinding the little transformer to count the windings and measure the wire diameter.

To find these on eBay search for - usb humidifier module
It's often cheaper to buy a multipack, plus that gives you spares.

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#ElectronicsCreators

[EngineeringMindset]

Interesting video, hopefully it can calm my urge to dismantle the new Essential Oil Diffuser in the hallway... for now.

[Pendentive]

I have been watching your videos for close to 2 years now. I have slowly googled the electrical circut terms, and then again when I couldn't remember. As well as trying to keep up with the math, I have luckily always loved math so that came easier than not, I have been slowly getting the concepts down about current flow and circuit logic.

I recently caved and forced myself to get a nodemcu 8266, a pi pico, then eventually a mega. With leds, and simple things so far as circuts go, but pushing the code.

But today, I looked at the circut board and started to see the diagram before you drew it. I understood what the purpose of curtain components was better than before, and things just clicked. Obviously not perfectly, but more so than before.

I can't thank you enough for your diligence and dedication to your craft. I appreciate it.

[MrBunl]

Interesting device. It's a tapped inductor as opposed to a transformer. The output is probably much greater than 30V but will depend on the load.

[penitentiarychances]

Thanks so much BigClive! Videos like these are so helpful, in fact, the thing that led me to this channel was your past video about the deadly camping light, I had just purchased it and was watching reviews. I saw your video and was horrified. That thing has probably burned peoples homes down. So I watch every video just to be aware of these sketchy products. They even fill batteries with sand and put them in powerbanks. Thanks Clive, you possibly saved me from burning down my home.

[ATMAtim]

Funny to see this video highlighted. I'm working on a fogger for my daughters Hermit Crab habitat to raise the humidity. It was good to see you working with one.

[rexsceleratorum]

Appreciate the thorough reversing, the sacrifice of that board is not in vain

[DLLdll]

Thanks for all you do.
One additional point on your circuit analysis. I believe the capacitance of the piezoelectric material and the inductance of the transformer secondary winding form a parallel resonate circuit. Giving an additional increase in voltage when driven at the resonate frequency of 110khz. Typically these piezoelectric nebulizers are drive to 80 to120vpp. If you use a dvm (set to AC) across the piezoelectric device you can determine if this is the case.
Doug Lewis

[byronwatkins]

At 6:30, possibly the LC resonance amplifies the effect by another factor of Q if the piezo's capacitance is tuned to match the coils' inductance -- self plus mutual.

[richardhalliday]

I have used these for a couple of years now they work quite well, unfortunately they tend to self destruct necessitating in a repair or replacement ( usually the piezo) as I run them with a few drops of Zaflora added to humidify the air with a fragrance but the liquid tends to contaminate and bung up the piezo. Cheap enough to replace though.

[zh]

In my 1970s childhood if you had a model railway and you wanted the engines to produce scale "steam" there was an unsatisfactory system for having them emit electrically produced smoke instead by using a heating element in oil. You can see it in early episodes of the Thomas the Tank Engine TV series. These clouds of microdroplets look a lot more like steam, and would be 100% safe, non-toxic and easy to refill. I wonder if anyone has fitted them to a model engine?

[designedbyheinz.ginkulmwes]

Working on a project with piezo atomizers! This was a crazy good shortcut. Thank you very much! Greetings from Munich!

[DavidFenner-pz]

Many thanks for demystifying. Out of interest, a scope reading of a similar device showed 152v p/p at the piezo. Conversely a home brew using 555 and 12 v supply gave about 50v p/p so less effective.

[thalesmaurin]

Thank you for this incredibly informative video! I'd never seen videos whit this kind of schematics. I appreciate the time and effort you put into creating such valuable content. Keep up the fantastic work!

[yaidontknowwhattoput]

That technique of ac driving a MOSFET is a nice way to prevent run away if the uC locks up as you said.

[commanderofthewind]

Wow Clive, you really do have a video for every topic. I was wondering if there would be a way to lock the control board onto one mode, possibly just with a jumper over the ICU. Would this be possible? Thanks

[So-Now]

The processor pinout looks like a PIC10F200.
I measured a peak of about 160 volts on the output whilst trying to identify the inductor.
Pressing your finger on the output pins without the transducer connected, yields a satisfactory tingle.
The circuit also works well for the copper foil type slug repellant.

[Shaun.Stephens]

Thank you Clive, especially as you've entertained me but not prompted me to buy multiples of the unit. :)

[carlfranz]

I got one in my garage that, i believe, is 240v three-phase but it's designed to remove cutting oil from brass and has heaters

[rexrodecolt]

Wow I'm actually picking up more and more learning from your videos for my hobby. You are the man! Thank's again for the reply to my silly question lol Very Interesting Video!! A quite odd little piece of machinery in a way.

[augustopizarro]

Excelente! I bought one to make a Dragons Breath, do you think it is possible to couple a transistor to the MOSFET to drive some leds?