Wireless charging- How it works?

Wireless charging or Inductive charging is not a new concept it dates back to late 18th century and when rectifying property of crystals were discovered and in 1904 crystal detectors were developed and applied to radio receivers by our own Jagdish Chandra Bose and others. Crystal radios were popular as they used power of radio signals itself to power headphones.

Inductive charging or Wireless charging uses an electromagnetic field to transfer energy between two objects. To achieve this two devices are coupled such that one device sends energy through inductive coupling to an electrical device which in turn can charge battery or run the device.

Inductive charging became a buzz word in smart phones market when Nokia launched its Lumia phones with the wireless charging feature , however smart phones with wireless charging already existed in market.

Induction chargers are somewhat similar to transformer which uses an induction coil to create an alternate electromagnetic field from a charging base station and another induction coil in the device takes energy from this EM field and converts it back into electrical current to charge the battery.

Advantages

• Low risk of electric shock or shorting out.
• Protected connections- no corrosion as electronics are enclosed and safe from moisture and oxygen.
• More convenient - No need to connect thru a cable device can rest on stand or charging plate.

Disadvantage

• Lower efficiency, waste heat: Main disadvantage of this technology is less efficiency and loss of energy in environment.
• More costly than conventional charging system.

However newer approaches are being made to over come the challenges in wireless charging through the use of ultra thin coils, higher frequencies , and optimized drive electronics.  These technologies provide charging time comparable to conventional wired charging system.