Definition
A two-transistor circuit in which the emitter of the first transistor feeds directly into the base of the second, so the two act together as a single transistor with very high current gain. The result is a device that can be switched on or controlled by an extremely small input current while handling a much larger output current.
Plain English
A pair of transistors wired so they work as one super-sensitive transistor. A tiny input signal can control a much bigger output, which is useful when the available signal is weak.
Context Anchor
Seen in aircraft electronics, electrical system troubleshooting, voltage regulator discussions, and component-level maintenance of control circuits.
Derivation
Named after Sidney Darlington, a Bell Labs engineer who patented this transistor pairing in 1953. The name comes from the inventor, not from how the circuit works.
Why Pilots Care
A pilot normally does not operate a Darlington amplifier directly, but understanding the term helps when reading about aircraft electrical equipment or maintenance reports where small control signals operate larger electrical devices.
Analogy
Think of it like two people passing along a push: the first person responds to a very light touch, then passes a stronger push to the second person, who can move something heavier. The circuit works in a similar way with electrical current.
Intuition Check
Do not read “amplifier” here as only an audio device that makes sound louder. In this context, it means an electronic circuit that makes a small electrical signal able to control a larger current.
Example Sentence 1
The voltage regulator used a Darlington amplifier so that a small signal from the sensing circuit could control the much larger field current of the alternator.
Example Sentence 2
When checking the instrument lighting dimmer, the technician verified that the Darlington amplifier stage was delivering the expected current gain.