bicycle power

Hi.
I saw on youtube that you powered a 100 wat bulb with a bike and i would like to make that same thing but to power a battery,it seems like a swell idea i hope its not to hard

Hi rocktillyadrop

It is not too difficult to do, if you have a few simple skills, battery charging is perfectly possible if a little tiring.
I sell the plans on how to make it here (bottom of page)
http://www.gotwind.org/Purchase_Plans.htm

Ben.

are the instructions for charging a batterie on there?

Yes,
Also here on the forum if you are having any trouble.

Hi Gotwind
Does your bike plans tell you what type of motor/generator/dynamo to use ? I want to charge a 12v car battery but Im unsure whether a 6V dynohub would do the job ? Can you explain a little about compatibility of the voltage thing (I am a beginner) ie. is a 6v dynamo compatible with a 12v battery ? I find the voltage thing confusing and have had no luck on google.

Also, do you use a fixed magnet generator in your plans or could an alternator out of a car be used or a motor from a vacuum cleaner for instance ? I suspect that you use mainly fixed magnet ones because they need no power but are there other makes besides dynohub and where do I find them and how do I know what the voltage and wattage is on particular models ? I want to get the right dynamo first time if possible cos Im on a budget, but if I can find the dynamos for free in old equipment then that would be great too.
The thing that I want to do (at present) is just charge up 12v batteries so that I can use the power later on through an inverter. I am also gonna get an 18w solar panel soon.

Cheers!

P.S. Any recommendations for dynamos would be much welcome

Hi Steevo777.
Yes, the plans explain everything.
The dynohub will charge a 6 volt battery quite happily once the AC power is rectified to DC - 12v charging is pushing it to the limits.
Remember max power from the dynohub is only 5 watts, so its only a starting toy really.

Yes, the motors we all use are of the permanent magnet variety, unfortunately they are a rare item. the rpm has to be approx 400 to generate 12+ volts
The Ametek range of tape drive motors are often used, and can still be found in the U.S - eBay is a good starting point (include U.S in search)
Plenty of other posts on this subject if you do a search, from my homepage.
If you are charging batteries by pedaling you have a better choice of motors, as they can be geared up.

Ben.
http://www.gotwind.org/index.htm

steevo777

A Dynohub can produce 6 volts at 60rpm I think and also 12 volts at around 120rpm. I have spent a year playing about with the dynohub. You can use a voltage mulipling circuit to increase the voltage of the dynohub,but in electrical terms you don`t get something for nothing..

The current is reduced when you multiply the voltage..

Dynohubs can put out around 1 amp of current at 12 volts easily!!

I have got above 30 volts in high wind conditions!!!

I hope the below pictures inspire you to continue with your DYNOHUB project.

You might also find the freeplay dynamo mobile phone charger of use too.. it`s more portable than a bike and I think it could give out a lot of power.Ben has a link for this somewhere.


http://www.gotwind.org/freeplay_energy.htm

Hi Victor great photos

I can not understand how you manage to get the high voltages.

When under no load conditions I see up to 48 volts at 680 rpm, but when a standard bulb rated at 6V 0.5 Amp is used at 680 rpm, I only get 6.6 volts.
I thought that the people who designed the SA unit had been clever and made a unit that did not give higher volages as the revs increased. It must be remembered that when the SA units were being made only standard bulbs were used and if the voltage increased to much then these bulbs would burn out.
Or could it be that my SA units have very low outputs due to poor magnets.

Dennis

Thanks guys for replying. Some great pics there Victor and very inspiring :) I will probably buy a freeplay charger at some point. Thanks for bringing that to my attention.
Hi Gotwind, I have just purchased your bundle, so hopefully this will be sent in my email soon ?
I now need to get a decent dynamo, but I dont know enough about them. I suppose it might have to be "trial and error" in buying dynamos unless anyone can tell me which ones to avoid. There are alot of different ones on ebay (eg. ones out of old cars like land rovers etc).
I have ordered a "STURMEY ARCHER 3 SPEED DYNOHUB 1975 VERY GOOD CHROME" from ebay for just over £10. Should be here tomorrow I hope. Not sure if its any good but it will be ok for a starting point I think.