Before the Declaration of Independence. Even after the initial battles in the Revolutionary War broke out, few colonists desired complete independence from Great Britain, and those who didâlike John Adamsâ were considered radical.
A variable-frequency drive is a device used in a drive system consisting of the following three main sub-systems: AC motor, main drive controller assembly, and drive/operator interface.ariable-frequency drives are also categorized by the following load torque and power characteristics: 1  Variable torque, such as in centrifugal fan, pump, and blower applications. 2  Constant torque, such as in conveyor and positive-displacement pump applications.
A variable speed drive takes the electric power from the feeding. network at the standard network frequency. In the rst stage the. alternating current (AC) is recti ed to direct current (DC) in a rectier. unit. This rectier can be either a diode bridge or a thyristor bridge, depending on the drive system.