How Galaxy S6 Wireless Charging Works?

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It would be a stretch to say that a physicist, Nicola Tesla, invented wireless charging for Samsung Galaxy S6 some hundred years ago and then waited around for the world to catch up, but it wouldn’t be very far from the truth, either.

The core technology which powers wireless charging—no pun intended—has been around for nearly a century. Ever since Tesla demonstrated this, physicists have known that power could be transferred wirelessly via an electromagnetic field. The thing holding everyone back was how to make this work without the bulk and the cost.

Let us take it from the beginning. With the launch of the latest line of the Galaxy phones, introducing wireless charging created quite a stir. There is a small plastic-like disk on which you place your phone, and voilà! It starts gathering juice! There are no wires involved, no Persian knots in your pockets, and no bulky adapters.

It works on the principle of induction current. If you have ever used an induction cooktop, you have already used induction current. While the cooktop is used to generate heat, a wireless charger charges a battery. And next is an explanation about how it does that.

An alternating current flowing in a loop of wire coiled around a magnet would generate an electromagnetic field. This field can, in turn, be used to generate a current in a conductor coil placed nearby. This current can then be channelized into generating heat or charging a battery. This much has been known for a long time. The challenge was the bulk of the magnet and size of the coils required to make this work.

The challenge of creating sufficient power is compounded by the fact that the strength of the current generated depends on the size of the coil and the strength of the magnet. Also, the strength of the current generated reduces as the square of the distance between two coils, so this only works at very close distances. These were significant challenges. For the longest time, the technology to make very small magnets of sufficient strength or very flat coils made out of thin wires was not available. Not so anymore.

In recent times, the sizes have been reduced significantly; and like anything that is mass produced, costs have come down. Like any emerging technology, there are two competing standards that use two slightly different technologies to achieve this. There is the Wireless Power Consortium (WPC) that uses the “Qi” (pronounced “Chi”) technology, and there is the Power Matters Alliance (PMA).

The unique thing about the Galaxy S6 is that it is compatible to both the standards. This means you can use any of the chargers increasingly available in airports, hotel lobbies, and other public places to charge your phone.

The charging station, the flat plastic-like disk that we talked about earlier, has what is known as an “inductor,” which is nothing but a loop of wire coiled around a magnet. Its brother coil is hidden inside the body of the smartphone. When you place the phone on the disk, a tiny transmitter on either device talks to the other, establishing that this is a phone that is meant to be charged. And then the cosmic dance of electromagnetic fields begins charging your phone wirelessly. The transmitters ensure that voltage isn’t generated in something that isn’t meant to be charged, like a penny placed nearby for instance.

Samsung’s website reports that all this added paraphernalia adds less than 0.3 mm to the thickness of the phones, making them some of the slimmest in the market! So not just untethered, but also in shape!


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