Did you know Nikola Tesla was the first person to achieve wireless charging? That's right: your brand new cellphone charging technology is actually over 100 years old. Or, at least, the principles that rest behind it.
Are you wondering how that's possible? And how wireless charging works? Well, you've come to the right place.
Here, we'll explain the basics of wireless charging. And we'll cover how it can be modified to charge larger objects. Maybe one day you can use wireless charging on your electric car.
How Wireless Charging Works
So, how did Nikola Tesla invent this? After all, the technology we use this for didn't even exist until long after he was alive.
Well, he demonstrated magnetic resonant coupling, which is how wireless chargers function. How wireless charging works is by using an electromagnetic field to transfer electricity between objects.
So, how does wireless charging work apply to your phone? Your wireless charging mat contains an inductor -- coiled wires surrounding a bar magnet.
When your charger is on, an electric current passes through it to create an electromagnetic field around the magnet. This then transfers charge to your nearby phone.
The charger pad converts the voltage into alternating current (AC). This goes to the transmitter coil to create the magnetic field. When your phone receives the charge, it converts it into direct current (DC) to charge your battery.
The strength of these fields decreases quickly with distance, which is why your phone has to rest on top of the mat. This also means that it's difficult to transfer large amounts of power this way. It's all dependent on how many coils can fit around that little bar magnet and the magnet's strength.
That's why we've had to wait so long. It's taken this long for making many loops of wire and a tiny, strong magnet cost-efficient. With larger coils, even more energy is transferable. That's why this patent for wireless car charging requires much bigger coils: up to 25 cm in diameter.
The problem is that wireless charging can't be performed through metal or thick cases. That means smartphones using this have to have either plastic or glass backs, and either must be removed from their cases or have thin plastic ones. And that leaves your phone much more susceptible to damage.
The Competing Wireless Charging Manufacturers
Just like Tesla's AC versus Edison's DC electricity argument, there are two competing types of wireless charging. Qi and AirFuel Alliance.
Qi Wireless Charging
Qi (which is pronounced "chee") was created by the Wireless Power Consortium (WPC). This is what your phone uses. Backed by Apple, Google, and Verizon, Qi appears to be becoming the wireless standard.
Qi focuses on pad-style charging and only travels a short distance (less than 1.5 cm). It requires tight coupling between charger and device.
The AirFuel Alliance
There actually used to be three players in wireless charging. But the Alliance for Wireless Power (A4WP) and the Power Matters Alliance (PMA) joined together to form the AirFuel Alliance. Supported by Dell, Samsung, and Duracell, this competitor isn't something to ignore.
AirFuel uses uncoupled radio frequency charging. This allows charging across a distance of several feet but sacrifices power. So you can walk around with your phone while it's charging, but it's going to take a much longer time to charge.
Many of their programs are still in testing. But AirFuel believes this is will lead to widespread public infrastructure charging for free. It's keeping Tesla's dream of free energy alive.
Now You Know Everything About Wireless Charging
Now you no longer have to wonder how wireless charging works. But what about those days where you're away from home and forget to bring a charger? Read on to find out tips to extend your phone's battery life.
Experience wireless charging for yourself!
P.S. If you're looking for a charging dock for iPhone or Apple Watch, check this out!