Reference number
  • LAN/6/209
Alternative reference number
  • 1925-232772
Level
  • Item
Date
  • 04 Jan 1926
Description
  • Gramme or ring type of armature, which can withstand speeds of 18000 to 20000 feet per second (f.p.s.) compared with the usual 3000 or 4000 f.p.s. Refers also to the bearings of the armature, and links to the commutator.