You'd need to post an example for specifics.
You have 3v+ from the button, so you need a 3v delay relay added to the bridge side triggered by 3v. The buttonn starts both item#1 and the delay relay for item#2. The input on the realy gets the 3v+. The load rating is how much powers the relay can safely switch (e.g. 12v 3a....3v 1a.....etc.
A module requiring very low amps(ma) at 3v to trigger it is ideal since you don't really know whats driving the 3v signal.
The load connection on the relay will get 3+ (or neg...visa/versa)
