Hand cranked generator question

Discussion in 'The Projects Forum' started by pbalien73, Dec 13, 2008.

  1. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    I have a sculpture on hold that utilizes hand cranked magneto that the viewer must turn to see the interior of the work. The problem I first found was the magneto's would only generate enough power to light a small 12 volt bulb, that would be great but I need two 12 volt lamp bulbs. I was wondering if there exists a switch or relay that would work with the magnito to send power from a 12 volt battery when cranked, to the second more powerful bulb. Sorry if this doesn't make sense I am very uneducated when it come to electronics parts and verbiage. Thanks in advance for your time.
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
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    You might consider using two 6v lights wired in series instead of a single 12v lamp.
     
  3. floomdoggle

    Senior Member

    Sep 1, 2008
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    Try using a flywheel. And what is the output of the generator? A simple gearing system might preclude your need for an electronic circuit. Also, a hidden power source might be used. Museums use what you are thinking. Try asking your local museum, they'd probably be happy to help.
     
  4. Audioguru

    New Member

    Dec 20, 2007
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    Incandescent light bulbs waste almost 90% of the power making heat instead of light. Use two bright LEDs in series with a calculated current-limiting resistor or current regulator.
     
  5. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    Let me explain a bit further just for clarity. The work is a two part diorama with the surface being lit with night light strenth bulb (4watt) and the bottom section (a cave) being lit with a pretty bright led (unknown power rating). I would be fine with LED for top section but have no idea of power rating. If you can give example of LEDs in series (power rating) and how to use this resistor you speak of, I'll greatfully give it a shot. Thanks very much for your time.
     
  6. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    I'll pick up 2 6 volts and give that a try. Thanks
     
  7. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    Alright, here come my ignorance:) Whats a flywheel? No idea on output of generator (even if I had a tool a probably couldn't read it). I want to use a hidden 12 battery for surface light. Most of my work is based off of museum display and presentation. No local museums here, I'm on my own.
     
  8. floomdoggle

    Senior Member

    Sep 1, 2008
    217
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    OK, maybe a flywheel isn't the way to go. If you can, attach a much larger disc, or gear to the handle, and a smaller disc or gear to the magneto, making the magneto spin faster, getting the most output (power) out of the magneto. Could you show us a picture?
    Dan
     
  9. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    Pic of magnito and artwork.
    [​IMG]
    [​IMG]

    Crank sticks out right side (sorry lefty's). I have three of these built waiting for power supply resolution. I don't want power cords sticking out, thats why its a DC system. Thanks for your help.
     
  10. floomdoggle

    Senior Member

    Sep 1, 2008
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    Try radioshack.com. Look under relays 12V. Do both lights need to be on at the same time? If not use a battery for the first always on light and the magneto for the second.
    The relay circuit is simple.
    Dan
     
  11. beenthere

    Retired Moderator

    Apr 20, 2004
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    Have you considered just having the crank turn a load? The light would simply turn on while the crank was moving. If nobody can see the wires, it's all magic anyhow.
     
  12. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    Yes, I would like the top light to only come on when crank is turned to light bottom section. I bought a relay at radioshack (the store) but the one I got didn't work for me (i'm sure I bough the cheapest). I'll try the website maybe they have a better explanation of what I need than the idiots at the store trying to sell me a phone:)
     
  13. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    Please tell me more. What do you mean by a load? I get one light with the crank now but not enough power for strong top bulb.
     
  14. beenthere

    Retired Moderator

    Apr 20, 2004
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    That the crank just turns some mass that makes it feel that the person is doing useful work. It would not actually generate the electricity for the lights.
     
  15. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    Thats fine as long as the lights come on when the crank is turned. How would I make that happen? Is there a 12volt powered switch that would turn on the power supply?
     
  16. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,172
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    Sorry for more questions, but: what light is the generator now driving? We have a 12V bulb,4Wbulb,&a LED. Assuming the 12V bulb is 4W then you have about 300 mA available; if so you can light 10 strings of 3 bright LED's @ 30mA,4V ea. Each string needs 300Ω resistor 1/2 W. Is the gen. DC?;if not ,need full wave bridge rectifier. If you still need battery it can be switched with a MOSFET and a few resistors. First need the ans.
     
  17. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    No problem I need to be asked the questions, so I know what to ask myself. Honestly the main bulbs in the lower half are unknown. I ran them without checking (bought a bunch in a bag at flea market) but I believe they are 12 volt as the generators kill the 6volts and even some of the RS 12 volt 30ma have been blown if I crank too hard. The top light is a 12volt as well but came from vending machine and wont light up with crank generator but will with 12 volt battery. Is there a cheap and easy way for me to figure out the power of the handcranked generator? Looks like I need to redue the set up with help from the message board.
     
  18. floomdoggle

    Senior Member

    Sep 1, 2008
    217
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    The cheapest and easiest way would be to be stick both output wires on an exes tongue while you crank as furiously as possible. Then see how high they jump. LOL.
    But seriously, folks... Get a multimeter from your local electronics store. Get the cheapest one possible, and not a digital. For your applications, you do not need more than the basics, unless you want to learn about electronics. Which as an artist, musician, carpenter, and all around good-guy myself, I highly recommend. The uses are endless.
    Besides, who wouldn't like to hang out with these guys on AAC? Come on over to light side, we'll be waiting.
    Dan
     
  19. pbalien73

    Thread Starter Active Member

    Dec 13, 2008
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    I'm on it. Once I get one I'm sure I'll have fresh questions. What brand model should I buy as a newbie? Thanks everyone for all the help:D
     
  20. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,172
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    While you are procuring a multi-meter, might pick up a low wattage soldering iron, some fine guage 60/40 rosin core solder, some 24-28 ga wire,& some 3/32-1/8 in. heat shrink tubing. A few known V,W lamps might help. Automotive types as # 161,14V,.19A,1CP,2.66W;#194,14V,.27A,2CP,3.78W;#168,14V,.35A,3CP,4.9W.These are wedge base,fold down the contact wires and solder on some wire leads.When you are measuring voltage of magneto[AC?, DC?],measure with a load &without. Do you have some LED's to play with?
     
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