Help with Latching/Reversing Relay for DC motor

Discussion in 'The Projects Forum' started by Trell, May 2, 2009.

  1. Trell

    Thread Starter Member

    May 1, 2009
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    I have made a motorized amp rack w/ a 42" LCD Screen to come out of a truck bed :D. I need to make a Latching Relay so a neg. 12VDC pulse will trip the relay and then when another neg. 12VDC pulse is sent it w/ reverse the output voltage for a 12VDC motor. I know I can buy one, but where is the fun in that.....I have NO or NC limit switches at both ends. Here are some Pictures of what I am doing
    http://www.ecosee.com/picturesnow@ecosee.com/TrellBuilt/

    Thanks for the help
    Trell
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Interesting project, Trell!
    I'll have to look at it later though, because I'm completely out of time this morning - I've posted some stuff on using relays to latch & reverse motors, but really don't have the time to search for them.

    Help me out to help you out by searching for 'em, and I'll get back later this w/e
     
  3. SgtWookie

    Expert

    Jul 17, 2007
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    OK, I see you have four relays in the mix there. Are those Bosch-type automotive relays?

    Are they SPDT? (Single Pole, Double Throw)

    Do you have a wiring diagram for your motor circuit thus far?

    If you don't have a schematic capture program, Cadsoft's Eagle Layout Editor is available as a free download from Cadsoft's site. However, a .PNG format scan of a simple sketch will do.
     
  4. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,176
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    Just guessing: First pulse causes motor to turn CW untill stopped by a limit SW; second pulse[ same SW ] causes motor to run CCW untill stopped by home limit SW ??
     
  5. Trell

    Thread Starter Member

    May 1, 2009
    11
    0
    Yes Barnard, You are right, but the only thing is that it blows the fuse when you have all relays hooked up??
     
  6. Trell

    Thread Starter Member

    May 1, 2009
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  7. SgtWookie

    Expert

    Jul 17, 2007
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    OK, I see. If you based the wiring for a reversing motor from that schematic, you'll have a problem.

    I'll have to re-visit this in the AM; it's getting late here and am tired after a long day at work.
     
  8. Trell

    Thread Starter Member

    May 1, 2009
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  9. SgtWookie

    Expert

    Jul 17, 2007
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    Looks like that should do it for you, Trell.

    Did you get it working?
     
  10. Trell

    Thread Starter Member

    May 1, 2009
    11
    0
    Hey,
    That SH.T worked I will post a little better wiring when I have time and get use to the Cadsoft's Eagle Layout Editor Thanks for everybody help and Sgt.Wookie keep up the great work. ooooorah!!!!
    Trell
     
  11. SgtWookie

    Expert

    Jul 17, 2007
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    Cool deal! :)

    Cadsoft's libraries won't have the blade-type relays in it, but there are several PCB-type automotive relays that you can use.
     
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