• Question: thank you for you guys for replying to my 12 messages it means a lot and has inspired me to do some science myself. At home I have done the volcano experiment and planning to do the red cabbage experiment. Ok enough chat and now to the question. As technology has gone so far do you think you could bring the new technology to the world. Do YOU think you could make the USB wireless charger for a laptop or a monitor ?

    Asked by The Ge Ni U S to Andrew, Jade, Jessica, Kevin, Lynn on 16 Jun 2015.
    • Photo: Andrew Fensham-Smith

      Andrew Fensham-Smith answered on 16 Jun 2015:

      I’d like to think I could! USB wireless chargers work by using something called ‘inductance’. If you take a magnetic, and spin it around inside a coil of wire, you can ‘induce’ a current – that is to say that you can start making electricity by spinning the magnet. If instead you spin the magnet by putting electricity through the coil, you’ve made an electric motor.

      So you can use inductance to transfer electricity from one place to another without using any wires at all. If I had to make a wireless charger, I think that’s the way I would do it!

    • Photo: Jade Owen

      Jade Owen answered on 16 Jun 2015:

      12 years ago you’d be lucky to fit 8 songs onto a MP3 player! Today you can fit hundreds.
      Wireless charging has just started being used in some phones so with the ever developing pace of technology we’ll soon be able to wirelessly charge laptops and other gadgets.

      I wouldn’t be able to make one myself but would be amazing to see!

    • Photo: Jess Wade

      Jess Wade answered on 16 Jun 2015:

      For sure! Although I work mostly with chemistry now, I actually have a masters degree in physics. The physics behind wireless charging is brilliant ! It is all because of how closely linked electricity and magnetism are. When we have current moving through a wire, we make a few magnetic field lines. When we have a magnet moving through a wire, we make the charges move. We actually call light ‘electromagnetic radiation’, because it has both electrical and magnetic pieces of information in.

      We use magnets to make charges in a wire.

      If we have a coil of wire and just put a magnet inside, then not much happens- the little charges sitting in the wire just think ‘ugh! if they aren’t making any effort I won’t move’. If instead we move our magnet in and out of the wire, the electrons are all like ‘hey! what’s going on?’ and start to wriggle about and carry charge.

      What we’re doing is changing the strength of the magnet ‘flux’ in a wire. We can think of it like water from our shower falling on bathroom tiles. If the water is all falling on a bathroom tile, we can change the amount of rain hitting the tile by:

      1. turning up the shower
      2. changing the angle that the tile is tilted at
      3. making the tile larger

      with the magnetic flux, we can change the amount of magnetic lines by changing the strength of the magnet, or changing the angle or the area. But differently to the shower and the tile, when we change magnetic flux we can create an electric field. the magnetic field pulls all of the little electrons in the wire and pushes them around the circuit so we can charge our phone. we use this to make electricity or motors.

      But we don’t actually want to carry magnets around all the time, so we use wires with alternating currents. Alternating currents means that there are negative and positive charges flowing through them. The changing current then changes the magnetic field of the wire, and this causes little electrons to jump about in wires nearby. The more of these little loops we have, the more charge we can get.

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