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I wanted to do this Electrical Firefly Lantern for a long time! FINALLY DONE with my wireless fireflies!!
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By: Mehdi Sadaghdar
0:00 Describing the Firefly Lantern Project
1:19 Wireless Powered Fireflies Design
4:26 Wireless Power Driver Circuit (ZVS) Design
5:51 Lantern Mechanical Parts Design and Print Them with My LulzBot
8:28 Making the Fireflies Fly, the Aerodynamic Designs and Issues
12:41 Building the Wireless Power Driver Circuit (ZVS)
15:09 Firefly Lantern Assembly and Demo
17:46 Keysight World: Live from the Lab Event and Giveaways

Hi today I'll design and make something incredible. a lantern. No, no wait, got a crap. Lantern A magical Fairyland Lantern one of those that are filled with fireflies and glow.

What did I show there? The final product. Did I make it? Uh, we don't have fireflies around here. so I'll make electronic fireflies and I want my fireflies to actually fly. so I'm not gonna buy some Ikea LEDs on a string and slap them in a jar and call it a firefly.

Lantern and I can't power them by hanging them from wires because they'll move around and Tangle to each other. so I'll have to power them wirelessly. Let me show you, it is basically like a Transformer with the primary and secondary coil and I connected an LED to my secondary. and if I raise the voltage to the primary from my auto.

Transformer you can see that melts the out of the primary. You know they say inductors block AC No, they limit AC You know if someone drops you on the sun, closing your eyelids won't save your eyes. Such small inductors need to run at much higher frequency like 100 kilohertz or more. Let Me Explain The Plan: Basically my fireflies have an inductor and capacitor that resonate at a specific frequency excited by the fields from some bigger transmitter coil running at the same resonance frequency.

So the voltage across the resonance circuit Rises to a point that can turn on an LED across it. How do my fireflies fly? I'm thinking I'll just put a fan under them and blow on them to you know, lift them up so they have to be light. Let's make them. This is the primary of a wall adapter Transformer I Salvaged a while back that has this very thin light wire suitable for my flies.

Does it look super pretty? Let's see if it works. So so I bought two LEDs to try that you may not see here. This one is yellow green which is very similar to the color of a firefly, but it's dim. This one is just warm white but much much brighter than the other one.

I may try both and see what happens. Now the question is if I can solder this tiny capacitor to this tiny LED By the way, my sponsored Keysight is sponsoring this sponsor segment Because they're not done, they'll have more events this year teaching electronic tips and tricks and giving away tons more of these. Heavenly Tools watch to the end or the link in the description for more details now. I provide a 50 Kilohertz signal from the function generator of my scope to some random coil I Have here if I place that around my tiny coil here.

Ah, it doesn't turn on. Nope. Hi I'm Captain Hindsight, my friend. simply call me.

Bless you, shut up, let me save you the headache. I have like two months worth of footage of testing and failing you don't want to see. I Tested this a bunch and realized you can't make the same inductance if you increase the diameter of the coil and reduce the number of turns. But bigger coil means more magnetic fields pass through it and so more energy is transferred.

Well, as long as the coil size is smaller than the coil inducing the energy. Remember, the fields have to close around the wires not inside or outside. So I tried a bigger coil and even bigger which helped, but then the weight was a problem too. Change of plans: I can't keep increasing the number of turns on the coil.
it will get very heavy and won't be able to fly. So instead I decided to go to a wider coil with only a few number of turns, six and a half turns, and whatever the resonance free frequency of this circuit will be. I'll tune my transmitter to match this. Okay, here we are and I mounted the coil on a thin plastic sheet too so it doesn't deform and we have the capacitor and dial.

Let's see. Oh, look at that. Let's find the resonance. Whoa! Okay, so I say the resonance is around 95 kilohertz so that's what we'll design for Now to make the Lantern First things first: I buy a proper size glass because this is the one thing I can't make myself and I'll design the lantern around it and to transfer the energy, I'll put one coil on the bottom and another coil on the top.

These two coils will have the same direction of winding, so same direction of magnetic fields. And with these, I'm hoping to create more uniform fields around the center of the glass. But depending on the location of my fireflies, they could see more or less Fields so brighter or dimmer. And also depending on their Direction, they could turn on and off, which is fine.

