Wireless Power

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.

Comments

[nzemke]

Ok so I get everything your trying to do but I'm confused as to what model of rectifier to use? Or if that is even what your using? I picked up a full wave brdge rectifier (GBL005) from Radioshack...is that the correct thing to be using? Thanks ahead of time for taking the time to answer.

[NeMewSys]

Hi, great article!!
Your 147.7 square wave AC signal generator just retired from the market, are there any alternatives?

How do you know wich capacitor to use to get that frequency? Could you show us the math?

Thanks ;)

[danielkim802]

there's a newer version of the kit that can still produce the same output: http://www.sparkfun.com/products/10015

[bvd]

I am also very interested in this.

Can someone point me in the direction of a kit I could use to generate the 149KHz signal?

[hrishikeshp]

hey i checked that link and that one was retired too anybody have suggestions?

[ShogunD]

http://electronics-diy.com/store.php?sel=kits&sub=function_generator
Theres a possibility.
I haven't tried it yet but I plan on it.

[rohitforothers]

heh can any1 send me the a perfect list of components required for it
on [e-mail]
The faster the list gets to me the better...
plz help on...

[MadScientist101]

could you use a 555ic to replace the function genorater?

[robotkid249]

Yes, but it wouldn't be efficient...

[MadScientist101]

why, surely it would do the same job but less options

[Goodhart]

LM555's are power hogs...really !

[The nerdling]

dang i have heaps

[Goodhart]

Well, compared to their low powered cousins they are....still they are quite useful.....just not if you need to keep a battery fresh without recharge for awhile. I have a bunch of them too, as I use then for simple timing projects....

[The nerdling]

ok

[Goodhart]

Sorry, I just didn't want to discourage your using them...., they can be very useful for the right projects.

[The nerdling]

you didn't disgourage me for using them

[Goodhart]

Ok, just making sure :-)

[The nerdling]

ok

[n_cleaner]

Can you tell me the company of MULTIMETER?

[mgercak]

Can I have like just a list of materials I need to buy in order to make one that can charge an Ipod or something? thanks, my email is [e-mail]. The faster the list gets to me the better.

[coilsinamotor]

when u mean ac signal do u mean a 555 push pull circut cuz i what to build me own gnerator so i can put it in a nice box thankx :)

[Spaceinvader]

The Function Generator is out of stock :( so I look for another and I found this one, Can I use it too? http://www.allspectrum.com/store/product_info.php?products_id=569

[uberdum05]

Would some pre-wound RFID coils suffice for the job??? :)

[memo2634]

How do you go about choosing the frequency for the primary coil in the project? I'm assuming if the capacitor value is different, the frequency will be different as well.

Also you mention using nails on a 2x4 to wrap the wire into a coil. Is that done to keep the wire bunched in a tight group?

Based on the size of the coils, what kind of distance were you able reach? Lastly how many feet of wire did you end up using?

I'm working on a project for school that will implement this and it would help if I could get some quick help. Thanks

[calidude89]

Im very confused. Is the capacitance of the primpary supposed to be the same as the secondary coil? I only see one capacitor on the primpary. but you said you used 2 capacitors to make .02uf. Also the instructions differ from the pictures in value of capacitance. I purchased a function generator just for this project. I have 2 .01uf caps in series on my secondary coiil and 1 .01uf cap on my primary as shown in ur pictures, but it doesn't work.

[redbloomer]

dude i've been inspired by your so i decided to do something like that. and i successfully made it.. thanks for your ideas..

[TS1990]

this instructable interesting and I am trying to build one one my own. I am just a beginner and I have some questions, would you please help me out?
Q1. why did you choose 147.7 kHz for the frequency?
Q2. you said the two coils should be in tune, what is it that affects the frequency of the secondary coil?
Q3. what waveform comes out from the other end, is it sawtooth or something else?
Q4. how efficient it is?

thanks :)

[happybuilder]

 can you give me instructions on the plug from the generator?
can you conect the generator to a usb plug?

please answer me soon

[happybuilder]

 I'm building a wireless mouse with a pad that will have the generator and coil.

[robotkid249]

 It is a wall wart that plugs into AC wall power and rectifies it into 12V DC. I am not sure if 5 volts will be sufficient.

[happybuilder]

 so did you need it to just light the LED?

[happybuilder]

 (I'm a beginner at this)

[evangeline24]

in the circuit used in primary coil, what are the 5 ICs used? pls answer asap...
we'll gonna do this as investigatory project...

[Algag]

 anyone thats metric (even though I'm not) the measurements of the 2 by 4 he is talking about is 38*89 (millimeters) 

[gxb5443]

how big did u make the coil?

[Algag]

 as big as you want, i would say about 6 by 12 (inches) but you cant do that on a 2by4....well obviously

[koopatroopa]

is there anything inside the coild? is it and electro magnet?

[Algag]

 a coil of wire with energy running through it creates an electromagnetic field

[sk.mobeen]

what do you mean by 2x4....can u specify sizes in centi-metres or inches for both primary and secondary coils. for ex....primary(10cms x 5cms). please HELP.

[Algag]

 look at my above message