Wind generator?

Discussion in 'Electrical' started by echotraveler, Mar 5, 2009.

  1. echotraveler

    echotraveler Member

    Hello friends,

    i just bought a set of Reelight sl120's

    they are pretty nice lights that work without batteries, and make very little resistance.

    so i was looking on ebay for magnet generators and found this small wind should have very little resistance and provides a voltage output at 620 rpm was 12.31 VDC, 22.22VDC at 1100 rpm, 35.6 vdc at 1720 rpm and 48.5 vdc at 3100 rpm.

    has anyone tried changing a dyno for one these?
    is like and alternator i would think..

    heres a link to ebay:|66:2|65:12|39:1|240:1318|301:1|293:1|294:50

    Attached Files:

  2. SimpleSimon

    SimpleSimon Active Member

    Interesting. Hook one up to serve as an electric starter for an engine, and let it run as a generator once the engine is running. Plenty of power for a set of lights.
  3. mabman

    mabman Member

    A clever fellow up in AK came up with this using a similar generator to run his electric hub motor. If you could get the get the shaft to turn parasitically off the engine and get the rpm's right or rectify it somehow no doubt you could charge a battery or run lights direct. In fact you could probably run a microwave off one slightly bigger with an inverter. bikegenset.jpg
  4. skyl4rk

    skyl4rk Guest

    It will produce plenty of power for lights, the issue will be that it is DC, and the voltage depends on the rpm. If you are charging batteries, the changing voltage will be a problem that can be solved but not simply or easily.

    Here is a build using a slightly smaller permanent magnet motor.
  5. duivendyk

    duivendyk Guest

    To charge a 12 V battery would take something like 1200/1500 rpm ,might be good for up to 5Amp.could be used on HT engines with internal reduction of 4 to 1. A buckpuck constant output current regulator could be used to run LED's or charge a battery (battery voltage does not matter). Look up
  6. loquin

    loquin Active Member

    You sure about the buckpuck for the battery? Since it's a constant current source, as the battery 'resistance' increases as it becomes fully charged, the output voltage would increase until it exceeds the gassing voltage of a lead-acid battery, I believe.
  7. duivendyk

    duivendyk Guest

    You are quite correct in that regard, some other means needs to be provided to either limit the battery voltage or to provide an indication that the battery is being overcharged.The buckpuck by itself is not a complete solution.It has the advantage that it can handle widely varying input voltages,up to 36V I believe.It is my understanding that standard battery charging IC's are intended to operate from constant inputs,but I may be misinformed in that regard.The buck puck is nice that it is a constant, (but controllable) current source tailored to powering LED's which need this.If this generator does what it is claimed to do in terms of output current,7.5 Amps seems rather a lot for such a small unit, a battery would not really be necessary.Even a couple of amps would be adequate.Some coupling to mechanically disengage the generator might be useful,but there is nothing wrong with running with your lights on all the time,unless of course stealth is imperative.It appears to have ball bearings, so brush life would be the limiting factor.
    Last edited by a moderator: Mar 6, 2009
  8. lordoflightaz

    lordoflightaz Member

    I think that that generator will work for me. I am going to try it out at least. Just going to have to figure out a mounting bracket to put it above the SBP shift kit

    I have a solar voltage regulator that will work with this. (harbor freight, has the kit on sale again for $179, again) I also have an DC-AC converter that I can add in.

    Worst case I build a windmill. LOL
  9. duivendyk

    duivendyk Guest

    A pretty high rpm windmill at that, or else not much output.$179 is pretty steep for a regulator.You could get one for a third of that.What you would do with DC-AC convertor on a bicycle escapes me.I am sceptical of 7.5 Amp output,just the max current,but probably only 3 amps or so continuous.It's probably pretty durable if you don't overload it.
    Last edited by a moderator: Mar 6, 2009
  10. lordoflightaz

    lordoflightaz Member

    For $179 you get a bunch of stuff for a solar project. Solar Kit

    The "power center" has a place to connect the DC generator, instead of panels, 7 output jacks. So I just need to add a battery pack somewhere. I know that I can charge my nite rider light on the USB port, did it already on the kit that I have running The 12V lights would be fun if you need a little lighting while camping, just fire up the bike

    DC-AC is so I can plug in my expresso maker, web camera, small electric appliances, etc. LOL.
  11. echotraveler

    echotraveler Member

    be sure to take pics! i figured you guys knew a lot about it.
  12. duivendyk

    duivendyk Guest

    If you get it,first stick it on a drillpress and connect up to your powercenter& battery,to check it out.Would be nice to be able to monitor battery charge current and gen. output voltage at different speeds.Then you can figure out,what the drive ratio to it should be,watch out for excesive output voltage from the generator !
    As far as I can remember this motor has no internal cooling fan,so it could be prone to overheating,when operated continuously.The DC-AC convertor by the way is not part of the kit, I think.
    Last edited by a moderator: Mar 7, 2009
  13. lordoflightaz

    lordoflightaz Member

    You are correct the DC-AC converter is not part of the kit. I have a Targas, designed to power a laptop. It is relatively small, I have a bigger one that I use on the kit right now.

    I don't have a drill press, my neighbor does, but I don't know if he has an RPM controller on it. Will consider heat, probably can add an impeller to cool it if needed.
  14. duivendyk

    duivendyk Guest

    These things often have the chuck rpms posted on them,mine does.They typically run at either 1700 or 3400 (unlikely) rpm. a 1:1 pulley ratio would give you around 1700 which is in the ballpark
    Last edited by a moderator: Mar 7, 2009