Definition
An electrical device that transfers alternating current (AC) electrical energy from one circuit to another through electromagnetic induction, typically changing the voltage up (step-up) or down (step-down) in the process. It consists of two or more coils of wire wound around a common iron core, with the ratio of turns between the primary and secondary coils determining the change in voltage.
Plain English
A device that takes AC electricity at one voltage and changes it to a different voltage, either higher or lower, so it can be used by equipment that needs that specific voltage.
Context Anchor
Seen in aircraft electrical-system maintenance, especially where one part of the system needs a different voltage than another part.
Derivation
From Latin 'transformare' — 'trans' (across) and 'formare' (to shape). The device 'transforms' electricity by reshaping its voltage as it passes from one coil to another.
Why Pilots Care
Aircraft rely on transformers to deliver correct voltages to radios, instruments, lights, and other systems; a faulty unit can cause equipment failure or electrical fires.
Analogy
A transformer is like a pressure changer in a water system: the flow is still there, but the pressure is adjusted so the next part can use it safely.
Intuition Check
A transformer is not just anything that changes something. In aircraft electrical systems, it means a specific device that changes electrical voltage by magnetic action.
Example Sentence 1
The aircraft's lighting transformer steps the 115-volt AC supply down to the lower voltage required by the instrument panel lights.
Example Sentence 2
During preflight, the pilot noted that the avionics were receiving proper voltage after the transformer was checked.