liquid barretter

1 definition found

liquid barretter - Collaborative International Dictionary of English v.0.48 :

  barretter \bar"ret*ter\, n. [OF. bareter to exchange. Cf.
     Barter.]
     1. (Electronics) a resistor inserted into a circuit to
        compensate for changes (such as those arising from
        temperature fluctuations); a thermal cymoscope.
  
     Syn: ballast resistor.
          [Webster 1913 Suppl. + WordNet 1.5]
  
     Note: The original form consisted of an extremely fine
           platinum wire loop attached to terminals and inclosed
           in a small glass or silver bulb. It operates by
           increased resistance when subjected to the influence of
           an electric current. In a later variety, called the
  
     liquid barretter, wire is replace by a column of liquid in
        a very fine capillary tube. A recent version has a
        resistor composed of an iron wire in a glass bulb
        containing hydrogen, with the temperature variation of
        resistance such that the current passing through it
        remains constant over a wide range of applied voltages.
        [Webster 1913 Suppl. + PJC]