I might be dumb but I assumed plastic isn’t conductive. How do those wireless chargers work?
I’ve tried googling it but the answer is too complicated for me to understand lmao
In: Engineering
As a rule of thumb — things that are not conductive to electricity tend to be conductiver to magnetic field and vice versa.
The charger generates a changing magnetic field. This magnetic field permeates the plastic case and causes electric current in a coil that is inside the device that you charge.
You know those black boxes connected to your laptop charger chord? If you follow the wire from the socket plug end and the wire from the laptop plug end, you’ll be surprised to know they don’t actually ever touch. That’s right, your laptop charger isn’t one big wire, it’s two disconnected wires.
So how does all that power get to the other end if there’s a big gap in the way? Scientists found that if you wrap the wires up like coils, the moving electricity creates a special magnetic field around it (Like fridge magnets). Scientists also discovered that this works two ways – another coil in this special magnetic field will get electricity flowing through it.
And there you have it. Electromagnetic Induction. A way to get electric power across two wires with stuff in the way.
In fact, if you could get a strong enough magnet and consistently jiggle it quickly enough near your phone, it could start to charge it. It would be pretty exhausting though. (The power charging your phone is coming from your body!)
your right, plastic isn’t conductive, but the wireless chargers use something called induction to pass power.
basically, running AC (ie normal mains electric) power though a coil of wire creates a magnetic field. that process also works in reverse: a changing magnetic filed will create (induce) a current in a coil of wire. this is how electric motors work, and dynamos that convert turning power into electricity (like in power stations).
So, your phone has a coil of wire built into it, which picks up the magnetic field that the wireless charger is pushing out, and that changing magnetic field creates a current that is then fed into the battery as charge. it only works over a very short distance because the magnetic field drops off very fast.
does that make sense?
Close-ranged wireless chargers transmit power via magnetic induction. Most plastics don’t obstruct magnetic fields.
The same way a magnet will stick to a surface even if you put a thin sheet of plastic (or glass) in-between.
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