drag cup meaning

• [Electronics]
  A cup of nonmagnetic metal (usually copper or aluminum) that, when rotated in a magnetic field, acquires a voltage proportional to the speed of rotation. The device is often used as a brake.
  

• drag-cup motor:    [Electronics]A ser ...
• a drag:    [American slang]Sl ...
• be a drag:    [American idiom]to ...

Examples

1. :: : : Sounds a bit like drag cup but thats a rotating magnet inside an aluminium cup ( use as a speedometer in the past )-- Light current 17 : 13, 14 September 2006 ( UTC)