The device that controls the fan speed is called a variable speed drive. Variable frequency drives are also used on pumps and cooling towers to match the demand of the space with the proper energy ...

This article explains how an AC drive accomplishes this. Simply put, an AC drive, also referred to as a variable frequency drive (VFD), is a power supply control and conditioning device for AC motors ...

WSB photo, Cove Park entrance) Three weeks ago, warning signs like that one were up at and near Cove Park south of the ...