Cellphone wireless charging

[niranjan23]

Hello!! Experts
I am designing a wireless charging circuit for cellphones. I designed Transmitter circuit attached below using simple BC547 and IRF540 nMOSFET using Arduino to generate square wave of 32KHz for resonance of coil. And at receiver side I used simple 7805 regulator circuit for charging purpose. While experimenting I examine that charging is working but after monitoring battery percentage it seems like it is increasing by few percent and sometime it remains constant for long time. Also at first trial my battery percentage started decreasing after connecting to receiver. I dont understand that what could be the problem!! I giving my coil specification below.
coil turns ratio is 34:34
Primary coil - 34 turns 23 gauge (0.5mm)
secondery coil - 34 turns 23 gauge (0.5mm)
Since Im not good at analog circuit design.
Also the turns calculation I did it by referring transformer voltage and turns ratio! Tell me if Im wrong about it!!

In above circuit at the base BC547 I gave squarewave of 32khz(I dont knw why 32khz I read that somewhere on internet) and Supply is 12V and 2A Adapter. At receiver side I used simple 7805 circuit.

so please tell me what is happening wrong here?
How can I increase enough current to charge cellphone battery?
Is my turns of coil wrong?
If any Analog designer knew the solution on it please help me!
Thankyou!

 

[FvM]

And at receiver side I used simple 7805 regulator circuit for charging purpose.

What does that mean? We would at least expect rectifier and filter capacitor circuit.

You are talking about resonance, but there's no resonance capacitor at the transmitter side. And there should be a resonant receiver circuit as well.

Instead of guessing about charging effect, why not measure the DC output voltage and current?

 

[niranjan23]

@FvM Thankx for reply!!!

Ohk As I said Im not good in analog circuits.

I did measure DC voltage using DMM Im getting 30-39V at receiver side! And about current I didnt see!

So what should I do what are your suggestions on it ?? How can I increase current!!