The old-style fire alarms (like in school where you pull the fire alarm and the bell goes off) were electrical systems. All modern fire alarm systems are electronic. The detection of smoke (fire) or break-in (burglar), the triggering of the alarm, the automatic call to the fire/police station, the keypad to enter the code to shut it off are all microprocessor-driven electronic systems (wireless in many cases).
Reflective umbrellas make more efficient use of light, but can lead to harsh shadows or hotspots. Shoot-through umbrellas will give a much more even light which I think if what you need.