PCB Relay question

Discussion in 'General Electronics Chat' started by zeebow, Oct 26, 2007.

  1. zeebow

    Thread Starter New Member

    Oct 26, 2007
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    0
    Hi All,

    Are there any PCB type relays which as soon as they dedect a small voltage pulse at their input, will switch on a custom circuit and leave it on, while as soon as they detect a second voltage pulse at the input will simply switch off the circuits.

    Maybe its not a relay I should be looking for. Any suggestions?

    Thank you
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    You might be able to find an impulse latching relay that will work for the application. The magnitude of the voltage pulse and the nature of the load (volltage and current draw) will have lots of influence on the relay.
     
  3. thingmaker3

    Retired Moderator

    May 16, 2005
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    Depending on your specific requirements, you might consider using a JK flip-flop.
     
  4. cumesoftware

    Senior Member

    Apr 27, 2007
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  5. beenthere

    Retired Moderator

    Apr 20, 2004
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    Beg to differ about the relays. Panasonic makes a variety of single coil latching relays that operate from 1.5 volts up to 24 volts. Look for the ASX2101 - ASX21024 series relays. Digi-Key carries them. They also come in SMT styles. There are several other series by Panasonic that can carry more load current.
     
  6. cumesoftware

    Senior Member

    Apr 27, 2007
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    Do they unlatch with another signal, as said by the thread opener? Latching relays can be easily made with a standard relay. You just feedback from the NO contact to the coil. Once a signal is applied to the coil, the coil will close the contact, which will feed the coil, and it is a latching relay. You can unlatch such relay by applying another signal. Only mechanical latching relays that have two coils are capable of that.
     
  7. beenthere

    Retired Moderator

    Apr 20, 2004
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    Yes they do -that is why they are specifically called latching relays. I am using a larger version to control lights in my basement.
     
  8. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    No but if you put a switch or contacts in series with the coil, you certainly can open a latched relay.
     
  9. thingmaker3

    Retired Moderator

    May 16, 2005
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    You can open a dual-coil latching relay with a second pulse. No extra switch is needed.
     
  10. cumesoftware

    Senior Member

    Apr 27, 2007
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    They probably have electronics, and so, they are relay devices, not relays.

    Exacly!

    Yes, but you have to apply the signal to the opposite coil.
     
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