You’ve probably heard something about wireless charging already. More and more devices have come out which support this technology and allow you to charge your phone without cables. You will probably also have heard terms such as Qi, induction and wireless coils. This article will explain what Wireless Charging exactly is.
Explaining often heard terms
Let’s start by shortly explaining some terms to take away the confusion about wireless charging, or induction charging.
Induction Charging – This is the physical principle upon which wireless charging is based. When someone speaks about wireless charging, they are automatically also speaking about induction charging.
Qi Charging – This is a standard for wireless (or induction) charging which has been developed by a consortium of large companies, universities and other parties, including almost all major phone companies such as Samsung, LG and many others (https://www.wirelesspowerconsortium.com/member-list/). It has become the dominant standard for wireless, or inductive, charging, which almost all devices these days use.
Wireless Coil or Patch – The working of inductive charging depends on two wired coils (how this works will be explained below) which transfer power to each other. Both the charging device (E.g. power bank) and the charged device (E.g. phone) must have such a coil to allow wireless charging.
How does wireless charging work
Without delving into the exact physical explanations: when electricity ‘travels’ through a copper wire, it provides an electromagnetic field. The inductive coil used for wireless charging has a special placement of copper wires to create a specific magnetic field. The magnetic field which is created by the sending coil (E.g. charging station) interacts with the receiving coil. In turn this magnetic field is turned into power by the receiving coil and then transferred to the device (E.g. mobile phone).
In other words: Electricity – sender coil – magnetic field – receiving coil – electricity.
Is wireless charging safe?
In short: Yes wireless charging is safe
The idea of wireless charging sounds rather dangerous, as you may think of electrical current running through one place to the other, or potential of harmful radiation. In truth it is however harmless. First of all, as you have read above, the power is transferred through the use of magnetic fields. There is in fact no electricity flying through the air, but magnetic fields, which exists around us everywhere already also.
Secondly, the objection of radiation is slightly more meaningful, but also does not apply. The technology of wireless charging has been used in electric toothbrushes for decades, without any indication that it could be harmful. The devices are also not omitting anything unless both coils reach each other and even then any radiation is insignificantly little due to the close proximity of the devices. In addition to this, the consortium behind Qi has further shielded both the sending and receiving coil, minimalizing any form of radiation.
Why the Qi standard?
The Qi standard for inductive charging seems to have become the worldwide standard for wireless charging. This brings with it the advantage that all devices which use wireless charging are compatible with each other. In other words, you can charge any Qi inductive charging device on any Qi charging station. All phones, which use wireless charging, currently operate on this standard, as do virtually all accessories. This takes away any potential confusion among users of wireless charging.
There are several nice aspects of the Qi standard, which are used in all devices:
- The devices will not create the charging magnetic fields, until both a sending and a receiving coil are in close enough proximity.
- Both sender and receiver move to standby mode once the receiver has been fully charged
- The sending coil checks for the energy requirements of the receiving device and adjusts the flows accordingly.
- Both coils are shielded to minimize electromagnetic rays