It's like fireflies flying around blinking. Let's talk about the driving circuit. I'm using my beloved my stable asynchronous zero Volt Crossing oscillator circuit that I used in my previous videos too. In this variation, I added a current limiting circuit to ensure safe startup and operation.

Also, these two inductors are the ones that go on each side of the glass. I'll run it from a 12 to 14 Volt Supply So I would have close to 40 volts Peach across the two inductors. So far I didn't have enough voltage to turn the LEDs on, but that must be enough. But first, I Have to finish the mechanical design so I can fit my circuit to it.

So here you see my glass with two coil holders on its top and bottom. Let's print it on. print my parts using a gray filaments and look how well the glass fits in it. Nice! Now let's design the rest of the Lantern First, I Bought this fan with a diameter which fits the glass well which I'm showing by this black thing on the bottom.

Then I designed this beautiful leg so the coil holder Falls right into it and the fan on its bottom. Let me show you a bit more details. see: I designed these fins in there because you know the fan rotating creates a Vortex inside the glass and I didn't want my fireflies to stick to the sides of the glass so I put it in there to hopefully straighten the airflow so that they would fly more nicely in there. then at the bottom of the fan I designed this grid so that you don't stick your fingers in the blades.
Next on the top I designed this vent. Now this vents might be tough to print, but anyway I created the same fins to help the straight airflow and a curved ceiling there to help push the air out from the sides. and then on the top up comes a beautiful cap. Now this cap has a cavity in there which is the location for my driver circuit.

And last but not the least, I'll hold all the pieces together with these screw rods. Beautiful. isn't it? See, even a monkey can do a mechanical engineer's job. Nope.

The monkey couldn't do it in one shot though. All the parts I designed had to be updated and I had a bunch of difficulty printing my parts because of the lack of 3D printing skills I Had to trash a lot of parts with incorrect designs I kept greeting my parts and had to re-glue redesign reprint. Oh probably just crazy glue. this just need some.

Why do I have to have the Prince in the meantime? I started making the four rods that would hold the whole thing together out of Some solid brass rod. Having these wasn't easy man. I Feel hurt and bruised. Time to design my fireflies? Something that can fly Hi today I'm having aerodynamic problems.

see I've been messing with the shape of this fly thingy trying to make it jump up and down in this chamber. but see I thought the fan blows from the bottom and this thing will go up and down like a fly. but no, the air pressure is not uniform in there. It's like higher pressure in the middle, lower pressure on the surface.

so it goes up in the middle and gets stuck on the walls. and if it goes all the way and reaches the fins back there, a high pressure air builds up behind it that makes it get stuck up there and never comes down. Let me ball some papers and see. Oh see they go get stuck up there because of the high pressure behind them.

Well it does seem bowling it has a better chance of rising here here. I made it kind of bullish like come on, come on. Oh oh look at that. it's flying, not bugs get stuck up there.

Still it seems removing those air straightening blades and let it just cyclone solves almost all the problems. Also, making the Firefly like a ball makes sure it doesn't stick because it can roll around easier. So I guess we'll cut these fins off to allow the vortex. There we are.

But then I had to make a mesh to make sure my fireflies don't fall into the fan blades and die which I try to hand print on the 3D printer hot plate. The properly printed part worked better in an attempt to go glueless to make my flies lighter. I came up with this which looks nicer too. Now we have to slide this piece on top of our old piece and just make sure they're notches fall into each other and there we go.

We have something like this now. We place our coil on this part and make it stay in place with a bit of hot glue. Now we make like 10 more of these here. I have my 10 fireflies and if I turn the fan on they don't have led you see they rise to some extent.
but if I raise the top a little bit see the rise much more which means the top vent is stricting the airflow. What do you know? I Had to redesign the top exhaust vents too to make sure the air flows better and lifts my fireflies. I Changed the design of the vent because I realized nope this new vent is pretty. It's printed in two parts and goes together like this and is held together by those long screws.

Nope. Here is the final update of the Nope. This is hopefully my final top Lantern design. see: I Put some vents in this top part because the electronics goes in here and I want some of the fan air to blow on my electronics and cool it down.

This is my original base design and this is the updated one. see I Had to raise it a little bit higher to provide a greater opening because I realized we need more air to get to the fan to blow the fireflies stronger and it looks prettier too. And I'm back after a month now. We build Electronics like so and they will go on the top and bottom of the glass.

