Creating a "One Shot" laser trigger.

[Bionic-Badger]

I'm with Hemlock Mike on this one, use a MOSFET, if only for the protection of your diode, and then get a solenoid or something. Any relay you use that has any kind of audible and useful "click" will 1) be large, 2) use quite a bit of voltage and energy for the coil, 3) may even cause a current spike that you don't want. A solenoid or speaker can do a much better job, and even make the "trigger" shake like it really did pulse a huge load of current.

Anyway you'll want to put in a nice big charge circuit right? So that you can hear the capacitor/inductor charging up for the big pulse for the solenoid or something. That'll give a really nice effect.