Wireless Electrical via Electromagnetic Induction

Abstract

Wireless Electricity transmission or wireless power transmission is a process that takes place in any system, where electrical energy is transmitted from a power source to an electrical load without interconnecting wires. The traditional ways using electric power cables and electric batteries are often not satisfactory for mobile devices as the use of plugs and wires will limit the mobility. Therefore, the objective of this project was to build and demonstrate the concept of wireless power transfer at relatively large distances based on magnetic induction coupling between electromagnetic resonant objects. It consists of a transmitter as an electromagnetic resonator and a receiver to which the device to be powered was attached. The transmitter emits a non-radioactive magnetic field resonating at MHz frequencies, and the receiving unit resonates in that field. The maximum voltage absorbed by the receiver load was 10V at 0 distances and decreased to 0.567V at 6 cm distance. From the experiment, the receiver had the voltage of 2.582V for input current 3A, 1.356V for input current 1A and 0.678V for input current 500mA at 0 distances. The basic principle adopted was using two coils having the same magnetic resonance, in which one was coupled to the source and the other one was coupled to a device. However, the short distance between the two coils and the large coil size that used more space created a problem. Thus, the number of turns of coil with better quality of copper wire and input current source can be increased to improve the strength of the magnetic field. This is because when the strength of the magnetic field increases, the distance between the two coils can be longer, while the smaller size of coil can be used to reduce space.