Wireless charging explained.
Introduction:
This is the transmitting of electrical power or energy from a given source to any load without use of the inter-connecting conductors. That is to say without any wires just a transmitter and a receiver.
Ideal for the continuous, instantaneous supply of electricity.
Think of it like just as we send data packets through the air when we use a modem/router while using the internet, in a similar way, we can send power/electricity through the air using magnetic fields.
History of wireless power transfer:
Nikola Tesla, the infamous inventor and scientist, first conceptualized “Wireless Power” in the 19th century. He began experimenting with wireless power transfer in around 1891.
“Power can be, and at no distant date will be, transmitted without wires, for all commercial uses, such as the lighting of homes and the driving of aero planes. I have discovered the essential principles, and it only remains to develop them commercially. When this is done, you will be able to go anywhere in the world — to the mountain top overlooking your farm, to the arctic, or to the desert — and set up a little equipment that will give you heat to cook with, and light to read by.”
Tesla used conduction based systems, instead of resonating magnetic fields to transfer power wirelessly.
He wanted to create a “Worldwide Wireless System”, as he called it, and wanted to use the Earth’s magnetic field to transfer power wirelessly across the globe. So, he began constructing a tower called the “Tesla Tower” in Long Island Colorado, USA.
However, due to advancements in telegraphy, telephony and other forms of communication at the time, Tesla’s plan seemed too unrealistic during that period of history. The tower was then scrapped and funding was stopped.
However, many of Tesla’s concepts and ideas would be used for telecommunication & advancements in communication in the future.
How wireless charging works with circuits:
Now let’s get to the point of this post how the wireless power is transmitted and regulated to charge phones and all devices like the cars, but before get far deep in that we first have to know about;
· Capacitive coupling.
· Inductive coupling.
Because they play the vital rule in the transmitting and receiving of the power and more so generate the coupling frequency between the two coils.
Capacitive coupling:
This is the transfer of energy within an electrical network or between distant networks by means of displacement current between circuit(s) nodes, induced by the electric field.
Inductive coupling:
In electrical engineering, two conductors are said to be inductively coupled or magnetically coupled when they are configured in a way such that change in current through one wire induces a voltage across the ends of the other wire through electromagnetic induction.
Transmitter circuit:
Now here the most useful sector is the combination of the 10nF capacitor and the coils (start point, center point and the end point) this series connection of the coil and the capacitor for the Capacitor-Inductor Circuit which generates the frequency that is feed to the N-Types MOSFET to generate the pulse that is transmitted in the surrounding air.
Receiver circuit:
For the receiver coil (start point and end point) like we all know from Faradays law of electromagnetism when there is a changing flux (pulse in primary coil) this induces and emf (Electromotive Force) in a secondary coil (receiver coil) which is then rectified using the four power diodes and then filtered and feed to the L7805cv regulator to output the constant 5V DC for charging a phone.
Other applications of this technology includes, wireless car charging, telecommunication transmitting and electromagnetic waves.
Conclusion:
The possibilities “Wireless Power” unhinges are endless and it is set to revolutionize how we use power and electricity in the future, i.e. once the technology is perfected.
Wireless Power could eradicate our need of using expensive power stations, transmission towers and cables that transfer electricity.
It’s a century old dream first formulated by Nikola Tesla and it is yet to be perfected at the turn of this new decade. But it has the capability of changing the way we use power for good.
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