Current Sensing Apparatus

摘要

A current sensing device (50) having a plurality of discrete, repeatable, user-selectable setpoint values. Current sensing circuitry (32) of the device includes a multi-position switch (34) operative to alternatively connect discrete impedances (e.g. resistors R1, R2, R3, or R4) into the circuit in order to change the setpoint value. A calibration scale (42) associated with a user-input knob (44) of the multi-position switch may be marked with values of horsepower which correspond to the size of a motor that has a motor nameplate rating equivalent to the sensed current setpoint associated with each switch position. A second switch (52) may be provided to allow the user to select an offset for the setpoint value.