There are a lot of processes that require continuous, smooth running, rotary motion. But sometimes two different speeds are necessary. Inverters or servo gearheads can’t always deal with the differences. In a lot of applications, variable speed can be accomplished with an inverter. By varying the hertz a motor can operate at a relatively wide speed range. However, when running above 60 Hz there is usually a drop off in output torque. And when the hertz drop below 20, in many instances additional cooling is necessary because the fan isn’t turning fast enough. And [...]