It seems like wireless power transfer is all the rage these days. There’s wireless charging mats, special battery packs, heck, even some phones have it built in! And they all use inductive coils to transfer the power — but what if there was another way? Coils of copper wire aren’t always that easy to fit inside of a product…
As an experiment, [Josh Levine] decided to try making a proof of concept for capacitive power transfer.
He first demonstrates inductive power transfer using two coils of copper wire to power up an LED. The charging coil is supplied with 15V peak-to-peak at 1MHz which is a fairly typical value for inductive charging. He then shows us two glass plates with some tinfoil taped to it. Two LEDs bridge the gap alternating polarity — since the power is oscillating, so we need a path for electrons to flow in both directions. There is no connection through the glass, but when it is set on the charging plate, the LEDs light up. The charging plate is supplied with 30V peak-to-peak at 5MHz.
It works using the concept of capacitive coupling, or electrostatic induction. The main reason it isn’t used as widely as inductive power transfer is because it requires higher voltages to transmit significant power — which can be dangerous! But one good thing is it doesn’t cause as much interference because the magnetic field is largely confined between the two plates.
Now this is only just part 1, [Josh] is planning on continuing to research this and see if he can create a practical system for use — we’ll keep you posted!
We wonder what the next big thing in wireless power transfer will be? Will the next Tesla vehicle charge wirelessly in your driveway? Or maybe charging pads for quadcopters?