How would you go about to wire this?

[pushrod]

I think what you are after is fairly easy to achieve but it will be via electronic control using logic gates etc on a circuit board that will be doing the switching, so i suspect you really need a different forum unless you are lucky to get an electronics expert on here.

 

[nickblake]

yep you can do that , use a timer circuit with a switch operating a set of relays so to keep the mike signal seperate so ,you switch a switch on the mike comes on and switches a relay which operates a timer for approx 15 mins when the timer ends the socket goes off but the mike remains on ,switch mike on and off again and the timer will stay on for 15 mins see what i mean will that help

 

[Rappid]

Google '555 timer' based on the LM555 chip, very easy to build and quite cheap, only requiring a few components, connect to to a relay for switching, job done.

 

[nickblake]

go to ceebek kits they do a timer with relay for £12.00 complete ready buit kit 0 to 45 mins ive used them very good