12v,timer,delay shutoff,siren

Discussion in 'General Electronics Chat' started by cam366, Jun 21, 2014.

  1. cam366

    Thread Starter New Member

    Jun 21, 2014
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    I am wanting to have a siren turned off,12v.I have a radio shack,old school "photo eye" alarm,and it is ac.When the eye is blocked,by an intruder,the alarm triggers a 12v siren to go off.It will not stop until someone pushes the button on the back of RS unit.That is ok if someone was there,but nobody will be there,so if a bird sets it off it go on and on.I would like to wire something in that will shut off in an hour,or less,of my choosing.What I have found is timers that have to be set(digital),and if you have to set it when you feed it power,then it will not work,unless it has some sort of memory,of the setting previous.If it was like an ac timer,as soon as you started feeding it 12volt,it would run until it got to the shutoff time and then shutoff.It would not have to reset itself,someone would do that at that point(next day),thanks Dave
     
  2. inwo

    Well-Known Member

    Nov 7, 2013
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    Off the shelf, use 12vdc interval timer relay.

    A Time-on timer will also work. Use the NC contacts and latch the output to the input signal.
    The siren will follow the input to a maximum of the timer setting.
    Remove power to reset.

    Rereading post, you may want to use a time-on timer that resets your alarm after timer setting.

    You could make your own timer with a long range timer IC, but still may need a relay on output, for alarm reset circuit.
     
    Last edited: Jun 21, 2014
  3. cam366

    Thread Starter New Member

    Jun 21, 2014
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    I appreciate your help.I am not a big electronics guy,so that did not help me.The terning is where I get lost(I do not know the short terms).I will look up and read about the off the shelf item you suggested.thanks again Dave.I think it would be impossible to reset the radio shack unit without pushing that button,but I am ok with that.If a bird sets it off I do not want it to run all nite,thats all
     
  4. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Don't know where you're based, but in the UK alarms have to turn off after ~ 5 mins (I think). Otherwise annoyed neighbours are likely to take the law into their own hands and disable the alarm permanently :).
     
  5. inwo

    Well-Known Member

    Nov 7, 2013
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  6. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
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    Use the timer relay to reset the alarm, by using the contacts in place of the reset button, so when the alarm sounds the relay times out after the set period and operates the reset button.
     
  7. inwo

    Well-Known Member

    Nov 7, 2013
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    That would be best, but OP says "I think it would be impossible."
    Might be a keypad?

    The way I've shown will not retrigger.:(

    A repeat cycle timer would be on-off-on-off at selected period.
     
  8. cam366

    Thread Starter New Member

    Jun 21, 2014
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    I was looking at what you suggested already,but had not purchased.Was not sure it was correct.I purchased tonite,will know in a week if it works.It sounds good to me.The reset is not important,hopfully it scares them off for the nite,then I will reset eventually,and will know something triggered it.Will let ya know when I check it out,thanks again Dave
     
  9. cam366

    Thread Starter New Member

    Jun 21, 2014
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    Bought the timer delay relay.All it did was to delay the start of the power,by 0 to 60 sec.Thats not what I was looking for.I need it to come on immediately and stay on for a period of time ,then shutoff,thanks dave
     
  10. inwo

    Well-Known Member

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    Connect load thru the normally closed contact.

    Then load will be energized as soon as soon as power gets to timer.
    Load will turn off after time delay. Stay off until reset.

    [​IMG]
     
  11. cam366

    Thread Starter New Member

    Jun 21, 2014
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    I bought exactly what you sent me,just like the photo.Problem is to start,I have not got the 12v light(which I am using for a sample,without the noise)to come on.There is only instructions(diagram)which I don't understand.The timer/relay has 8 terminals.I think I have the power on right.The timer has a small light that comes on when the power is activated,then the timer which has another small light that comes on after the time set of five seconds,then the light is connected to two terminals,and it should come on when that second light comes on,but does not.I have moved those wires around those terminals,in every configuration I can think,and it does not come on.Mind boggling for me.I think I do understand to wire it in reverse,only,I do not want to proceed without it working in forward direction first.Hope that makes sense to ya.If it is possible for you to see that diagram on the side of the timer in that photo,you will understand it,I just don't.I am a trial and error guy,in this case anerror guy.thanks dave
     
  12. inwo

    Well-Known Member

    Nov 7, 2013
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    As you can see, power feeds thru timer just as before.

    After "time" contacts will open. Siren will stop.

    There is a small possibility that timer has a timed contact and an instant contact.
    Most simple timers do not.
     
  13. cam366

    Thread Starter New Member

    Jun 21, 2014
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    got the message,and could not wait to try it ,its been driving me crazy.hooked it all up like you drew it up.the light came on like it was supposed,and then went off,at several settings on the timer.great.this timer is for a max.60 seconds.that will be ok I guess,but I was hoping for a timer of max hour,then the crooks might leave,as opposed to hearing it shutoff,and go ahead and steal things.I will look for a timer just like this one only for longer time.I really appreciate this group site and you the champ of course.Thanks dave
     
  14. cam366

    Thread Starter New Member

    Jun 21, 2014
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    got that going good.Now ,I wonder if there is a 12v timer delay that can trigger,or turn on/or start an ac timer switch(mechanical type), then I can set it to an hour,or more if I like.thanks dave
     
  15. inwo

    Well-Known Member

    Nov 7, 2013
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    Same project?
    You have unused contacts that will trigger after your delay.
     
  16. cam366

    Thread Starter New Member

    Jun 21, 2014
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    unused contacts that will trigger the same siren again ?Which terminals are they,then I can play around with it.another question,same project.Will a niles ac-3,box,actually turn on an ac outlet,when you feed in constant 12v ? If thats the case,I will wire my 12v alarm into it,and when the alarm goes off,it will feed it,and start the old fashioned plug in timer,and stay on as long as i want.I can also plug a strobe light into it to go off at the same time.,thanks dave
     
  17. cam366

    Thread Starter New Member

    Jun 21, 2014
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  18. inwo

    Well-Known Member

    Nov 7, 2013
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    Terminal 5 & 9 will connect after time delay.

    Yes, the 12v to niles ac-3 will turn power on to the outlet.
     
  19. cam366

    Thread Starter New Member

    Jun 21, 2014
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    so you are saying the first set of terminals will go on for 60 seconds,and then the 5 &9 will go on for another 60 seconds ,correct ?thanks much for all your help,Dave
     
  20. inwo

    Well-Known Member

    Nov 7, 2013
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    No, the terminals you use now, stay on for 60sec after alarm. When those terminals open (after 60sec) 5 & 9 will close for duration of 12v alarm input signal. (until reset)

    In other words: 5 & 9 are the ones you first connected. They delay the out put signal.
     
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