Hi, guys welcome to Electrical Project channel.
Today I am going to build version 2.0 of my magnetic levitation device.
Previous version was unstable and required a power supply with adjustable voltage,
which is not good.
So, I did some experimenting and came up with this circuit.
Testing showed good results, so I decided to make a complete device.
By complete I mean to implement it on a PCB, and make a frame for the device.
Well here is the PCB that I created in KiCAD, it is my first KiCAD project,
but I hope it'll work fine.
This is how the completed PCB should look like.
I am going to make the PCB at home, which is a little challenging, but doable.
I did it before but it was a long time ago.
Well, let’s do it.
The first step is to print the PCB layout.
Now we need to transfer it to a copper-clad board.
I need to align it properly.
Now we need to apply some heat.
The next step is to remove the paper.
I need to remove the paper without removing the toner.
This is not the only way to make PCBs at home, I remember using photoresist to make pretty
complicated PCBs, with good quality, but it was a long time ago, and I don’t
have photoresist now, so I’ll try this simpler method.
There are still present micro fibbers from the paper, I need to remove them.
Now it is time for etching process using iron chloride.
And after some time copper that is not covered with toner disappears.
Now after etching finished I got this.
Let’s, clean it.
And here is the result.
Well, it is not perfect, seems like iron chloride got trough the tonner.
Well, it is not perfect but still usable.
Ok, here goes the next step, The next step is simple, I need to drill holes.
So let’s do it.
And here goes the fun part of the project, it‘s the assembly of electronic components
to the PCB.
I going to start with the heat sink.
Heat sink dissipates a lot of heat, so I use 60W soldering iron, to solder it properly.
For other components, I am using my regular soldering iron.
Next, I decided to solder MOSFET.
But it is pretty arbitrary.
Now let’s solder, Trimmer Potentiometer.
And now let’s solder electrolytic capacitor.
Polarity is important here, so pay attention to polarity markings.
When it is done let’s solder the diode.
Polarity is important here as well,
Cathode needs to be soldered to the positive trace on PCB.
Now let’s solder the LED, Longer lead is anode lead.
Anode later will be connected via SMD resistor to the positive retrace on the PCB.
Now let’s solder TL431, Looking at TL431 electronic symbol some may
think that it is some kind of weird Zener diode, but it is actually just an integrated circuit.
TL431 is commonly used in power supplies.
Now lets solder 78L05 with is 5 volt voltage regulator.
And when it is done, let’s solder jumper wire.
And now it is time to solder SMD components.
Let’s solder 1K resistor that connects LED to the positive PCB trace.
Now, one more 1K resistor.
And here goes 100nF capacitor.
1K resistor again.
And now 1uF capacitor.
Ok, now I am going to solder two of the 330K resistors,
they are connected sequentially so together they make 660K resistance,
you can, of course, try to use a little bit different values,
but I experimentally found out that values about 600K work well.
Ok, now it is time to solder wires.
There is not much to explain here, two wires needed for power,
and two wires will be connected to the electromagnet.
Also, we need three thinner wires that will be connected to the Hall Effect sensor.
And that is it.
Also, I use hot glue, so bending does not damage the wires.
Now let’s clean the PCB.
And now I realized that I forgot to solder 1uF capacitor,
well this capacitor is not that important, but let's solder it.
Now let’s clean it.
Now I covered the PCB with old expired photoresist spray,
it will work as a protection layer, you can use nail polish instead,
transparent nail polish should look even cooler.
But I use what I have.
Also, I decided to apply the thermal paste between the MOSFET and heat sink.
It is not necessary, but it potentially should make things better so let's do it.
Perfection is not attainable, but we can try.
Now let's make a small PCB for Hall Effect sensor.
I need to cut copper layer into three different pieces.
Now I going to salvage Hall Effect sensor from old floppy disk reader’s PCB.
But you can also find them in motors of CD/DVD drives.
Now let’s solder Hall Effect sensor to the PCB.
And now let’s solder wires.
The black wire we need to conned to the bottom,
on the main PCB black wire is connected to the ground plane.
Now let’s connect the red wire to the top right square.
On the main PCB red wire is connected to the 1K SMD resistor.
And let’s connect the blue wire to the top left square.
On the main PCB blue wire is connected to 10K trimmer potentiometer.
Now let’s clean the PCB.
And that is it; you can even do some tests now.
By adjusting potentiometer you can change the sensitivity.
Now let me show you specs of the electromagnet I am going to use.
I did not make this coil; I’ve got it from some device.
It is 31 Ohms, 58mH.
Now you need to tune the device, you need to adjust potentiometer in way so
LED turns off when you bring the magnet close to the sensor.
Now when LED is on bring the magnet to the electromagnet,
you should feel attraction, not repulsion, if you feel any repulsion, it means you connected
electromagnet with the wrong polarity, so you need to reversed the polarity.
Now let’s test it.
Well, it kind of works.
Also, I recommend covering the hall sensor's PCB with Hot glue,
Because sometimes the magnet hits the sensor and can damage it.
Now I need to mount PCB to the frame.
So I need to drill holes in the PCB, I should have thought about it before.
But let’s do it now.
Also, I drilled holes in the frame, so let's mount the PCB.
These screws are overkill here, but again I use what I have.
Ok, the PCB is mounted now so let’s continue building the frame.
You can come up with a completely different frame idea, this is just an idea that I came up with.
You can of course use this device without any frame at all,
you’ll just need to hang electromagnet somewhere.
It is all up to you.
Well there is not much to comment here, so enjoy me not talking!
Also, there is should be some space between the electromagnet and the hall effect sensor,
otherwise it will not work.
You can use some plastic or something similar.
The device can work in a wide range of voltages, from 8 volts up to 16 volts,
16 volts is the limit just because I’ve used 16V electrolytic capacitor.
I think 12V is the perfect choice for this device.
I’ll use a 12V DC power supply for powering, such power supplies usually used with routers,
so it is easy to find one.
It can even levitate my wire cutters,
so it probably could work as some fancy advertising setup.
And that is all, thanks for watching!
Don’t forget to like and subscribe, and see you in another one!