Definition
A combined electrical unit that first steps alternating current (AC) voltage up or down through a transformer, then converts that AC into direct current (DC) through a rectifier. In aircraft, transformer/rectifiers are commonly used to supply DC power to the aircraft's DC bus from the AC electrical system.
Plain English
A device that takes AC power, adjusts its voltage, and turns it into DC power so the aircraft's DC systems can use it.
Context Anchor
Seen in aircraft electrical system descriptions, maintenance manuals, and abnormal procedures for loss of electrical power.
Derivation
A compound name describing the two functions performed in sequence: the transformer changes the voltage level, and the rectifier converts AC to DC. 'Rectify' comes from the Latin 'rectus' meaning 'straight' -- the device 'straightens' the alternating waveform into one-direction flow.
Why Pilots Care
Failure of the unit can interrupt DC power to essential instruments and avionics, requiring immediate pilot action to maintain safe flight.
Analogy
It is like a travel power adapter that changes wall power into the kind your device needs, except in an aircraft it is built into the electrical system and supplies aircraft equipment.
Grounding Statement
The unit sits in the avionics compartment quietly converting generator output into the steady power the cockpit displays and radios require.
Intuition Check
Do not think of a transformer/rectifier as a battery. It does not store electrical power; it converts power from one form to another while a source is supplying it.
Example Sentence 1
After the generator came online, the transformer/rectifier supplied DC power to the main DC bus.
Example Sentence 2
After an alternator failure the pilot monitors the transformer/rectifier output to confirm backup battery charging continues.