Current sensing module for a variable speed AC motor drive for use with a treadmill

摘要

A current sensing module for use with a variable speed AC motor control drive system for use with devices such as treadmills and including a module to sense the current of pulse width modulated signals provided to an AC motor wherein the current sensing module includes a fast sense circuit to sense excessive current conditions in the pulse width modulated signals and a slow sense circuit to sense average current values in excess of desired values over a predetermined period of time to protect the AC motor from damage caused by the increased frictional resistance to the rotation of the walk belt on the treadmill deck as the walk belt and treadmill deck wear out.