adjustable-speed drive alternating current carl schenck chart recorder chassis computer coupling crankshaft data acquisition de prony brake direct current drag racing dynameter dynamometer car eaton corporation electric motor electromagnetic brake engine test stand flywheel foot-pound force gaspard de prony graph of a function hand strength heat engine horsepower hysteresis internal combustion engine load cell motor newton metre on-board diagnostics oxygen sensor plotter revolutions per minute rotational speed tachometer torque torque sensor transducer trunnion variable-frequency drive water brake watt weighing scale wheel william froude