rectifier vs restorer

rectifier

noun
  • Something that rectifies. 

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

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

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

restorer

noun
  • One who restores. 

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