Monday, June 29, 2009

Wireless enery transfter

Is it necessary to complete wiring in your house for getting electricity connection? Is it necessary that you must have a cable to charge your mobile phones and laptops? Is it necessary to lay down the electric lines besides the roads? Normally our answer may be yes... But is it the future?

Once wire was required for telecommunication, cables are required for the transmission of power in and outside of the house, but what will be the future? Can we imagine a wireless world for everything, just like mobile phones; just go a step further... suppose the world may come to such a state where transmitting antennas are planted in the brain itself, what will be the advantage? Of course no more phone bills...

Wireless transmission for the purpose of communication is different from that of wireless energy transfer; power received is very important in communication only if the percentage of it is too low for the successful recovery of the signal on the other hand in this method the efficiency is the critical parameter. The word wireless power transmission is not a new idea to the scientific community.

In the 19th century Nicolas Tesla try to put forward the idea for long distance power transmissions. He even built a huge antenna for it, but he had to drop his project when he ran out of money.

One of his most spectacular displays involves the remotely powered lights in the Colorado Springs experiment station. In the infancy of transmission of electricity he may be thought that if we use wires for the transmission then the places should be crowded with wires and also about the huge investment in infrastructure to build the lines, but at that time world adopts wires and now we can see a number of lines are passing over our heads in the roads.

But how we can transfer power from the source to destination without wires? Is it possible? Inductive coupling is one of the answers on this way; it uses the theory of induction. When electricity is flowing through the lines, magnetic field lines are produced around the lines and if the other coil is places within range the electricity can be transmitted. Electric toothbrushes are recharged through this manner, there are various types of pads by different companies are available on the market; in which you have to place a mobile phone or mp3 player in that pad in order to recharge them.

There are other methods which are theoretically possible to transmit electricity, like through Laser beams, radio signals etc, but Laser beams need a direct path and this should create problems in long distance transmission, and we have to take care about our health and efficiency of transmission too. But as the proverb "Necessity is the mother of Invention", we have to invent method to transmit power to large distance to meet our needs- to transmit power to Antarctica, to overcome short circuits etc. But how? How we can transmit power with efficiency to these much large distances?

One of the new methods in this direction is resonant induction. Resonance is one of the beautiful phenomenons in Physics. Some months ago when I was watching a movie in 'Setmax'-I don’t remember which it was- but I still remember a beautiful line that displayed in the bottom of the screen. "Someone somewhere is waiting for you", I don't know whether it is real or not but one thing is sure; for success in a relation whatever be it is the understanding of feelings is necessary. This is the case with resonance. If frequency of one entity is matched with the natural frequency then there will be a resonance.

This method is suited for wireless power transmission too. In this method source's and receiver's frequency are made equal so that they form a resonant couple, and in resonant couples power can be transferred with very high efficiency. This method was discovered by a team lead by Marin Soljacic at MIT, they even powered a bulb in this method, in which electricity is transmitted to a coil and another coil which is hooked to a bulb and is tuned to the same frequency is placed some 2m away from it. And everything worked as theory suggested.

Thus In future, we can charge our mobile phone, laptop, PDA etc without using cables. The other advantage of this method is that as the frequency is critical for the high efficient transmission of electricity only the coils which are tuned for the same frequency will get the electricity with efficiency and the other is, magnetic fields are used for the transmission so there is not much health problems too. This may be prove and important step in our journey to a wireless world.

Let’s think about such a world where we can ride an electric car as long as we needed, whenever the charge in the battery ends it will be recharged automatically. May be in future there may be electric smart cards for the cars just like ATM cards, which can be used to recharge the battery. And just like mobile phone towers there may be electric towers everywhere not for holding the lines but for transmitting the power.

But is there any problem for health? Already we live in the sea of waves like; mobile signal, satellite signals, wireless hotspots, Wi-Fi, WiMax etc. I don’t know, but scientists say that in resonant coupling there shouldn’t be any health problems. In every front we are going from wired world to that of a wireless world. But let’s hope that the wire named friendship and relationships will be with the human beings. If that wire too become wireless then what will be the use of a mobile phone even if the battery is full?


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