Alarm Siren & Relay Help

Discussion in 'General Electronics Chat' started by G4M8L3R08, Dec 27, 2014.

  1. G4M8L3R08

    Thread Starter Member

    Dec 27, 2014
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    Hi guys & gals,

    Im completely new here so I hope I don't break any rules the first time I post.....

    I currently have 2 properties at the moment which is proving a pain as one of them isn't in the best of areas.

    I have a Yale HSA6000 alarm system in the loft so I decided to fit it to the said property. It has one wireless siren which isn't the loudest if im honest. It runs on 4xD cell 1.5v batteries, the idea is not to set it off if you want to conserve the power. I do have a spare siren and empty siren housing which I would like to put together and run from the wireless one, with a separate battery inside of course.

    My question, could I use the siren output on the wireless alarm, connect it to a relay which would complete a second circuit and set off the second siren? the wireless siren is also programmed to stop in accordance with the LAW so would the relay disconnect when the siren stopped?

    Thanks in advance
     
  2. MrChips

    Moderator

    Oct 2, 2009
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    In theory, yes, you can do as you said.

    The devil is in the details.

    You will have to find out what kind of signal, current and voltage is supplied to the siren. Then you will need a relay or a circuit to drive the relay that can be triggered from the siren signal.
     
  3. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
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    What do you mean by "the siren output on the wireless alarm" ? Is this a switched power feed to a self-contained siren or is it an audio signal that just drives a loudspeaker?
     
  4. G4M8L3R08

    Thread Starter Member

    Dec 27, 2014
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    It is a stand alone 6v siren, I popped the meter on just to make sure its 6v that is coming out. Would it be possible for someone to recommend some components or a quick circuit diagram please, ideally with the said relay from Maplin, I live local to one. As you can guess Im no electronics expert so my idea of how it would go is bellow, sorry for the poor paint effort.

    upload_2014-12-27_16-59-59.png
     
  5. blocco a spirale

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    Jun 18, 2008
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    That looks like it should work but you should also add a 1N4001 diode across the relay coil with the band to the + side.
     
  6. MrChips

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  7. G4M8L3R08

    Thread Starter Member

    Dec 27, 2014
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  8. MrChips

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    When they say "change over contacts" I assume that to mean SPDT.

    Either relay would work. The first one I mentioned appears to have longer pins for you to wrap around a wire connection.
     
  9. G4M8L3R08

    Thread Starter Member

    Dec 27, 2014
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    Ok, so the primary siren is 6v but the secondary im fitting is 12v. Just to make sure iv got this right, I need a 6v relay which is going to be switched when the 0v becomes 6v which will close the circuit for the 12v siren. correct?
     
  10. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
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    Correct.
     
  11. G4M8L3R08

    Thread Starter Member

    Dec 27, 2014
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    Thanks very much
     
  12. G4M8L3R08

    Thread Starter Member

    Dec 27, 2014
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    One last question, if I were to run this from a PSU, how would I add a lead acid battery to take over if the power went out?, would it be as simple as connect a trickle charger to the battery and just spur from the joint?
     
  13. G4M8L3R08

    Thread Starter Member

    Dec 27, 2014
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    Could I also pick your brains again please, I am wanting to do the same for my other property and connect an additional siren to the existing wireless one. Once again its 6v 4xD cell but a bit more complicated. the output that goes to the sounder isnt the same, I have put the meter across it and its showing 14.26v AC when the siren is active and 0 when inactive, how would I go about doing this one?
     
  14. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Use a small bridge rectifier on the signal followed by a solid state relay or Opto isolator to drive a 2n7000 fet to switch the siren.
    Max.
     
  15. BReeves

    Member

    Nov 24, 2012
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    I would drive a transistor, 10K to base of a 2n9570 and let the transistor pull a relay in. Just another way to skin a cat but without depending on the first siren's ability to deliver much current.
     
  16. G4M8L3R08

    Thread Starter Member

    Dec 27, 2014
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    Could you build me a maplin part list and a basic wiring diagram please? would really appreciate it. I can pick the parts up first thing and get it all soldered up. I just want the relay to close a 12v circuit that will enable a standalone 12v siren and 12v red flashing led, then disconnect once the original siren once it stops (one thats currently showing 14vac).

    The existing siren thats running from 4xd cells at 6v I doubt will be supplying much current, also would rather not draw too much juice from the existing one since its only running on 4xd

    Thank you all for the replies
     
  17. MaxHeadRoom

    Expert

    Jul 18, 2013
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    What is the current for the 12v siren?
    Max.
     
  18. G4M8L3R08

    Thread Starter Member

    Dec 27, 2014
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    250ma maximum
     
  19. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Something like this maybe.
    Max.
     
  20. G4M8L3R08

    Thread Starter Member

    Dec 27, 2014
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    Would you be able to tell me exactly what I need from maplin please. sorry for being a pain
     
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