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.
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.