Need help

Discussion in 'The Projects Forum' started by Gone50to, Aug 29, 2008.

  1. Gone50to

    Thread Starter New Member

    Aug 29, 2008
    3
    0
    anyone know where to buy a small electromagnet that switches its polarity on and off?
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    Can you give more information and what exactly do you want
     
    Last edited by a moderator: Oct 12, 2015
  3. Gone50to

    Thread Starter New Member

    Aug 29, 2008
    3
    0
    I need a small electromagnet in a cylinder shape for contact. I need the polarity to be switched easily but with strong fields. Is there any place that sells them or do i have to make one. I need there to be a switch somewhere to switch the polarity very fast back and forth. Is there any way to make a mini spring contact where when the piece of metal is pushed down onto the other piece it can switch polarity.
     
  4. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Do you have particular dimensions in mind? Small might be 2" long, 1" diameter. It could also be 1" long, 1/2" diameter. Or larger, or smaller. It's a relative thing.

    Switching polarities is easily done with a DPDT (double pole double throw) switch or relay.

    There are a number of places that sell electromagnets. Alternatively, you could buy a solenoid of suitable voltage.

    [eta] Try this Google search; I received nearly a million hits:
    http://www.google.com/search?hl=en&q=Electromagnet

    How fast is very fast? 100mS (1/10 second)?

    Well, you can get microswitches that are controlled by a lever; the microswitch contacts could power the coil of a DPDT relay.
     
    Last edited by a moderator: Oct 12, 2015
  5. Gone50to

    Thread Starter New Member

    Aug 29, 2008
    3
    0
    could somebody draw me a diagram and parts list? 2" long 3inch diameter. Where do buy a double pole trhow switch etc. I need the small electromegnet,switch polarity,onpoff power and polarity switch buttin thanks!
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    If all the solenoid does is operate a switch, then a relay will do that more easily.
     
  7. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    There is an electromagnet of those approximate dimensions on this page:
    http://www.apwcoinc.com/e-magnet.php
    EM300, 3" diameter 1.5" long, 300 to 400lb holding force.
    In DC, they're available for 3V, 4V, 6V, 12V, 24V, 90V, 110V, 220V.
    DC power rating is 15 Watts.
    Prices range from roughly $90 to $140, depending on options.

    Did you have a suppy voltage in mind?

    Is this in the price range that you were considering?
     
    Last edited by a moderator: Oct 12, 2015
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