using a 5 pin relay

Discussion in 'The Projects Forum' started by saurabh shandilya, Apr 16, 2011.

  1. saurabh shandilya

    Thread Starter New Member

    Oct 15, 2010
    sir, i am completely newbie with the relay. My relay is with 5 pin
    2 on one side and three on one side...
    A,E on left side and B,C,D on right side..
    A and C are shorted by default...

    so kindly tell me across which pins i should supply the voltage so that the relay action takes place..??
  2. strantor

    AAC Fanatic!

    Oct 3, 2010
    If A&C are shorted, then likely that's probably your Normally Closed contact. I would assume per the lettering, that B would be your Normally Open contact, leaving D & E as your coil. Test the resistance between D & E. If it is a number (EX 50Ω) vise open or shorted, then it is indeed your coil. If you were to post a part number then you could get a more definitive answer. Or you could just google said part number yourself and look to the data sheet for the answer.
  3. John P

    AAC Fanatic!

    Oct 14, 2008
    Unfortunately, unless you find a way to look it up in advance, you won't know what the rated voltage for your relay coil is. And if you just play with it at random, it either won't operate, or you risk burning it out. You could look at your relay, and look at specs for others of similar size, and assume that the coil takes the same amount of power, but it's not the best way to do it.

    By the way, there are a few relays around which have a diode in series with the coil. (Yes, I said series.) So you'd have to know how much voltage to apply, and which way.
  4. SgtWookie


    Jul 17, 2007
    Some relays have a diode in parallel with the coil. Those can be difficult to figure out which way the current is supposed to flow. If you get it backwards, you'll fry the internal diode.