Over the last decade, the advent of wireless telecommunications and wireless technology has allowed us to become more mobile. We now have mobile phones that allow us to make phones calls without a landline and technologies such as 3G and Wi-Fi that allow us to access the internet from anywhere we like. We also have technologies such as NFC for sharing information wirelessly and Bluetooth for connecting to other devices. Finally, we have cloud storage services and clever apps such as AirDroid for synchronising files and phone numbers without a USB cable. These technologies have allowed us to live more flexible and more mobile lives away from the constraints of our desk.
Many of today’s smartphones contain just two ports: a micro-USB port and a headphone jack. Although micro-USB ports can be used for a range of things including charging, data transfer and video over MHL, most of us use our micro-USB ports solely to charge our handsets. Could we envision a future without micro-USB connections on our phone and whereby our handset would be charged wirelessly?
Wireless Power Transmission: The Science
Faraday found that when electricity flows through a wire, magnetic fields are formed around that wire. He also found that when magnetic fields change in direction or size, electricity is “produced” in a wire inside that field. Combining these two laws of physics, we can see how wireless power transmission is possible. By starting with an alternating electrical current in one wire, we produce rapidly-changing magnetic field. This rapidly-changing magnetic field creates an electrical current in a second unconnected wire. Although we have two separate, unconnected wires, it is still possible to transmit power between them. This is the principle that lies behind wireless power transmission.
Wireless power transmission is already being used in commercial electronic devices. Electric toothbrushes are a great example: as your toothbrush regularly comes into contact with water, it would be unsuitable for it to have a charging port whereby water could enter the device. To avoid this happening, electrical toothbrushes make use of wireless power transmission. The base of your electric toothbrush contains receiving coils which can take power from the transmitting unit (charging station). As power is transmitted entirely wirelessly into the toothbrush, the toothbrush itself can be designed to be sealed and entirely watertight.
Wireless Charging On Mobile Phones
Until now, very few phones have supported wireless charging. The most widespread commercial adoption of wireless charging has so far been on the Pre and Pixi handsets from Palm (and later HP). HP’s TouchPad tablet also supported wireless charging before the product was discontinued. All of Palm’s mobile devices could be charged wirelessly by placing them onto a “Touchstone” charging accessory.
Finally, another commercially-available solution for wireless charging is Powermat. Powermat attempts to retrofit wireless charging onto older handsets which do not typically support it. It does this by providing a special receiver case. The case contains a series of coils that can receive wireless power and will charge up your battery using the phone’s standard charging port. Unfortunately, third party solutions such as these can sometimes be fairly cumbersome, expensive and difficult to use.
The Future of Wireless Charging
The Consortium has recently developed the Qi standard for wireless charging – a standard that can eventually be used by all kinds of devices including smartphones, tablets, laptops and more. In the future, we could see Qi-enabled tables in coffee shops, restaurants and other public places – a great alternative to fighting over scarce power sockets in the corner of the room and navigating a maze of tangled power cords.
According to the Wireless Power Consortium, there are no known adverse health effects of using a wireless charging solution. This means that the future of wireless charging now depends on whether manufacturers integrate it into their products.
Your thoughts…
In this article, we’ve discussed how wireless charging solutions work, the handsets that currently support it and looked at what the future might bring for wireless power. What do you think of wireless charging? Would you prefer to charge your smartphone with or without wires? Is wireless charging more hassle than it’s worth?
If you were designing your perfect giffgaff handset, would you implement wireless charging? We’d love to hear your thoughts… please drop us a comment below and let us know your thoughts!
Ken Lo writes about mobile technology and the mobile industry at Ken's Tech Tips.