distributor vs switchboard

distributor

noun
  • A device that distributes electric current, especially to the spark plugs in an internal combustion engine. 

  • One who or that which distributes. 

  • A machine for distributing type. 

  • An appliance, such as a roller, in a printing press, for distributing ink. 

switchboard

noun
  • A large piece of power-distribution equipment that directs electricity to multiple loads. 

  • The electronic panel that is used to direct telephone calls to the desired recipient. 

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