Nope. First, we solder the current limit circuit. fine tuning a bit. Who could have guessed that what you designed on paper and simulate doesn't quite match reality? Wow.

Transistor is getting hot too close enough. Here's the circuit. Let's Power It Up Troubleshooting time. Here you go.

Finally functional. Let's bring close my Firefly and see if it turns on. Nope. I guess depending on the angle and how close it is to the winding, it could turn on.

What if I bring the coils closer to each other. Let's see. ooh, it's more uniformly on in the middle, not very uniformly on the edges. but I guess it's okay I like the green LED but I made one Firefly with wide LED Since it was brighter, let's see.

Oh there you go. Barely turns on I thought it was brighter. Yeah, see the yellow green LED is on more often because although the white LED was brighter at the same current, it requires 50 percent More Voltage to turn on. So because the voltage between the coils is often lower, the green LED turns on more often.

So what color LED should I pick for my fireflies? See, the white Led doesn't turn on very often, but when it turns on, it's a flash of white light. The green yellowish LED is more continuously on, but it's dimmer. Let's ask you. Okay, so around 30 like the warm white and around 70 percent like the original fireflies.

greenish yellow. So I'll make seven of them greenish yellow and three of them white. Also, I bring the coils closer in the middle so that there is more uniform magnetic field I think I should do that. Here is my beautiful coil holder that would go around the glass like so I Think we have everything we need.

Let's just put everything together. The plan is to send the positive and negative Powers through the brass rods to the circuit on top. Thank you Foreign thank you! Nice giveaway time. Well, I'm not giving away anything my sponsor Keysight does, but they'll throw in another extra scope per event for you my viewers.
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13 thoughts on “Making a lantern full of fireflies”
  1. Avataaar/Circle Created with python_avatars Agaldoo says:

    You can use 2 windings on a firefly

  2. Avataaar/Circle Created with python_avatars Missed Song Channel says:

    finally, a non dangerously product

  3. Avataaar/Circle Created with python_avatars Roy says:

    Holy crap, it worked!

  4. Avataaar/Circle Created with python_avatars Mark Eckelkamp says:

    This is awesome. Do you plan to release plans for this?

  5. Avataaar/Circle Created with python_avatars fullsend says:

    Can we pretty please have the files to make one too?

  6. Avataaar/Circle Created with python_avatars Xcoder112 says:

    That's how you do stuff for real!

    Contrary to just making lots of VFX animations of stuff, collecting tons of money on Kickstarter, then finding out that in reality nothing works as planned, and finally delivering nothing or something that looks totally different as in the animations and offers 1% of the promised features/performance for three times the promised price.

  7. Avataaar/Circle Created with python_avatars Serveck says:

    "Tapping these were not easy man. I feel hurt and bruised"

    The most based part of the whole video

  8. Avataaar/Circle Created with python_avatars James Paslawski says:

    Where can I get one?

  9. Avataaar/Circle Created with python_avatars ShioriWhitefeather says:

    every time he goes into the science of things, it's like he's speaking an alien language. I don't understand any of it.

  10. Avataaar/Circle Created with python_avatars Hunter Wall says:

    something to consider, if you make a V2 – instead of having a single axial fan matching the entire width of the glass, giving you a uniform-ish column of air, maybe try restricting the air to multiple "hotspots" of high air pressure by putting a restrictor plate on the bottom with a handful of holes in it that are near the same diameter as the fireflies? that way instead of a vortex, you get columns that bobble the fireflies around.
    Aside from that, this project is crazy awesome and I'd actually pay money for one of these to sit on my desk. They're like a lava lamp on crack.

  11. Avataaar/Circle Created with python_avatars It's Australia Day Every Day says:

    Bloody fantastic

  12. Avataaar/Circle Created with python_avatars Alexander Reddekopp says:

    So these will be sold as a hobby kit, when?

  13. Avataaar/Circle Created with python_avatars ElectroBOOM says:

    Thanks everyone for the kind words! It's good to see a hard project like this is well received. You make everything worthwhile!
    And if you are interested, I was using PETG material on my LULZBOT 3D printer. PETG material is stronger than PLA, and although PLA surface finish looks nicer, PETG is not too bad either. My initial prints were done with a setting with lower temperature, which made the layers not stick too well. So I raised the temperature for later prints.

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