Re: prony brake

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Ed Phillips <evp@xxxxxxxxxxx>

   Prony brakes are not for the unwary user!  I had an interesting 
experience once as I watched somebody using a prony brake; thing 
seized up and stuff was flying everywhere.  Motor under test was a 5 
hp single phase jobby (mighty large for single phase) and there was a 
lot of energy stored in the rotor.  Use of a generator on bearings 
works fine and is a lot safer.  You vary the load on the generator to 
vary the shaft torque, or use a fixed load and vary the field 
current. The torque is measured with a spring scale or balance on the 
rotatable case.

Ed