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The power cord, I know you hate it. Sometimes, you just want to cut it apart! Well say goodbye to your power cords, because with the power of inductive coupling your device will not need to be connected metal to metal. Seemlessly your device can be charged!

This instructable will show you the basics of creating your own cheap and easy wireless power mat, which you can use to power your device through the air!

New Update: complete list of components.

Check out my new project on sending a balloon into space!! 

Step 1: What is it? How does it work?

A few years ago MIT created a system for transferring power wirelessly. They transmitted power over a two-meter distance, from the coil on the left to the coil on the right, where it powers a 60W light bulb. Back in 2006, this was a pretty cool thing. You can only imagine what the implications of something like this would be. Well, unlike most of us, we do not have the time or material goods like MIT has. So i have made this simple and easy to follow Instructable, so all of you good people can experience the joy of wireless power.

Inductive Coupling uses magnetic fields to transfer power. There is a primary coil, which generates a magnetic field. Then there is another secondary coil which is composed of a capacitor and a coil, the capacitor creates a resonant circuit with the primary and secondary coils. Seem easy? Well, before publishing this instructable I found many useful and a lot of non-useful info on the subject.

In my research I found, that to transfer power in very complicated. Once i did it I found that you do not need to go to MIT do do this sort of stuff. With a little electrical know how, this is easy.

It all starts with the transmitter. This transmitter needs to create 147.7 kHz square wave AC signal. Let me take a minute to explain this all. Level one on the frequency scale is Hertzs, then there is kHz, then MHz. MIT used a 10 mHz wave to drive there coils, but for this we will be using a 147.7 kHz signal so it does not get too complicated.

The secondary coil has a 0.02 uF capacitor. This will allow the two circuits to be coupled therefore, transferring power efficiently. The 0.02 uF capacitor is used only for this frequency, and the value of this capcitor will change depending on the frequency.

The primary coil creates a magnetic field, when another coil is placed near it, energy will be induced into it.

Be in mind that i could not get a hold of a 0.02uF capacitor so i used two 0.01uF capacitors connected together.

