# Wireless power transfer circuit design project on RC car. HELP

#### psoutzis

Joined Nov 15, 2018
8
Hi all,

Just joined the forum.
I am currently trying to design a simple circuit and demonstrate the wireless power transfer of electric vehicles on an RC car. I am a mechanical engineering student and my electrical knowledge is limited, so any tips will be appreciated.
So, the idea is to demonstrate the wireless charging technology using primary and secondary coils to charge the Li-ion battery which is connected to the RC car.

I draw a simple circuit (see picture attached) which has a: 240V AC power supply => Transformer(240V to 12V) => Oscillator (not sure what to include in here) => Primary Coil => Secondary Coil => Rectifier(AC to DC) => Battery.

So i thought of taking the RC car's Charger and open it and take the transformer out and use it. Moreover, i will go AC until the very end (battery) as there is no point in changing the current again and again.

Also, i know the specs of the Charger which is:
Input: AC 110-240V,
Output: DC 10V - 800mA
And also my battery is a 1500mAh 7.4V Lithium.

How i am going to figure out what to include in my circuit so i can get the right Voltage through the primary-secondary coils ?

What do you think of this project ?

Regards,

Panagiotis Soutzis

#### wayneh

Joined Sep 9, 2010
17,155
How i am going to figure out what to include in my circuit ...
Reverse engineering, or following a recipe. This is not a new technology and there's no reason to reinvent it. Following what others have learned and developed will get you much further.

I might start with the car-side inductive coil, since this might be the most constrained part of the whole thing. Maybe I'm wrong about that, but it seems like size and weight of the coil are issues on the car-side but of relatively little concern on the charger side.

You may need to reconsider the transformer choice. I think the inductive charger will run at a relatively high frequency and a "high" current. Once you know what that part of the circuit requires you can work on the power supply it needs. The transformer you have may or may not be a useful part of that.