Simple Wireless Power

Overall, this experiment does not require too many materials, many of which can be easily acquired.

The materials are as follows:

1. 30 gauge magnetic wire
2. Alligator clips with leads
3. 2N2222 NPN-Type transistor
4. Electrical tape
5. Low-power LED
6. Measuring tape
7. Scissors
8. Pliers/wire cutters
9. Battery (9V)
10. Soldering gun
11. Solder

12. Cylinder with 2cm diameter

All of these materials can be found at local hardware stores and specialty stores such as RadioShack.

The first step in transferring wireless power it to make the coils. The two coils consist of one inducer and one receiver coil. They are made in the same manner, except the inducer coil will need a center tap.

To build the Inducer Coil, measure out 3 meters of 30 gauge magnetic wire. Then take the cut wire and begin wrapping it around your cylinder, leaving a sizable lead. After about half of the wire has been used (about 15 turns) create the center tap. This is done by pulling about 2 cm of wire away from the coil and twisting it. Do not cut the wire! Next, finish wrapping the wire around the cylinder, leaving another lead. To prevent unwinding, put 3 pieces of electrical tape on the coil. This will not effect the overall electrical output. You are now finished with the inducer coil.

The receiver coil is made like the Inducer coil, but without the center tap. To accomplish this, simply keep winding the coil without stopping.

***Helpful tip: Scrape off the enamel coating on the wire to ensure a good connection.

The transistor is the brain of this operation. Its purpose it to connect and disconnect the power at a rapid pace, thus creating a changing magnetic field in the inducer coil. This changing magnetic field is what induces an electric current in the receiver coil; which powers the LED.

To properly connect the transistor, you need to attach the correct coil leads to the correct transistor terminals (emitter, base, and receiver). The transistor will be soldered on.

Emitter will go to the negative of the 9V battery

Base will go to one inducer coil lead

Collector will go to the other inducer coil lead

Simply solder the terminals directly to the leads, and the connection will be secure.

The LED will be soldered to the two leads of the receiver coil. This allows the LED to be powered easily when the receiver coil is moved around the magnetic field. Each LED terminal will be connected to one lead of the receiver coil. The positive and negative of the led do not matter, as the current in the receiver is changing.

*** Helpful tip: trim the ends of the LED terminals so that it does not awkwardly stick out from the receiver coil

This experiment is powered by one 9V battery

Emitter will go to the negative of the 9V battery

Center Tap will go to the positive of the 9V battery

The full project can be represented in the schematic above

***Helpful tip: only connect the power to the coil when it is in use, as long periods of connection will deplete the battery and may fry the transistor. One way to solve this problem would be to connect a 100 ohm resistor to the base of the transistor (suggested by Majstor_nizasta), but since this project is supposed to be as simple as possible, I didn't include it.