It is not a wonder but a real fact that, we can light a 3 V 1 Watt LED without any battery power. You can harvest that much “Free Energy” from a Computer cooling Fan that is resting in the Junk box. A Computer Fan generates around 1.5 Volts with a current of around 80 mA during its full speed rotation when coming close to a Table Fan. By adding a Joule Thief circuit, we can boost this 1.5V to around 4 volts. Well, that is a good idea. When the Computer Fan is close to a Table fan, the forcing wind from the Table Fan starts to rotate the Computer fan in its full speed. The 1.5V thus generating from the Computer fan appears in its connecting wires. Joule Thief takes this voltage and boosts it to 4V. It is sufficient to light a 3 V 1 Watt LED. The Computer Fan used in the project is an original one without any manipulation and not like the one found in some videos with a hidden battery. Let us see the “Free Energy Magic”. You can also name it as “Wind Power Project”.
The Fan used in the project is a 4 inch DC Fan. Its specification shows that it is rated 12 volts and requires 280 mA current for its operation. So when we connect the Fan to 12 V, it starts rotating. This is the normal working of the DC fan. Internally, the DC fan has four Electromagnets which become Magnets when we provide 12V (It works well between 6-12 volts). The opposing magnetic fields in the electromagnets cause repulsion and attraction. Due to this force, the fan starts to rotate. It is a Brush less DC motor.
Now what happens when we are not providing current and fan is rotating by “wind”. The reverse thing happens. The rotation of the fan generates a low voltage that varies from 1V to 1.5. We can tap this voltage for experimenting.
See the Multimeter reading.
Multimeter is connected to the + and – wires of the Computer Fan. The Computer Fan is rotating by the force of the wind from the Table fan. Multimeter reads 1.43 V. It is a good indication because the Free Energy is around 1.5V similar to that of a Pen cell. But this 1.5V is not sufficient for any experimentation even for lighting 1.8V typical LED. But we can Boost this voltage using a Joule Thief circuit to light any kind of LED including high power 1Watt LED. The Joule Thief circuit delivers around 80mA current, sufficient for getting good brightness from the LED.
So first make a high efficient Joule Thief circuit.
For details about the winding of coil and working of the Joule Thief circuit, see the following link. You can easily learn the Toroid winding and connections. It is not repeating here, so click the link.
This is the circuit of the high efficient Joule thief.
Now connect the wires of the Computer Fan to the input of the Joule thief just like we are connecting 1.5V cell. Now place the Fan with the Joule thief, very close to a Table Fan. See image.
The forceful wind from the Table Fan, will rotate the Computer Fan. The 1.5V thus produced by the Computer Fan will be the power source for the Joule Thief. It then boosts the 1.5V to around 4V that lights the 1Watt LED.
Note : Use a large 4 inch Cooling Fan to get good result. The 2.5 inch and 3 inch Computer Fans will also work but efficiency will be less to generate Free Energy.
More experimentation is possible. Since around 4V is available at the output of Joule Thief, we can make a Ni-Cd battery charger for charging two 1.2V Cells. We can also use a DC-DC booster module to boost the voltage further to make a Mobile charger. You can fix the Fan in your Bicycle handle so that during riding you can harvest the free energy. Remember, you can expect only low current around 50 mA for slow charging. No problem, we are using Free Energy.