Looking for advice on motors for a small windmill (for kids)

[hugo_faurand]

Hello everyone !

I speak about energy to a fifth grade class. I want to build small windmills made of paper cup for the blades.
The goal is to light a LED when the windmill is running. I was looking for a small motor to do the alternator. I found this one and I wanted to know
if it could fit for what I want (or if you have any other suggestion).

I am not looking for a high efficiency device. They are kids, just seeing the LED lighting up while the blades are spinning is incredible.

Thanks in advance :)

 

[kuruman]

Have you considered a wind turbine kit? Here is one for the price of a hamburger which the kids can probably assemble under your guidance. Other options are available, of course.

 

[hutchphd]

I am not looking for a high efficiency device. They are kids, just seeing the LED lighting up while the blades are spinning is incredible.

Easy seeing of lighting depends on the color (threshold voltage) of the LED and whether the windmill will be "geared up" to increase speed on generator. Maybe a higher voltage motor would be easier. Probably need to experiment a bit.
These would probably do well. Worth a shot and cheap!! I would try both the 12V and 24V motor. I don't know this supplier.

 

[jack action]

This is a kit with a dynamo whose only purpose is to light a LED.

 

[Borek]

I wonder what is better: LED or a normal, old school incandescent bulb. LEDs are rather fragile and easy to burn if you don't control the voltage/current (not a problem to add a driver, but it breaks the simplicity of the design), bulbs are much more robust and there will be much more visible difference in their brightness depending on the rotation speed, which is another great teaching moment.

 

[berkeman]

Have you considered a wind turbine kit? Here is one

Is that one of those new-fangled ones that run forever on one set of start-up batteries?

 

[kuruman]

Is that one of those new-fangled ones that run forever on one set of start-up batteries?

View attachment 322596

I don't think that this is a putative (dare I say it?) perpetual motion machine. It looks like the fan on the left is connected only to the LED between the fans.

 

[hutchphd]

The efficiency of LEDs make them a far better choice for this experiment, particularly if you wish modest cost and size and want to use wind as the power source. They will be current limited by the setup and I think the chance of burning them out is very slight. Also they cost essentially nothing (in any quantity). The fact that they are polarization dependent need be remembered.
The other thing that works with LED because it is so low power and fast response is to use a rare earth magnet and a small coil to build a magneto. Lotsa fun.