Connect with us

Negative voltage tolerent relay ?

Discussion in 'Electronic Components' started by tof, Feb 16, 2005.

Scroll to continue with content
  1. tof

    tof Guest


    Does it exist some relay which accepts (is tolerant) a negative input
    voltage without modifying the contact. In fact I want to make a
    alternative signal go through a relay. Is is possible ? How can I do
    it ?

  2. Relay contacts are not polarity sensitive. They may have different
    ratings for AC versus DC, but they don't care aout polarity...
  3. So it is if it's a mechanical relay.
    But today there are also optoelectronical working "relays"
    which are also called only relays, sometimes without the hint that they
    are electronically/optically working (optocouplers in all kind of
    outputstages ("contact") varies from transistors to fets
    (junction- and MOS-Fets) to triacs and so on.
    In that case they are polarity sensitive.
    (there are also AC-Versions at input ("coil") and output)
    Maybe chris-tof means such a semiconductor-relay.

  4. The term relay is reserved for magnetic, mechanical contact type relays.
    The SSR (solid state relay) is called that in order to tell it apart
    from the mechanical relay. Other such things are _not_ called relays,
    but optoisolators, etc.
  5. Guest

    For the coil, you can use a bridge rectifier to
    "steer" the voltage, assuming you can tolerate
    the voltage drop. That "steering" would be
    needed on electro-mechanical relays that have a
    built-in protection diode.

    The contact(s) don't care about polarity.

    If you are not talking about an electro-mechanical
    relay please let us know.

Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day