Variable-speed motor drive controller for a pump-motor assembly

摘要

A liquid pump system for providing liquid to a tank includes a variable-speed motor drive and a control circuit coupling the variable-speed motor drive to a power source. The control circuit has a switch that may be disposed in a state according to the amount of liquid in the tank. The control circuit provides for supplying power to the variable-speed motor drive from the power source regardless of the state of the switch. The control circuit may include a transmitter that generates a high frequency signal representative of the state of the switch. In that embodiment, a detector coupled to the variable-speed motor drive receives the high frequency signal to control operation of the liquid pump system.