How Wireless Charging Works?
You must be seeing that many new mobile phones are now coming up with a wireless charging option. You don’t have to plug any wire to your phone for charging, just put it on a charging dock and it will automatically charge. Have you even wondered how wireless charging really work? Read below to know more.
In simple words – “wireless charging works by transferring energy from the charger to a receiver in the back of the phone via electromagnetic induction. The charger uses an induction coil to create an alternating electromagnetic field, which the receiver coil in the phone converts back into electricity to be fed into the battery.”
Wireless charging has been around since the late 19th century, when electricity pioneer Nikola Tesla demonstrated magnetic resonant coupling – the ability to transmit electricity through the air by creating a magnetic field between two circuits, a transmitter and a receiver.
But for about 100 years or so there were not much of a practical use of this technology. It started appearing first in electric toothbrushes. When Apple announced iPhone X with wireless charging the entire phone and gadget industry started taking wireless charging as a practical solution.
Today, there are nearly a half dozen wireless charging technologies in use, all aimed at cutting cables to everything from smartphones and laptops to kitchen appliances and cars.
How Wireless Charging Works
Let’s get into the physics of how wireless charging works and it implications. There are two different types of Wireless Charging. The most common type is Inductive Wireless Charging and later is Resonant Wireless Charging.
Inductive Wireless Charging
Requires direct physical contact between the phone and wireless charger. The charging coils inside the phone and the charger must be connected and aligned. The secret to how wireless charging works is electromagnetic induction:
- A transmitter coil in the charging base sends out a signal.
- The signal searches for a receiver coil, like the one in your compatible smartphone.
- When it senses one, electromagnetic induction begins.
- The electrons (electricity) inside the transmitter coil start to flow around in the coil.
- This generates a magnetic field, which is sensed by the electrons in the receiver coil.
- The electrons trapped inside the receiver coil start to flow around the coil due to the magnetic field.
- This flow of electrons inside the receiver coil is the electricity powering the battery in your smartphone.
Resonant Wireless Charging
Requires the phone, wireless charger and charging coils within each, to be within a specific proximity but do not need to be touching. Resonant charging works by creating a wireless transfer of electrical energy between two coils, tuned to resonate at the same frequency. Based on the principles of electromagnetic coupling, resonant-based chargers inject an oscillating current into a highly resonant coil to create an oscillating electromagnetic field. A second coil with the same resonant frequency receives power from the electromagnetic field and converts it back into an electrical current that can be used to power and charge devices.
Resonant technology let’s you power over a distance – from up to 50mm high and across a wide surface area. No need to match up the device and charging coil precisely (as with other technologies). Resonant gives users the freedom to continue working or playing while still charging.
With Resonant, you can charge multiple devices, with different power requirements, at the same time from one PTU power source. This gives consumers a common charging source for the multiple devices in their connected lives.
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