I was debating the characteristics of a DC Shunt Motor with come coworkers and would just like some clarification. A DC Shunt motor can be thought of as a "constant-speed" motor, right? This means that as the torqued load on the motor increases, a DC drive will increase the armature current required to drive the motor at the same speed. But as the load changes, so does the output (HP) of the motor, even if the DC drive is inputting the maximum power (Watts). This is where an efficiency map of the motor would be a useful item. This came about because we were trying to spec out a gearbox and I wasn't sure that the contracted engineer knew the workings of a DC motor. Am I correct in what I have said?