Intro:

In this instructable I will show you how to achieve wireless energy transfer with extremely simple circuit.

Device is able to transmit energy wirelessly, to very limited range of about few centimeters.

This device is experiment, build for demonstration of principle, it lacks solid stand, switch, and/or more stuff... (it could be packed in some kind of box or something similar...)

It is to some extent, connected to my previous instructable (Joule thief wireless energy transfer - https://www.instructables.com/id/Joule-thief-wirele... ).

Disclaimer

You are responsible for yourself and your actions.

(and, you have to be very gifted to hurt yourself with this device :)

Materials and tools needed:

Enameled magnet wire

1x Piezo buzzer

1x led diode, for detector ( I used 3 mm blue...)

Super glue

A battery ( I used 9V)

*optional 1 old CD

*optional 2 alligator clips, or battery adapter

*optional piece of sponge

Pliers

Scalpel

Principle of operation

Buzzer is simple piezoelectric element driven by an integrated oscillating electronic circuit, which creates square wave, at few kilohertz, to produce sound.

If buzzer is connected to the air gap coil in series, it can be used to transmit some energy wirelessly to nearby coil.

My buzzer work on 5 - 6 volts, driving about 150 mA of current, so it can mainly be used as a demonstration of principle of em waves, wireless energy transfer, transformer, etc.

Device can be annoying.

Step 1: Building Device

Transmitter coil

Took enameled magnet wire, and wrap it around toilet paper roll, beer can, or something similar ( about 3 – 5 cm in diameter, don’t make it bigger, because buzzer use low current, so bigger coil will not work properly).

First let some 5 centimeters of wire free, for connection, and start to wind magnet wire on empty paper roll. Wrap wire of the coil in one, same direction. Wind about 30 - 40 turns of wire, then left some free wire on the end, and you finish your coil.

Careful remove your coil from paper roll, firmly holding coil, then wrap free coil ends perpendicular around coil, few turns is sufficient. Add a drop of super glue on coil.

Next, you have to clean ends of enameled wire, remove isolation using scalpel.

Connect buzzer to the coil

Connect wire from one side of the coil to one buzzer lead (longer lead is positive) simply wrap wire on it.

Cut another piece of wire, about 10 cm, and remove isolation from its ends. Wrap it around second free leg of buzzer (shorter one – negative).

Attach alligator clips, or battery adapter on the free ends of wire – one is coil end, and other is from the buzzer lead.

Receiver

Receiver is just simple coil of wire. I’m using one from my earlier project. It is attached on CD, to support it, just because I’m used very thin wire from old, salvaged transformer.

Took enameled magnet wire, wrap about 30 - 40 turns, it should be similar size with transmitter coil. You should also wrap your coil in same direction as transmitter coil. Strip insulation from both ends of coil and connect led diode to ends or receiving coil.

Glue everything.

Step 2: Add Power...

Connect to the battery

Now connect your battery to your device. The buzzer is making loud noise...

Took receiver coil, and get it near to transmitter coil, led should emit light, as you get closer to the coil.

If the sound is unbearable (after some time, it will be...), you could glue a piece of sponge to the top of buzzer, it will reduce torment...

So, what to do with it?

Except for of lighting up one led, or two, it can’t be used for some more powerful or practical applications. Mainly because power is limited by buzzer ( my is about 150 mA). As I say earlier, it can mainly be used as a demonstration of principle of em waves, wireless energy transfer, transformer, etc.

NOTES!

Buzzers come in great range of voltage, current, and sound (frequency ) ranging. Before start to build check that your battery is similar ratings with buzzer (some greater voltage won’t harm device, if you don’t use it for more than few minutes...).

And, again, this device can be annoying.