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This is awesome. What are you using for the control circuit? Any
chance you could use an RCX?
KL
In lugnet.build, Christopher Snead writes:
> Hello, everyone!
>
> I've finally finished a project for my Physics class:
>
> http://www.brickshelf.com/cgi-bin/gallery.cgi?f=8857
>
> This device suspends small, ferromagnetic objects in midair using an
> electromagnet and a beam of light. The beam of light shines on a
> phototransistor, which translates via a control circuit into current to the
> electromagnet. An object in the path of the beam reduces the amount of light
> incident on the phototransistor. As the object falls, more light reaches the
> phototransistor, and the magnet gets stronger; as the object moves towards the
> magnet, less light reaches the detector, translating into a weaker magnetic
> field. The object reaches equilibruim, and hangs in midair!
>
> I used Lego to build the frame and the light shields. As it turns out, the
> LED's and the phototransistors fit quite well into the technic holes. Using
> Lego saved quite a bit of time, as opposed to machining an apparatus. It also
> allowed me to play with Lego while working on my final project! ;-)
>
> Sorry to all of the Purists out there - Lego does not yet make electromagnets
> or Phototransistors or op-amps. Don't worry, I'll be back to building pure
> Lego mecha in no time...
>
> Chris
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Message has 1 Reply:
 | | Re: Magnetic Levitator
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| (...) I think that it would be possible to use an RCX. I used four op amps in my circuit; the first amplifies the signal coming from the phototransistor, the second differentiates the signal, the third takes the difference of the proportional and (...) (23 years ago, 7-Dec-01, to lugnet.build, lugnet.general, lugnet.robotics)
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Message is in Reply To:
| | Magnetic Levitator
|
| Hello, everyone! I've finally finished a project for my Physics class: (URL) device suspends small, ferromagnetic objects in midair using an electromagnet and a beam of light. The beam of light shines on a phototransistor, which translates via a (...) (23 years ago, 6-Dec-01, to lugnet.build, lugnet.general)
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