I don't actually know, I'm not an electrician although I do have qualifications as a sound engineer. You should have sufficient power - 12V 2.8A should be more than enough. If you can understand people better as power fades that would seem to back that up. Logically you are looking at some kind of interference. Unshielded cables carrying audio signals are vulnerable to all kinds of electrical or radio interference from nearby equipment. You might simply have too many cheap wires too close together - but I suspect your soldered joints may be more of an issue. Make very sure there is nothing touching anything that could possibly be conducting electricity between different wires...
Comment has been collapsed.
385 Comments - Last post 4 minutes ago by sevenweasel
1,736 Comments - Last post 1 hour ago by MBaer
213 Comments - Last post 2 hours ago by looseangel
17,148 Comments - Last post 3 hours ago by pivotalHarry
67 Comments - Last post 3 hours ago by JonathanDoe
15 Comments - Last post 4 hours ago by Fluffster
4 Comments - Last post 4 hours ago by gameboy9725
1,240 Comments - Last post 22 minutes ago by Tucs
153 Comments - Last post 22 minutes ago by Ad4m
113 Comments - Last post 28 minutes ago by StarPONY
280 Comments - Last post 36 minutes ago by Askelladd
161 Comments - Last post 54 minutes ago by Myrsan
30,539 Comments - Last post 1 hour ago by Yamaraus
152 Comments - Last post 1 hour ago by forseeker
Just installed new domophone in school (part of my job)
There is 2 parts of domophone.
One is only microphone/speaker and a button to call. only 2 wires.
Second one is phone. 12V.
Only phone have power supply.
Firs part of domophone takes power together with audio signal through 2 wires.
Cable between those parts is long. Atleast 20 meters. UTP. Unshielded.
with atleast 5 joints. some of them are soldered, others are not.
And through same cable I connected controller (ethernet) and 12V minus through 2 cables. If I connect them then door opens.
TL:DR
8 wires. 4 for ethernet use, 2 for 12V minus of conntroller. 2 for audio signal and power supply to first part of domophone.
The problem is I have loud noise when trying to communicate through it.
At first I used 12V Volt LED DC power supply 2,8A. But friend of mine said that it doesn't fit for audio devices.
If i unplug power supply from outlet, noise dissapears and for few seconds, while power supply still have some power left, I can clearly understand what someone speaking at other side of domophone.
I tried to changing power supply to 12V 1A adapter taken from ethernetswitch.
Sound and noise was even bigger.
Friend of mine suggested to add 1000mF capacitor. But that didn't helped.
Any suggestions?
Sorry for bad english :D
Comment has been collapsed.