What’s up my friends, welcome back.
THis here is a huge capacitor.
Well, it is not really a capacitor, it only has the shape of one.
This is actually an ultrasonic mist generator.
A few weeks ago I saw a post on twitter with this picture.
It looks like the magic smoke is coming out of a huge capacitor.
I thought that was a great idea but I couldn’t find this product to buy so I've made one
myself.
Usually, we use these moisturizers with perfume in order to increase moisture of the air and
also create a nice smell.
We add any perfume such as this one here and when the mist is created it creates a nice
smell.
You can buy such moisturizer online but I couldn’t find one with the shape of a smoking
capacitor which is a great idea.
So let me show you what we need, the 3D design of this case and how to assemble it.
Finally, we will see if this project works ok or not.
So, let’s get started.
What’s up my friends, welcome back.
The most important part for this project is the 3D printed case.
That’s because the electronics part is very easy and is very important to have a good
shape of a capacitor in order to look good.
My design of the case is made out of 6 parts and in a moment you will see why we need so
many parts.
This is the container where the water will go.
This is where the mist maker module will go and the rest of the electronics and we can
close this part using this other one and this will have the ventilator.
Then we have the main cover of the capacitor which already has the numbers on it.
All we have to do is to paint it with a different color.
We also have this lid that will go on top and be painted silver in order to simulate
the top lid of a capacitor.
Finally, we have these feet so the entire capacitor will have some space from the ground
and air could flow.
So, let’s prepare the parts and paint them.
I’ve printed them all with PLA material, 2 perimeters and 20% infill.
You might need to sandpaper them a little bit so they would be smoother.
Remove all loose filaments or unwanted plastic parts.
Now let’s paint them.
Electrolytic capacitors have all sorts of colors.
Usually they are black, brown, green or blue.
I wanted blue but I didn't find a good blue color, that’s why I will make it brown and
the text will be white.
I paint all the parts with spray paint.
I apply a few layers.
This part will go inside so it is not important to paint it.
The lid will be silver and the outer part of the case brown.
Then we will paint the details with black or white.
Leave the paint to dry and thill then let’s go over the part list for the electronics.
To generate water mist we use this high frequency ultrasonic piezo.
This component vibrates so fast that it pulverizes the water into very fine mist.
This module here works at 5V, and if you remember, I’ve used it with the 3D printed halloween
pumpkin project.
But that wasn’t that powerful so in order to get more mist and make this project cooler,
I will use this other module that works at 24V.
This can create a lot more mist as you can see here.
Best of all, it is already water sealed and it has a low water level protection.
When there is no more water, so no more connection between this metal pin and the generator,
it will automatically stop.
That’s great because without water this generator would crack and not work anymore.
To supply the generator and the rest of the electronics I will use a DC adaptor like this
one of 24V.
To connect it to the entire device I will use a power jack like this one.
The digital control will be made with an Arduino and to control the time and the power I will
use 3 buttons.
I want to use these capacitive buttons instead of normal push buttons.
I will also add a buzzer for sound notifications.
To get 5V out of the 24V supply I will use a buck converter module like this one.
All you have to do is to solder the 5V connection on the back.
By the way, you can buy such modules from my shop.
Links are below.
We also need a fan to push the air upwards and carry the mist to the hole on top.
But because this is a 12V fan and the supply is 24V, I will set the buck converter to 12V
and supply the Arduino directly on the Vin pin.
To control power applied to the fan and mist generator, I will use some N channel MOSFETs.
We will also need glue, some resin in order to water seal the container, screws, threaded
insertions, wires and some other tools.
You will have the full part list below.
By now the brown color should be dry.
Is time to paint the details.
We can use black or white for this job.
An electrolytic capacitor must have a line marking the negative pin so we pain that line
with a different color.
Then we paint the text for the uF and voltage and that’s it.
In my case I’ve used a white permanent marker for the text.
For the line I’ve used spray paint but I’ve covered the rest of the case.
Now the case is ready and we know what we need.
The schematic for this project is this one.
The Arduino will control when the fan and the generator are powered on using a timer.
To control that we have 3 buttons but we might only use 2 of them.
Before we make any connection we first have to water seal this part using resin and let
it dry because it will take a few hours.
I mix two part resin.
Then I apply a layer inside the 3D printed part with a brush.
Then we let it dry and we can continue with the rest.
I get the other 3D printed part and we add some threaded insertions.
As always, we heat them up with the soldering iron and push them inside the plastic.
Now we can use screws to close the bottom part.
