Bistable DPDT Latching relay

Discussion in 'The Projects Forum' started by ColinSeggie, Mar 9, 2014.

  1. ColinSeggie

    Thread Starter New Member

    Feb 20, 2014
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    0
    New to the group and relatively new to electronic circuits, so please be kind!.
    I purchased 50 bistable DPDT latching relays for use with my model railroad the other day. They are to be used as a latching power switch to activate a 12v stall motor which in turn drives the points/turnouts. The circuit digram called for a 10 pin relay (two pairs of pins power the two coils). What arrived [from China] is an 8 pin-- the two coils share the same pins.My fault for not inspecting the product diagram.
    Attached is the circuit diagram -- is there a simple way to still use these relays?
    Or should I abandon the project and go back to using a DPDT toggle switch (on- on) The whole idea was to just use a simple push switch to toggle the motor one way and then the other, and the LED indicates the route!
    Doc Colin
     
  2. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
    2,503
    380
    hi,
    Do you have a datasheet for the 8 pin relay version, that you could post.?
    E
     
  3. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,553
    2,375
    Would this work for you, I have used it on occasion, only one P.B.
    Max.
     
  4. ColinSeggie

    Thread Starter New Member

    Feb 20, 2014
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    Hope this helps Doc Colin
     
  5. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,801
    1,105
    ?? I would suggest what you have is a single-coil latching relay. This requires the coil to be energised with one polarity to latch it and the opposite polarity to unlatch it.
     
  6. ColinSeggie

    Thread Starter New Member

    Feb 20, 2014
    7
    0
    Alec-- powering it up with a 9v battery and testing the relay side, it definitely has a double throw if you reverse the coil polarity. So whats the easiest way of reversing the polarity of power to the coil. From the product data they say its twin coil --see item 6-1462037-6 which is its part number on the package.
    Doc Colin
     
  7. ColinSeggie

    Thread Starter New Member

    Feb 20, 2014
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    Max-- your diagrams show multiple relay contacts! When I re-look at the "tortoise" it is or looks like a DPDT switch itself. Could I not use that to swap the polarity of the coil in the latching relay? Eish but I'm not sure how to draw/map it though!?!
    Doc Colin
     
  8. crutschow

    Expert

    Mar 14, 2008
    13,022
    3,236
    Here's an approach to use one of the DPDT relay contacts to reverse the coil direction. The capacitors are used to provide a momentary pulse from the push-button to latch the relay. The cap that is grounded by the relay contact just has its charge diverted to ground.

    PB Relay.gif
     
    Last edited: Mar 10, 2014
  9. k7elp60

    Senior Member

    Nov 4, 2008
    478
    69
    ColinSeegie,
    her is a simple diagram to latch an un latch the relay. My schematic shows
    9V, but any DC voltage connected to the DPDT relay will work.

    l
     
  10. ColinSeggie

    Thread Starter New Member

    Feb 20, 2014
    7
    0
    Many thanks for the replys, will try out the circuits given to me, and get back to you guys later.
    Thanks again in anticipation of success!:)
    Doc Colin
     
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