As more gadgets become mobile and wireless, we’re breaking free of cords and wires
World over, smartphone manufacturers are working on newer technologies that can make their smartphones smarter than ever. One such technology is wireless charging. Means, you can charge your mobile phone without directly connecting the device to a power source using wire or cable. Rumors are that manufacturers like Samsung and HTC already have such devices. Samsung Galaxy S3 and HTC Rezound are believed to have this feature. The fact of the matter is that any gadget can have this feature provided there is a power transfer unit which must be connected to the power source and the power capture unit which will be embedded in the gadget to charge it.
However wireless charging is not a new concept, though it is being ratified in the recent times. Nicola Tesla, Austrian scientist, invented the wireless power transmission in the early 1900s during his famous Colorado Springs experiment. Unfortunately, his invention went into obscurity but now it is being accepted by major players in various industries.
How Does it Work?
Like the radio station transmits the songs in the form of radio waves and the receiver decodes it before we listen to the song, charging the cellphone or iPods or iPads wirelessly is possible using the same formula of physics. The wireless charging system includes 2 units—power transfer unit and power reception unit, both are made up of copper coils. The transfer unit is connected to the power source and it produces a non-radiative magnetic field around its space oscillating in MHz frequency. It means this field will not be widely spread across in space unlike the electromagnetic radiation. So, only the space around this transfer unit is filled with the resonant magnetic field.
When the receiving unit is brought nearby this non-radiative magnetic field then it starts resonating. This receiver is specifically designed to resonate in this magnetic field. The electric current running in the transfer unit coil induces another current in the receiving coil, hence transferring the power. This current generated in the receiving coil can be used to power the device. Using this method, over several kilowatts of power can be transferred safely and efficiently over significantly larger distances irrespective of the alignment.
Mevices kept from some centimeters to several meters far can couple together and transfer the power, but this also depends on some conditions like amount of power to be transferred, capturing device size, etc. So, the power transfer efficiency mainly depends on the distance between the transfer unit and the receiving unit.
Samsung and Qualcomm have recently joined forces and formed the Alliance for Wireless Power (A4WP) which aims to accelerate the development of wireless charging. Besides Samsung and Qualcomm, Nver Win Industries, Gill Industries, Peiker Acustic, Powermat Technologies, and SO Telecom are also members, and more are welcome to join, according to the 2 companies. Shipments of wireless power enabled devices are expected to surpass 100 mn by 2015, according to IMS Research, a market research company.