bicycle generator

Discussion in 'The Projects Forum' started by douglas karugaba, Nov 9, 2010.

  1. douglas karugaba

    Thread Starter New Member

    Feb 8, 2010
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    hey..am working on a project were we are trying to creat a mini bicycle powered generator for a mini sized home stead. i need some bit of help, do u guys think using bicycle gears to soften on the cycling really does work!! becoz we have discovered that evn then the person would have to cycle faster thus the same situation. am using a car alternator to charge a 12v battery.. could anyone that amy have tried this give me some bit of advice!!
     
  2. marshallf3

    Well-Known Member

    Jul 26, 2010
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  3. wayneh

    Expert

    Sep 9, 2010
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    See my comments on the similar thread on this topic already underway.

    Bottom line: A very difficult project to get anything satisfactory. A reliable output of 50W into the load, from a normal rider, would surprise me as a terrific success. A small homestead needs maybe 2000W, maybe less on average.
     
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  4. PRS

    Well-Known Member

    Aug 24, 2008
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    Excellent project. Well worth doing. I take it you are talking about a stationary bike that drives a generator given the peddling of the pedals. And this energy is stored in batteries. You get exercise and you provide energy for your home. How cool?

    For a generator drive a General Motors alternator. Not a Ford alternator. I say this because GM (Delco) includes the AC to DC conversion right there in the unit. This machine puts out a DC voltage in proportion to its speed.

    I think you want to charge 12 volt batteries? Therefore you need about 13.5 volts output from your unit (ac to dc generator, which is combined in Delco units.) Getting your unit to charge 12 volt batteries means having 13.5 voltcharger.

    I will expound on this after I change the batteries in my mouse and keyboard units. But before I do that, let me elaborate a little here: You need high rpm from your bike pedals. And so, use a gear ratio that gets it done. Remember those old time record players that were cranked? Look into that technology.
     
    Last edited: Nov 9, 2010
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  5. John P

    AAC Fanatic!

    Oct 14, 2008
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    What gears will do is allow you to run the system with more speed and less torque, or vice versa, but you'll never get more energy out than you put in. I can't see a family doing enough sustained work to keep their house powered in the style we're used to, or even close.

    Years ago I remember seeing a news story about a man who wouldn't let his kids watch TV unless they pedaled a generator to power the TV set. He said he got the generator from an auto junkyard, and when he told the owner what he planned to do with it, the guy gave it to him for nothing.
     
  6. douglas karugaba

    Thread Starter New Member

    Feb 8, 2010
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    :rolleyes:i will most suddenly consider all those pieces of advice. we are running the project on trial and error modules. most certainly we should not bedone anytime soon.i will keep you posted on the progress.thanx
     
  7. vojnet

    New Member

    Dec 5, 2010
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    I have just registered here and one of the reasons are projects like this.

    I don't know why people always say that it is too hard, or too little power is produced. Nobody expects to power the whole house with a bicycle generator, of course. But, to have additional source of energy is fantastic, isn't it?
    I got the same reaction at one forum about vertical axis wind mill - many negative comments, saying it would not produce enough energy. The point is, you can build devices like this with very little money and have additional source of energy, or even a main one for some remote location. That is great!

    I have all the parts now for my vertical axis wind mill, but bicycle project is also something I will do when I gather some cheap parts.
     
  8. wayneh

    Expert

    Sep 9, 2010
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    Turning human food, our highest cost and energy-intensive energy source, into electricity is a ridiculous approach. You're effectively turning steak into coal. Whoopee. And while it's great to be encouraging, it's unforgivable to let someone work long and hard on something that will ultimately bring a big disappointment. Better to know upfront.
    Perhaps. VAWTs have some inherent problems, but also some advantages, chiefly installation options.

    But with any energy source, the analysis comes down to how much power you get from your investment. The test is simple: Could you ever convince someone else to buy your device for what it costs? Come back and tell us we're wrong once you've got the figures for your device.

    Until then, my money is on the accumulated wisdom of the folks who have gone before us. They say it's hard, and they can identify the physical laws that show WHY it's hard. These are NOT unexplored ideas. There's room for innovation, but it's important to acknowledge the challenge if one is to have a chance.
     
  9. iONic

    AAC Fanatic!

    Nov 16, 2007
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    If you have the bike, the alternator, and the battery, then you're going to get free energy and exercise quickly. As far as powering a small homestead, I doubt it. It may be sufficient to top off batteries from minimal uses, but to charge one from 12V to 13.5V will take a LOT of riding. Since it would be difficult to obtain the RPM's necessary to obtain a charging voltage for the battery, a boot/buck circuit may be necessary to increase the voltage at the expense of charging current. But without the voltage, you get no charging at all.

    Don't want to discourage you as I have a couple of identical treadmill motors that I want to use for generating power by means of bike peddles and arm power...my legs are too weak to do the job and I do need some cardio work. If I just top off batteries while getting the cardio workout then I'd be more than happy.


    iONik
     
  10. wayneh

    Expert

    Sep 9, 2010
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    Well, I understand the point but it's not technically true from an engineering standpoint. The energy is only "free" because we've already eaten too much and need a way to burn it off. If we're going to be exercising on a motor, we might as well reclaim some energy in a fun way. But that's a far cry from designing to use human energy as a significant source of "free" power.
     
  11. iONic

    AAC Fanatic!

    Nov 16, 2007
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    Whether you weigh 400lbs or 40lbs, exercise is good, and you'll be purchasing years of life at a great value!


    iONic
     
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