Cheap Alarm

Discussion in 'General Electronics Chat' started by logicrules, May 8, 2010.

  1. logicrules

    Thread Starter Member

    May 3, 2009
    16
    0
    Hi, All About Circuits,
    I ran into a rather interesting situation; I purchased a bike alarm, and after some playing with the housing, it worked for about 9 mos., and the other day it quit.
    I know it was a cheap alarm but it worked good, daily. I had to go somewhere.
    I turned it off and went for a ride, and tried to set it when I got home; there was no sound.
    OK, the battery finally went, so I went to the store and bought a new one, 9V.
    I installed the battery, and went on to reset it, no sound. AHA, I thought, loose wire; so I opened it to find all intact. Now what? And here it gets interesting…
    When I purchased the alarm, and it arrived, I tried to install a 9V battery and it would not fit. ****! But do not despair. I have enough tools to make an attempt to make the battery fit. But… I informed the seller of the situation, and they said they will send me a new one with the guarantee they will test to make sure it will fit. Right! They did send a new one. The new one arrived, and I sucked up the loss and took to making the housing have the proper sizes. And it worked for 9 mos., or so.
    So I got out the replacement and tested it with the new battery (tested: 9.48v, cheap store, cheap battery.); it sounded but so low that it had to be placed near to my ear to hear.
    Of the various things that may reduce the sound on a device at this point sounds to me like a temperature problem I have in El Paso, TX.
    Now, I am asking for help in resolving this problem so I may learn more along with the rest of yooz.
     
  2. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    What is the brand and model of the alarm?

    Do you have a link to where you bought it?

    If the battery didn't fit, It may have been the wrong battery. It could have been designed for a different battery.

    Did it have the standard 9v battery connector on wires, or was it an integrated battery contact?
     
  3. logicrules

    Thread Starter Member

    May 3, 2009
    16
    0
    The alarm definitely, uses a 9V battery.
    There is a seam around the battery/Piezo area which can be lifted out with a small screwdriver. I used a high speed drill to remove almost all of the section separating the battery from the circuit. I then placed a plastic sheet cut from bubblepak in its place.
    While I was in there I also removed the ball bearing (which had separated from the Piezo wafer), and put a small dab of solder in its place.
    And so it has been functioning, up to now.
     
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