Then we have to remove some plastic from the mist generator.
Otherwise it won’t fit inside the 3D printed case.
So we make it flat and now it should fit perfectly.
At this point, we can use some glue and fix the generator inside of the printed case.
Next I solder some wires for signal and power to the buttons.
Now I have 3 buttons in series with 3 wires for signal.
Then we can glue them inside of the other bottom part of the case, just in front of
the buttons circles.
Then we should supply 5V and check if the sensor can detect our finger or not since
the plastic might be too thick.
But no, it works perfectly.
Now that we have the buttons, the next part was to add the power jack.
Fix it in place and next we add the on and off switch on the side.
We add wires for ground and 24V and connect them between the jack and the switch.
At this point we should add that buck converter but I’ve realized that the maximum voltage
of that module is 24V so since my DC adaptor is a bit above that, it would burn the converter.
So I’ve made a small linear converter with the LM317 IC.
I solder this converter to the switch and now we can get those 12V out of the 24 supply.
I glue the converter inside the bottom case.
By the way, we should add the fan and using some screws we fix it in place as well.
Make sure it pulls the air in and not blow it out.
To control the power for the fan and mist generator I’ve made a small PCB with a MOSFET
and a BJT transistor as a gate driver.
This would have a connection to ground, 12V for the BJT and signal.
Check the schematic for more.
Y connect this to the fan and glue it in place inside of the 3D printed case.
Then I make another one for the mist generator but this would work at 24V.
I connect it to some female pins and glue it inside the case as well.
And using those female pins we can connect later the upper part that has the mist generator.
Now is the time to connect all these wires from the buttons and the MOSFEts to the Arduino.
So I take each one and connect them to the digital pins and also supply 12V to the Arduino
from the regulator.
Everything is now connected.
By now the other part with the resin should be dry.
So we have to place it on top and make sure it is water sealed.
We add 3 screws and we tight them from below with some nuts.
Then I make some more two element epoxy and I place it all around the mist generator module.
Also, we add some more epoxy over the screws in order to make this entire container water
sealed.
So now, finally, everything is dry and ready to go.
We can connect the mist generator to the bottom case with the electronics.
Then we can also glue in place that silver part on top of the capacitor and from the
inside.
Now it looks a lot more like a capacitor.
Is time to upload the code so download it from below.
The code is very easy.
We detect when the button is pressed and we change the mode from 0 to 4.
Each of the modes 1, 2, 3 and 4 are for 15 minutes, 30, 45 and 1 hour time of mist generation.
To let the user know which mode is selected, we make a beep, 2 beeps, 3 and 4 beeps and
a long beep when the generator is off.
This is an example of how it works.
When the mode is not 0, we use digital write to turn on the fan and the generator MOSFETs.
And when the mode is 0, we turn them off.
We count time in seconds and when the elapsed time is higher than 900 for example in case
of 15 minutes, we jump to mode 0 where we turn everything off.
That’s it for the code.
Once uploaded give it a test and see if it works so connect 24V and test the buttons
and if the fan turns on.
Now the resin is dry and the container is water sealed.
When we merge together these parts, the idea is that the air from the fan will go upwards
through this hole and it will push the mist upwards as well and it will exit through the
top hole.
Without the fan the mist will just stay inside.
I place some paper towels below and add water.
I check if there are any water leaks but everything seems to be ok.
Before I close the case, I connect power and give it another test but this time with the
generator connected and with water.
It works very well and creates a lot of mist.
Now I close the bottom case.
Then I add water again and place the capacitor case on top.
Looks quite good, right?
I connect power and turn it on and there you go.
It can create a lot of mist and it really looks like a magic smoke capacitor.
I can say the project is a success.
The idea is to add perfume to the water and give a good smell to your home.
For example, I bought this mist generator a few years ago and it comes with all sort
of perfumes for the water.
Just a few drops and it will give a very nice odor to the water mist.
So this project is cool but is useful as well.
I had to change the design since the water container is too short and some water will
get spilled out.
I should make this part taller.
In the final design I’ve made the container taller but I’ve also added a skirt around
this container so any water spill would go back inside.
I also realized that I’ve made an error by placing the power jack below.
Is too high so the legs that I’ve printed won’t be enough.
I think it would be better to have the power jack on the side together with the switch.
Anyway, you have all these changes below with the final design.
So make sure you download the schematic, the 3D files, the code and the part list from
electronoobs.com I hope that you like this project and maybe you’ve learned something
new.
If so, give me a like or comment below.
Thanks again and see you later guys.