Definition
A remote-indicating electrical system that uses a permanent magnet rotor in a transmitter and a matching magnet rotor in an indicator, both wrapped in toroidal coils energized by AC. The transmitter rotor is moved by the quantity being measured (such as fuel level, position, or pressure), and the indicator rotor follows it precisely, displaying the measurement on a dial in the cockpit.
Plain English
An electrical setup that lets a gauge in the cockpit show what is happening at a sensor somewhere else on the aircraft. A small magnet at the sensor turns, and a matching magnet inside the gauge turns the same way, so the cockpit needle mirrors what the sensor is doing.
Context Anchor
Seen in aircraft instrument and maintenance discussions where an engine or aircraft condition must be displayed on a gauge away from the actual sensing unit.
Derivation
The name combines 'magnet' with 'syn' (from synchronous), reflecting how two magnets stay in step with each other.
Why Pilots Care
It provides reliable cockpit display of engine and fuel data without mechanical linkages that can wear or break.
Intuition Check
Do not think of a Magnesyn system as a cable or rod that physically pulls a pointer. It is an electrical system that makes a remote indicator follow a sensed change by magnetic action.
Example Sentence 1
The fuel quantity gauges on this aircraft use a Magnesyn system, so the readings depend on AC power being available.
Example Sentence 2
During the inspection the mechanic verified that the Magnesyn system was delivering accurate oil temperature indications to the cockpit.