noun
converter; transducer
A device or component that converts one form of energy, signal, or data into another. Common in engineering and electronics.
この変換器はアナログ信号をデジタル信号に変える。
This converter changes an analog signal into a digital signal.
電力変換器の効率が重要だ。
The efficiency of the power converter is important.
変換 is the general noun for 'conversion' or 'transformation'; 変換器 specifically refers to the device that performs the conversion.
Compound of 変換 (conversion) + 器 (device, instrument).