The use of mobile devices is an increasingly important part of modern life and an extension of our brains which aid in our daily routine. Charging our mobile devices are one of modern lifes tasks which is constantly on our minds. We like to make sure that we have a charger handy to quickly recharge our constantly busy phones, and often find ourselves on the lookout for AC outlets in airports and bus terminals.

As technology advances, we find ourselves in less need for wires that twist and tangle, and chain us to an AC outlet, or an Ethernet port on the wall. We eliminated the wired internet connection (with Wi-Fi), the data transfer cables (with Bluetooth), and even landlines (with GSM/CDMA). Thanks to the many advances in the field of electricity and its applications, there is one area in which wireless technology promises less hassle when its time to charge our real life sidekicks, our phones.

The introduction of wireless charge not only makes easier, more convenient charging of our mobile devices, but, it also opens the door for many other applications.

How does it work?

Wireless charging works by transferring power between two coils through magnetic resonance, and inductive transfer. A wireless charger mainly consists on a transmitter coil, a receiver coil, and a control/circuit unit.

So here is how a wireless charger works: 1). - The transmitter unit is connected to a DC power supply, and stays in a standby status. 2). - When a mobile device with a receiver is placed on top of the transmitter unit, the transmitter measures the resistance from the receiver, and becomes activated. At this stage, the current is transformed to AC and travels through the coil, creating an alternating magnetic field that exerts its inductive power to the receiver.

3). - The receiver transfers the energy to the devices power control unit (which is why the charge status is shown), then to the battery.

Methods of Wireless Charging

There are several variants of wireless chargers out there. All of them use the same principle of electromagnetism. The two main methods, resonant and inductive, vary only on how power is transferred to the coils in relation to the distance between the transmitting and the receiving coils.

However, when it is time to switch to wireless charging, there are several factors to take under consideration.

1) Single coil: Single coil wireless transmitters, such as the one shown in Figure 1, are ideal when space is a factor. This method allows you to charge one phone at a time, but it is more efficient because of the decreased space between the mobile device and the transmitter whilst saving more energy.

2) Multi-Coil: Multiple coil transmitters are ideal for families because several phones can be charged at once. These transmitters may come in many different shapes, from mats, to circular, and can be placed in a central point of the house where all phones are charged without the tangling of cords, and the mess it creates.

The Bottom Line


The future of wireless charging lies in the magnetic resonance method, which significantly expands the distance between coils. This means that there is the potential for future applications ranging from charging all your mobile devices to powering your household electronics. Imagine not having to plug in anything ever. With electricity coming directly from coils on your wall, and all electronics and appliances wherever you want to put them, it is literally a brilliant future.