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Bicycle Generator to power El Wire

  1. Mar 31, 2012 #1
    Hello, I am a new member here and am having a problem as to finding the more effective way to power my el wire.

    For those that don't know el wire is a thin copper wire coated in a phosphor which glows when an alternating current is applied to it. My goal is to wrap my bicycle in about 5 metres of el wire and then power it using only the motion of the bicycle.

    The el wire will be powered by a 12v dc inverter that would create 105vac at 1000hz, my problem however is generating that 12v. Would I be able to use a 12v brushed dc motor rubbing against the side of the wheel to generate the 12v needed for the inverter?

    The motor I was looking at was:

    MOTOR 12/24V 4700/10000RPM 0.2A REVERSIBLE.

    Would a stepper motor be a better alternative? such as STEPPER MOTOR 12V 36R.

    Along with that here are some more specifications regarding el wire.

    The efficiency of the wire peaks at 100VAC but is still acceptable as low
    as 60VAC and starts tapering off above 120VAC.

    Power consumption is higher at higher frequencies. It seems to average
    200mw/meter.

    Current consumption is averaging around .002 Amps per meter.

    Any help would be greatly appreciated.
     
  2. jcsd
  3. Apr 1, 2012 #2
    I suppose it wouldn't work as a DC motor would produce and AC output making it not work in the inverter. I guess I could take the AC output and run it through a transformer to get the required 105VAC.

    Can anyone recommend a good DC or Step motor to use as a generator assuming I will be pushing the motor at 150-200rpm.
     
  4. Oct 16, 2013 #3

    meBigGuy

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    Gold Member

  5. Oct 17, 2013 #4

    NascentOxygen

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    Staff: Mentor

    Turning a generator makes the bike a lot harder to pedal when there is much current drain from that generator. You will tire faster. [Pun, get it?]

    While the EL wire probably won't draw much current, the typical inverter may use a bit (unless you build your own low power high efficiency unit.)
     
  6. Oct 17, 2013 #5

    sophiecentaur

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    Unfortunately, you don't get anything for nothing. As meBigGuy wrote, you will only get good results if you use a really good design - i.e. a commercial one. DC motors are really not very good as generators. You need a brushless alternator, which is the basis of the old fashioned bicycle dynamos (dunno what they do these days but old ones must be available). These produce AC, which is what you want, in fact. I guess you could try using a mains transformer, connected backwards, directly to it, to produce your 100V from the few volts from the dynamo. That will be much more efficient than a cheap inverter (and probably free, out of an old radio or cassette player). You should be a bit careful with this, of course, but you are unlikely to give yourself any more than a tickle. It will stop when you stop the bike, of course - but it was always that way. A Multimeter would be useful, to check on the volts you are getting. You wouldn't want to over drive the EL wire. I am not totally sure that the dynamo output would be at a high enough frequency until you get up to speed - but mine didn't flicker much so it must have been in the right ballpark.

    As you say, you need about 200mW per metre of EL wire, which isn't a lot but I would imagine you would need a fair length for it to be at all impressive. I remember it being very hard work, pedalling to keep my four cycle lamps alight and they were only a few Watts total. (Yes, it was overkill but I could be seen!)
     
  7. Dec 10, 2014 #6
    Thank's for all the help guys. I know I'm a bit late with this post but I just wanted to show you how the finished design looked. I opted to go with battery packs instead of a generator as it allowed for a much cleaner look and didn't limit my pedal output.

    This picture was taken under a streetlight at night.

    http://imgur.com/FGtH4bW
     
  8. Dec 11, 2014 #7

    meBigGuy

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    That's a cool look. Does it blink? Advantage of blinking is the battery lasts longer.
     
  9. Dec 11, 2014 #8
  10. Dec 11, 2014 #9
    Yes, There are three set options, solid, slow blink, and rapid blink. I prefer to leave it as a solid colour since the El wire hums a bit and becomes much more noticeable once it is blinking.

    I will see if I can find a picture in complete darkness. What you end up with in a glowing frame that seems to be floating off the ground. I showed the picture under a streetlight to show the light intensity even with neighbouring light in the area.
     
  11. Dec 11, 2014 #10
    Looking forward to. Must be really awesome to see it in live in dark. Actually, I would never guess the photo was taken under a streetlight (without that remark I would think it was a daylight!)
     
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