Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: GrajScience on 13/01/2016 17:50:54

Title: How do I build a dynamo with a specific output voltage?
Post by: GrajScience on 13/01/2016 17:50:54

I'm having a hard time finding information about dynamo construction.

I know how to build a simple generator.  Thanks 8'th grade science.

What I am having difficulty with is finding out how to build a dynamo with a specific output voltage.

I can buy one on the internet. Hand Crank 110v ac generators are all over the place.

But I want to build one with my kids in the garage.

If someone could just help guide my questions, so that I know how to ask the question in the proper format to get me to the information I am looking for, that would be awesome.

Is it primarily based on the RPM's?  The number of magnets? The number of windings?

Any help would be appreciated.

Thanks!

Title: Re: How do I build a dynamo with a specific output voltage?
Post by: RD on 21/01/2016 00:09:23

You need a voltage-regulator circuit ...

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fcdn.instructables.com%2FF4S%2FO6CH%2FGS3BEFTV%2FF4SO6CHGS3BEFTV.MEDIUM.jpg&hash=6a1890fef191dccc582b41ce641efae3)
http://www.instructables.com/id/Voltage-Regulated-5-V-Bicycle-Dynamo-Light-USB/

NB: Human-powered electricity is ecologically unsound ... http://www.cnet.com/news/human-energy-harvesting-a-very-silly-idea/

Title: Re: How do I build a dynamo with a specific output voltage?
Post by: alysdexia on 23/01/2016 06:17:39

https://en.wikipedia.org/wiki/Dynamo > https://en.wikipedia.org/wiki/Faraday's_law_of_induction#Quantitative.

You'll need to go by the rated B strength in gauss or tesla if you don't own a meter, then take the sectional area of the wire itself (I think), rather than the loop, to find flux.