# Wireless transfer of energy

• redhot2k4
In summary, the conversation discusses a wireless system built by the speaker and their desire to apply theory to calculate the transfer efficiency over certain distances. They mention a paper by Andre Kurs which provides a formula for transfer efficiency, but it may not be directly applicable to the speaker's system due to the use of self-resonant coils. The speaker seeks advice on whether the same formula can be used for their system.

## Homework Statement

I have built a wireless system as described at the following site http://www.ar2r.50webs.com/wte/wte.html" [Broken]

I would like to be able to apply some theory to it and calculate a theoretical value for the transfer efficiency over certain distances

Does anybody have any idea of the theory I would need to use??

## The Attempt at a Solution

In a paper by Andre Kurs, "Power transfer through strongly coupled resonances" he derives a formula for transfer efficiency from coupled mode theory however it is complicated and the coils he uses are self resonant, where as mine have a raised capacitive plate making them an LC resonant circuit

Any help would be greatly appreciated

Cheers

Last edited by a moderator:
redhot2k4,

Would it matter whether the coil was self-resonant or not? The self-resonant inductors still use capacitance, but it's part of the coil... I would think you could use the same formula.

Michael
http://www.starmanelectric.com

## What is wireless transfer of energy?

Wireless transfer of energy, also known as wireless power transfer, is the transmission of electrical energy from one source to a receiving device without the use of physical conductors or wires. This technology uses electromagnetic fields to transfer energy wirelessly.

## How does wireless transfer of energy work?

Wireless transfer of energy works by using two coils, a transmitter coil and a receiver coil. When an alternating current flows through the transmitter coil, it creates an oscillating magnetic field. This magnetic field induces an electric current in the receiver coil, which can then be used to power a device.

## What are the benefits of wireless transfer of energy?

There are several benefits to wireless transfer of energy, including convenience, safety, and efficiency. With wireless charging, there is no need for cords or cables, making it more convenient and eliminating the risk of tripping over wires. It is also safer since there is no risk of electric shock. Additionally, wireless transfer of energy can be more efficient than traditional wired charging methods.

## What are the limitations of wireless transfer of energy?

One limitation of wireless transfer of energy is that the distance between the transmitter and receiver coils is typically limited to a few centimeters. This means that the device being charged must be placed close to the charging mat or pad. Additionally, the efficiency of wireless transfer of energy decreases with distance, so longer distances may result in slower charging times.

## Is wireless transfer of energy safe?

Yes, wireless transfer of energy is considered safe for everyday use. The magnetic fields used in wireless charging are non-ionizing, meaning they do not have enough energy to damage cells or cause harm to humans. However, it is important to follow manufacturer's instructions and avoid using incompatible devices with wireless charging technology.