Splitting a power supply?

Discussion in 'The Projects Forum' started by Greedy, May 5, 2016.

  1. Greedy

    Thread Starter New Member

    May 5, 2016
    2
    0
    Hi All, Newbie with a first post so please be nice :)

    My electronics is a bit rusty having not used it for a few decades - since school but I'm getting there.

    I am creating a 'door bell' for a warehouse which requires sound and light notifications and for the signal to be maintained for a loner period than the bell button is pressed. I have 2 separate timer circuits which each switch a relay: 1 powers a strobe LED circuit and it works fine, the second powers a sound generator and an amplifier. The sound generator works fine, as does the amplifier as I have tested them independently. they also work fine when connected one to the other but only when fed by independent power supplies - the generator fed from the Power Rail of the bell unit box and the amp by a separate bench power supply. However when I connect the amp to the Power Rail in the box then it does not work. It is not current drain issue as the amp only pulls 20milliamps max so I am assuming there most be some kind of issue with the sound generator and the amp being on the same power source - does this sound right? and if so, how can I split a 12v feed to provide 2 independent sources - ideally I don't want to have to plug in 2 separate power adaptors.

    Thanks.
     
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,769
    969
    Schematic?
     
  3. Greedy

    Thread Starter New Member

    May 5, 2016
    2
    0
    First is the schematic of the timer used to switch the power for the sound generator. Second it the schematic of the sound generator and amp.

    The +ve 9Vsupply is connected direct to the timer and amp circuits and via the relay (of the timer circuit) to the sound generator -ve are all common.

    Hope that helps. Thanks.

    upload_2016-5-5_13-53-38.png

    upload_2016-5-5_13-48-11.png
     
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