A hand for a noob with a timer for a car alarm

Discussion in 'General Electronics Chat' started by federicoaroca, Apr 7, 2014.

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  1. federicoaroca

    Thread Starter New Member

    Apr 7, 2014
    Hello world. I'm new here and I would like to start learning about electronics. It's something that fascinates me, but I know close to nothing about it.
    Last week I installed an alarm on my car by myself and I got it to work perfectly.
    Now, what I'd like to do is to install a cellphone in the car, take the signal from the lights that flash when the alarm is triggered and use it to dial my phone number by using the speed dial function on the phone that will be in the car.
    So far I have the following:
    - firstly, the signal from the alarm is a 12V DC current that is intermintent. It is on 1 second and off 1 second. There, I figured I could use a reservoir capacitor in order to have a (almost) constant signal.
    - that signal would operate a relay that will make a connection between the two contacts on a number key in the cellphone, so that after 3 or 4 seconds, the speed dial would call my number.
    - What I'd need is that the relay work for no more than 5 seconds.
    - After that, I'd like for the circuit to wait for about 1 or 2 minutes and start over.

    The end result would be:
    the car alarm is triggered and the car lights will flash (one second on, one second off) continuosly. Once the lights start flashing, helped by the capacitor, the relay will hold a number key in the phone's keypad, which will make it call me using the speed dial feature in the car's phone.
    After that, the relay will disconnect (the key in the phone will no longer be pressed); it will wait a minute and call me again (as long as the alarm is still active).

    I found here http://forum.allaboutcircuits.com/showthread.php?t=76837 in the first post of the thread, something that I think is what I need for the 5 seconds hold of the button. What I need now is the part where it waits a minute before calling me again.

    Would you be so kind to help me?

  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    Automotive projects are forbidden here, so no doubt this thread will be closed, sorry.
  3. federicoaroca

    Thread Starter New Member

    Apr 7, 2014
    Thanks for the reply. I'll try somewhere else.
    I wasn't aware of that. Perhaps it's because of my being new to electronics that I didn't realize that alarms, cellphones and timers don't qualify as "electronics".
    Thanks anyway.
  4. jimmiegin


    Apr 4, 2014
    hey man it would not hurt to try again somewhere and omit the car part maybe??? Say maybe some other idea that would require you to have this kind of set up? all the best [​IMG]
  5. Georacer


    Nov 25, 2009
    It's not because they are not considered "electronics". It's because the owners of the site have chosen not to host, among other things, automotive topics, as you can read in the Terms of Service.

    You may find answers in one of these sites (http://forum.allaboutcircuits.com/showthread.php?t=54400)

    Do not try to post the same question in this site undercover. It is painfully obvious.
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