<p>A remix 2.0 ........ i've taken part in the contest with reference to this instructable ...... please support me friends..... thanks robotkid249 for the inspiration......</p><p>everyone please have a look to my instructable http://www.instructables.com/id/Wireless-Power-Transmission-Using-AVRs/</p>
So I made it..... I needed a function generator..... But it costs too much..... So I made it of my own..... And friends if you too need to make one of your own..... Check my instructable for &quot;DIY Function Generator&quot; Ain't advertising..... But just want to help all people out there........
<p>It was 1970 when we had a science fair in Olongapo city (philippines).i was in 1st yr.</p><p>Jackson high school when i saw this 120 volts AC 50-watt incandescent lamp hanging by a cotton string lit up about 6 inches away from a ferrite rod coil and circuit board.That got me hooked up in electronics.</p>
<p>What do you think of this circuit - https://www.youtube.com/watch?v=4UmVLfFNx7U . I think this is the simplest and cheapest system I have seen. Can this work with your primary coil?</p>
<p>visit.....http://powerbyproxi.com/ </p>
can you get ahold of a hertz-uF ratio for me. I would like to tamper with this concept if you don't mind.<br>
Would someone please provide a better schematic? I'm not sure if I'm building this wrong, but mine is not working, I did a lot of troubleshooting and etc but unsuccessful.. Any help would be appreciated..
i love this
<p>Has anyone built a WIFI Power Harvesting circuit that will power an LED as yet? If So please let me know the scematic, thanks. </p>
<p>MIT did't invent this its like 100 years old</p>
<p>damn right they dint invent this, it was Nikola Tesla, how can MIT claim to invent a device that was created 100 or so years earlier, Teslas main coil that would of supplied the world with free wireless energy was dismantled and sent to a dark room in A51, MIT are wrong to claim they invented this when they obviously didnt.....poor tesla ripped off by everyone he worked with including Thomas Edison, and Einstein, and now he's been ripped off again by a school</p>
Nicola tesla
Can i use wifi or bluetooth emission to power a led, if so could you explain...
Do the inductances have to match between the two coils have to be the same?
no, however the number of coils on both sides along with the distance between them (called the mutually inducive element) and the load you use will affect the applied emf to the secondary circuit.
oh so this will transfer power no matter what. If the the base and reciever were tuned to one another though there would be way greater efficiency, right?
If the Circuit reached resonance, there would be voltage/current magnification, which you may have to consider when choosing your components. the advantage would be that energy would only be dispersed A, in the resistive element, and in the space between the coils. i looked it up, and every time the distance doubles, you lose magnetic power by a factor of 4.
the load will have effect? How do you take that into account? So this way is just two arbitrary coils that will couple together. If you tuned the base and receiver to be in resonance, wouldn't that transfer as close to 100% power transfer as you can get?
here two capacitor of value .01 uf are connected in parallel or series???????
This is an amazing guide! Very informative. Thank you
<p>Aren't the exposed wires dangerous because AC is passing through them? How can this be insulated safely without affecting the resonant properties of transmitting and receiving coils?</p>
Looks like low voltage to me
<p>The power is so low that it won't hurt you. </p>
Thanks for the reply. Would that still be the case if I were to build a unit capable of powering a 40W 120V light bulb wirelessly? Would the conductive socket of the bulb and other exposed wires need to be insulated then?
<p>Well done but my main target is &quot; Transfer of electricity &quot; completely without any single wire. As we join hands in that research, we should also focus our aims at long distance applications. Let's connect at, aliganyirataddeo2014@gmail.com. </p>
<p>I see a heck of a lot of wire for something supposedly 'wireless' .</p>
wireless as in you are not physically hooking your device to a power source other than putting the receiver on it. make the receiver penang and you have wireless power.
<p>could you tell us the formulas required to calculate the values to prepare the primary and secondary coils and also the ratings of the components used to construct the required circuit to achieve the specific output(i.e voltage and amperes). </p>
Couldnt you use a crystal resonator on the secondary coil?
<p>Over doing it! Quartz resonators are in the kilohertz range.</p>
can the range be increased?....how?...is it posible to increase it to about 1meter or longer?.
yes the higher the frequency the longer the range
<p>Also, the thinner the effective cross section of the wire, do not go overboard or your skin effect will fry your wire.</p>
Is there a way to do this with a smaller amount of coil?
<p>Yes, it can be accomplished in the same manner by using the same ratio of wraps of wire (internal coil/external coil) (make sure it is insulated wire and away from anything flammable as sparks may still ensue (and DO NOT plug a circuit like this into a wall or anything above a 1.5v battery))</p>
hi, i'm liking this small DIY project :)<br>umm, what do i need to put in my mobile phone, mp3 etc. to charge it from the coils?
<p>You should be able to find the information by removing the back panel of your cell phone and observing the sticker on the battery, it should say something like &quot;6.5v 600mWh&quot; the second number is how much your battery stores, the first is the voltage it stores at. Though, you shouldn't really try to charge your phone in that manner, you will end up frying your circuit board and possibly over charging your battery (not fun, lithium burns require hospital treatment.)</p>
hello wmiddleton!!!<br>are you found the solution in your case???<br>my case like your case...<br>i hope u can share u solution to me...<br>thank you...
<p>Great,</p><p>wonder if I could make one too</p>
<p>Hello admin,</p><p> Your blog about this wireless power transfer is quite good for basic model but it has limitations of 3cm of induction area.</p><p>Research of Mit that you told is not complete ,Mit used a resonating coil prepared of large capacitors at both ends of inductive coil that produced a resonating frequency for large inductive coupling.</p><p>So,if you know further about it let me know .</p>
<p>hey admin can you contact to me in gmail, i wanna know something..my gmail is - vickybisht1995@gmail.com</p>
<p>Hello there. Awesome project.</p><p>It would be really helpful if you post the circuit schematic. </p><p>Thank you. </p>
<p>Well you can use OP-Amp to create a square wave of desired frequency, just google it, its very easy to make as it looks from the diagram cz I have never made it myself just studied it as a part of my electronics course.</p><p>You can do the same using 555 timer though its a bit less easy as compared to opamp one.</p>
<p>Hi! It's possible to make a transmitter in AC signal? not continue. I'm so interesting in this. </p><p>Thanks a lot.</p>
<p>That is awesome good idea only need loop of coil divert into electrical energy. Thanks for the share.</p>
where i get the circuit? <br>help me
where i get the circuit? <br>help me

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Bio: I'm 17. I enjoy making cool stuff, and promoting the "maker" community. Vote for my space balloon in the hurricane laser contest and hands ... More »
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