Definition
A short, sharply rising electrical pulse used to start, switch, or time the operation of an electronic circuit. The pulse itself carries no information beyond its timing; its job is to tell the circuit when to act.
Plain English
A quick electrical 'kick' that tells a circuit to do something at a specific moment.
Context Anchor
Seen in aircraft maintenance and electrical system descriptions, especially where an electronic unit must start an action at an exact moment.
Derivation
From 'trigger,' meaning the part of a gun that starts the firing action when pulled. The electrical pulse 'pulls the trigger' on the circuit, starting whatever action it is designed to do.
Why Pilots Care
Proper trigger-pulse timing keeps the engine firing smoothly; an incorrect or missing pulse can produce misfires, roughness, or hard starting.
Intuition Check
Do not picture a physical trigger being pulled. In this use, the “trigger” is a short electrical signal that starts an action inside equipment.
Example Sentence 1
The transponder sends out a reply only after receiving a trigger pulse from the ground interrogator.
Example Sentence 2
The crankshaft position sensor sends a trigger pulse to the electronic ignition module to begin the combustion sequence.