Definition
An electronic device that takes a small input signal and produces a larger output signal of the same form, using power drawn from a separate source. In aircraft systems, amplifiers are used to strengthen weak signals from sensors, antennas, or transducers so they can drive instruments, radios, or control circuits.
Plain English
A device that makes a weak electrical signal stronger so it can do useful work, such as driving a speaker, gauge, or radio.
Context Anchor
Seen in aircraft electrical, radio, audio, sensor, and control-system maintenance.
Derivation
From Latin amplificare, 'to enlarge' (amplus = large + facere = to make). The word literally means 'something that makes larger,' which matches what the device does to an electrical signal.
Why Pilots Care
Weak signals from microphones, antennas, or sensors must be strengthened for clear communication and accurate instrument readings.
Intuition Check
Do not assume an amplifier only means something that makes sound louder. In aircraft systems, an amplifier can strengthen many kinds of electrical signals, not just audio.
Example Sentence 1
The technician traced the weak audio in the headset back to a failed amplifier in the intercom system.
Example Sentence 2
The navigation signal was too weak until the amplifier boosted it for the cockpit display.