You've surely seen some of those videos on youtube about levitating stuff.

In this Instructable, i will share with you the process of making a levitating key-holder shelf. It wasn't an easy build, since i am not good in electronics, but after some research it was done.

With the electromagnets in this settings you can levitate up to 34 Gr.

I hope every one will finde this useful.

( I will upload Pdf's, for the different cuts in this project, in a couple of days )

Step 1: What You Will Need :

For making the box :

- some wood, i used a thickness of 3 mm.

For the Electromagnets :

- 5Volt-Regulator 78L05 x 3 ( 0,2 USD x 3 )

- hall sensor SS495 x 3 ( 4 USD x 3 )

- op-amp UA741 or LM348 x 3 ( 5 USD x 3 )

- P-channel MOSFET IRF4905 x 3 ( 1,25 USD x 3 )

- capacitor 10 uf x 3 + 100 n x 6 ( 4 USD x 9 )

- resistor 10 k + 100 k x 3 ( 0,1 USD x 6 )

- an electromagnet 15 mH, 2.4 Ω1.5 A maximum1.5'' diameter x 1.0'' length x 3 ( 14 USD x 3 )

- N52 neodymium disc magnet1/2'' diameter x 1/4'' thickness, 6 gNi coated x 3 ( 4 USD x 3 )

- a board for soldering components

TOTAL PRICE : 108, 2 USD

Otherwise you can buy a kit, a good place is from http://zeltom.com/products

a price for : 48 USD for a kit

Step 2: Building the Box

I used a laser cutter from my friends school to cut the pieces, it is straightforward, i will attach the drawings here. otherwise just follow the steps.

The rings are made to hold the electromagnets in place.

Step 3: The Electromagnets - Some Theory

The electromagnetic levitation controls the magnetic field generated by an electromagnet to levitate a small magnet in midair. The small magnet levitates in the air indefinitely without any disturbance.

The physics behind it is to simply provide a magnetic force which equal and opposite to the gravitational force on the object. The two forces cancel and the object remains suspended. Practically this is done by a circuit which reduces electromagnet force when an object gets to close, and increases it when the object is out of range.The vertical position of the levitating magnet is measured using a linear Hall effect sensor and the current in the electromagnet is controlled using a digital signal controller.

Step 4: Building the Electromagnets

Since i am not good in electronics, I bought a kit from http://zeltom.com/products, . So i cannot share the schematics here. So i wont go in details here, since if you choose to buy the kit it is self explanatory.

But there is a lot of tutorials out there on how you can build your own levitation device, one of the best websites is this one : http://www.bis0uhr.de/projekte/schwebekugel/englis...

( the items of my component list are compatible with this schematics )

When the electromagnets are built, put them inside the box, inside the wooden rings, so they can be hold in place.