I'm working on a project in which I need to trigger a PLC with the start of an audio source. The PLC can only receive a 115V source as a trigger but the output jack of say an ipod is no where near that. What device can I use in order to provide a closed path of 115V to the input of the PLC when the audio source starts? Thanks..
have a look for audio (or voice) operated relay (or switch) e.g. AOR, VOX.
You can get sound/audio triggered relay kits and schematics all over the internet. The relay is used to trigger the PLC input by connecting the signalling voltage to it.