How do wireless chargers work?

When we think about electricity, many of us automatically envisage wires, whether it’s fumbling around behind the television to connect the correct cables, seeing electricians work a colourful wire maze in an electric box – or simply taking out your phone charger when your battery level becomes critical.

These days the number of wires we need for our electrical devices is reducing all the time, and wireless power can now bring life back to electronic devices without the need for a physical connection. Wireless power technology uses charged particles to pass energy between devices before it’s converted back to electrical energy.

It was Nikola Tesla who showed the world that wires weren’t essential in power transmission in 1890. Using two copper wires, a primary coil could withstand massive amounts of charge. Once at maximum charge, the voltage was sent into the gap between coils, reaching the secondary coil, which was then able to produce lightning bolts. His ‘Tesla coil’ was first to demonstrate this concept, and while the breakthrough stood alone as an amazing invention, it would be over a century before the technology was used commercially.

Now wireless charging demonstrates a range of purposes and possibilities, that varies depending on how far the energy needs to be transported. Near-field applications use magnetic fields, while further distances, such as for in-space applications, require more complex techniques involving microwaves. This is often referred to as power beaming.