Differences in relays

Discussion in 'General Electronics Chat' started by Landon, Jun 4, 2009.

  1. Landon

    Thread Starter New Member

    Oct 3, 2007
    9
    0
    Hi guys,

    What's the difference between a standard relay and those mercury wetted relays? Can anyone assist? I'm building a circuit which require the mercury wetted relays, but i'm having trouble obtaining it. Anyone can assist on this?

    Thks
    Landon
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,346
    Hello,

    Electronic parts with mercury will become less and less.
    Mercury is not allowed any more, due to the bad influence on the envirement.
    The only place you will find them is in surplus stores.
    Here is a link for an example:
    http://www.surplussales.com/Relays/mercury.html

    Greetings,
    Bertus
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    The mercury was there to keep the contacts from wearing out during normal operation. You will not find mercury wetted relays because of environmental concerns, as Bertus said.

    Get a relay that can handle the voltage and current, and is in a similar package.
     
  4. eblc1388

    Senior Member

    Nov 28, 2008
    1,542
    102
    I would have to disagree with comments by others to just use a common relay or a reed as replacement.

    If the original designer choose to use a mercury wetted contact then you can "simply" replace it with a contact that doesn't bounce and one that have consistent and stable contact resistance between operations.

    Unfortunately, the only type of contact that does not bounce is, as you should have already guessed by now, the mercury wetted contact.
     
  5. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,346
    Hello,

    What is the application?
    Why do you need the mercury wetted contacts?
    Is a solid state relays possible?

    Greetings,
    Bertus
     
  6. russ_hensel

    Well-Known Member

    Jan 11, 2009
    818
    47
  7. Landon

    Thread Starter New Member

    Oct 3, 2007
    9
    0
    Hi guys

    Thks for all the replies. Appreciate it. I'm building a circuit to simulate a spike.
    The selection for mercury is due to it does not bounce. Unfortunately, it seems rare. I'm trying to look for alternative and substitutes to it but i'm having some difficulties.

    Attached below is the circuit. on the extreme right is the mercury wetted relay.
     
  8. bertus

    Administrator

    Apr 5, 2008
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  9. Landon

    Thread Starter New Member

    Oct 3, 2007
    9
    0
    Hi Bertus, it's 730 in the morning and you replied me! Wow. Thks alot. I think your suggestion might work. I'll try it out. Thank you so much. Love this forum.
     
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