dongle vs rectifier

dongle

noun
  • Any small device that plugs into an electronic device, typically a computer, and alters its functionality. Common examples include wireless modems, digital media players, software copy protect devices, and adapters. 

  • A hardware device utilized by a specific application for purposes of copy protection. 

rectifier

noun
  • A device that converts alternating current into direct current; often a diode. 

  • The activation function f(x)= max (0,x), where x is the input to a neuron. 

  • An instrument used for determining and rectifying the variations of the compass on board ship. 

  • Something that rectifies. 

How often have the words dongle and rectifier occurred in a corpus of books? (source: Google Ngram Viewer )