Step 2: Creating the Primary Coil

The primary coil uses magnet wire, which is easy to get at RadioShack. http://www.radioshack.com/product/index.jsp?productId=2036277
We will use magnet wire as the material for our coils.

Next we need something to create the 147.7 square wave AC signal. I saw videos on youtube like this one. http://www.youtube.com/watch?v=SSgo_N-5JOg Which uses a function generator. Sadly, these cost a lot of money, so i wanted to get a low cost one, that still did the same thing, just not as high of a frequency. This http://www.sparkfun.com/commerce/product_info.php?products_id=9002 is great for what i needed. Cheap and simple.
This will be the main board to create the signal.

By using a pencil or nails on a 2 x4 and your magnet wire, you can make a pretty good coil. I did about 30-40 turns, depending on the thickness of your magnet wire. Magnet wire has a very thin coating on the top of it. To get this off you can light a match and put the magnet wire in the flame for a few seconds. Take the two ends of you coil and put it into the function generator on the top two screw terminals, one in each terminal. Polarity is not a problem right now because the signal will be AC. Now place your 0.02 uF film capacitor in parallel with the terminals you put the wire magnet ends into. Turn the function generator on and use your multimetter to get it to somewhere near 147-149 kHz by turning the potentiometers. Make sure the switch on the left of the board is set to square, and your good to go. The top to terminals will allow for an AC signal.

<p>None of your links from step 9 work</p>
<p>That's true :V</p>
<p>You fuckboi</p>
<p>Does it really work?</p>
<p>Can we use this for charging a mobile??</p>
<p>no...... it doesn't have that much current output......... </p>
So can't we increase the input current and use higher current components.... I'm new to electronics
<p>it's not my design brother.............. you need to ask the author ...... but what i think is....... that......yes..... you might need to upgrade the components ....</p>
<p>What grade of copper was used, like width/size of the copper coil used?</p>
<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...

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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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