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How to wire LEDs through magnets?

  1. Aug 31, 2013 #1
    Hi guys.

    I'm an architecture student who is designing a lamp that will be made up of multiple, modular pieces of plywood. Each piece will be a hexagon containing 6 LED lights (one on each side). The idea is to have a base that plugs into a socket with a wall wart: I was thinking 12 volts AC. And the plywood pieces attach to the base and to each other with magnets. This enables the user to assemble and configure the light to his wants and needs.

    But I have never wired anything before... (Slight problem when designing a lamp haha.)

    Would there be a way to wire this thing so that when you connect a plywood piece to the plugged in base piece through magnets, the LED lights turn on? If so what would that circuit look like?
    I feel like their should be a way if there's a contact at each connecting point (magnet).

    I have no clue about electrical wiring or where to begin. So any help will greatly be appreciated.

    I found this lamp which is similar to what I am trying to do if this helps visualize my question at all:

    Here is another similar example:

    And another: http://www.hyperexperience.com/?p=1026

    I was told the LED module will need a current limiting resistor in it. Do I put one resistor in the first module that plugs into the current and thats it for the whole system? Or do I need a resistor in each module?

    Thanks for any help you can provide...
  2. jcsd
  3. Aug 31, 2013 #2


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    Staff: Mentor

    How much do you know about basic electronics? Have you ever taken a course on it?
    If not, and you lack practical experience in designing and building circuits, I HIGHLY recommend you find someone with experience to help you. A forum is simply not a good source for the kind of help you need. The last thing anyone wants is for you to electrocute yourself or start a fire because you don't understand the basics of electrical safety.

    That being said, I don't want to discourage you from using PF, I just want to make sure that any information you get from the forum is used safely.
  4. Aug 31, 2013 #3
    I've taken a bunch of extra physics classes in high school and a couple in college. I've done circuits before in those classes. But simple stuff: light bulbs in parallel or in series with a battery and a resistor. But I am a little bit lost when it comes to figuring out a circuit for my lamp idea. Once I do have a more clear direction, I am going to talk to one of the professors here to get it checked out before I start soldering wires together. But I need a basis before I go and talk to him. Which is why I though posting on this forum could get me started in the right direction. Starting with, is this at all something I could feasibly build?
  5. Aug 31, 2013 #4
    I was thinking that maybe a magnetic reed switch might do the trick?
  6. Aug 31, 2013 #5
    Neodymium magnets are coated with a thin layer of metal so they conduct electricity. When two magnets are stuck together a current can flow between them.
    To keep things safe I suggest you do your experiments with a 9V battery.
  7. Aug 31, 2013 #6
    Could I do something like this:
    12V +----|>|----|>|----|>|---/\/\/----+ R = 22 ohms
    12V +----|>|----|>|----|>|---/\/\/----+ R = 22 ohms
    where you have 2x3 array of LEDs per module? (for tests I would use the 9V battery and adjust R accordingly).

    Once I start putting multiple of these together, can the resistors all be the same in each module?
    And if I use the neodymium magnets as contact points, is there a risk of electrocution if someone touches them? Or is it fairly safe as long as they don't lick their fingers first? I don't want to kill anyone.

    Thanks for the help :) I appreciate it
  8. Aug 31, 2013 #7


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    Gold Member

    A hexagon is a six sided planar shape.

    So you envisign a flat pieces of plywood each cut into a hexagon shape, each of which would be a module, and your lamp will be made up of several of these flat hexagon shaped modules stuck together by magnets.
    Is that your idea?
  9. Aug 31, 2013 #8
    I'm going to use the CNC to mill these hexagonal pieces. They will have pockets in them to conceal the wires. On each of the outer sides there will be a magnet, on each of the inner sides (because the middle is cut out) there will be an LED light. My idea is that you plug the first one in and it lights up. Then you can add as many as you like in the configuration you like. And when you add a module, it lights up and the first one stays light up also. So the more you add the more light you get basically.
  10. Aug 31, 2013 #9
    they will have some thickness to them
  11. Aug 31, 2013 #10
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