4 Comments

1. 

   Well, there is nothing so impossible under the sun.
   I believe that, its possible but the challenge is efficiency.
   How much power are going to generate and the capacity of the load (motor)?
   References :

   Comment by K.E.S. — @

2. 

   Yes, absolutely. What’s more, it’s actually quite easy. You won’t get significant amounts of power out of it but it will run a very small electric motor so long as you use a generator that is significantly larger than the motor you are driving.

   You’ll need something that you can use for windmill blades and a motor that you can drive as a generator.

   The best and easiest solution is to use a radiator fan from a modern car. Most modern cars use electrically powered fans and this is perfect for you because it takes care of the fan assembly and the generator in one go without the need for a complex assembly procedure. They are cheap and easy to get hold of too. Any car wreckers should be able to sell you one for under $20.

   This type of fan is not the ideal configuration for capturing wind (they are designed to generate airflow from electricity, not electricity from airflow) but the advantages you get from simplifying the construction process more than makes up for this. Also, as far as I am aware, they are all DC motors which is exactly what you need.

   Because a generator is identical in construction to a motor, this fan will generate electricity for you without any need for modification. All you have to do us hook up your small hobby motor to the terminals of the fan motor and put it somewhere where there is enough wind to get the fan spinning. You should be able to generate up to 12v depending on how fast you can get it spinning. If you find that it takes more airflow than you can manage to get it spinning fast enough, you can always construct a ram scoop (like a big funnel with the wide end open and facing the incoming wind and the fan across the narrow end) so that the wind is scooped in from a wider area and forced through the fan at higher speed. This doesn’t need to be that strong, corrugated cardboard (like you get from cardboard boxes) would probably do the trick.

   So long as you get the fan spinning at a reasonable rate, you should be able to easily power a small motor. Of course, as soon as the fan slows or stops, so does the motor so it’s not really a viable solution for real world applications. It should be fine as a simple experiment to demonstrate wind power though.

   If you want it to be a bit more practical (i.e. actually work in the real world rather than it just be for demonstration purposes), it would probably be better to run the motor from a battery and use the generator to recharge the battery. This is how proper wind powered systems work. However, the setup becomes more complex when you do this and some circuitry is required to manage the recharging of the battery, among other things, so unless you have some experience with electronics, I wouldn’t advise it.

   It sounds like this is outside of the parameters of your experiment anyway.

   The motor you are going to drive should, ideally, be able to run on voltages between about 3VDC and 12VDC but cheap and easy to find motors like this one (http://www.jaycar.com.au/ShowLargephoto.asp?id=3255&IMAGE=) that is designed to run on voltages from 3V to 4.5VDC will still probably work OK for your purposes. If it is fed 12V continuously for long periods of time, it may overheat and burn out but, considering your setup, it will probably last at least long enough to meet your needs. If you do go for a low voltage motor like this and you want to make sure you don’t damage it, just make sure that you don’t spin the fan too fast and monitor the temperature of the motor. If it starts getting hot (i.e. too hot to touch), stop it and let it cool down for a while before you start it again. It’s not too big a deal if you do burn it out though, these motors retail for about $2 so you won’t exactly go broke if you kill it.

   Good luck with it.

   Hope this helps.

   TV
   References :
   I’m an electrical/electronic engineer and have often dabbled in wind and solar powered devices

   Comment by tvsinesperanto — @

3. 

   I actually built a small windmill to try and power things at home and save money on electricity.

   It was pretty easy, I did it all on one Saturday afternoon, and I got everything I needed from the hardware store.

   Now i am using it power a couple of lamps and a small tv, so I am sure it would power your electric motor.

   Here are the plans that I used:

   Comment by Rebtl — @

4. 

   Yes.

   Hopefully, though, your science lab is too sophisticated to have a simple bar magnet, some wire, and a fan blade.

   Mount the fan blade on an axle of some sort: pencil, broom handle, etc.

   Mount the axle on some sort of support so it can turn freely.

   Mount the magnet on the axle at a right angle.

   Place a coil of wire a millimeter or so away from the path of the magnet’s poles.

   As the wind turns the fan, it’ll turn the the north and south poles of the magnet past the coil, creating a voltage.

   Use this voltage to turn a small motor.

   You might need a diode or bridge rectifier (found in the electronics lab, not the science lab) to convert AC to DC for a small DC motor such as is found in many toys.
   References :

   Comment by David F — @

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