Abstract: Motor control apparatus comprised of a drive circuit for supplying drive current to a motor, an overload detector coupled to the motor for detecting the magnitude of the motor current to produce an output signal if that current exceeds a predetermined threshold level caused by motor overload, and a control circuit coupled to the drive circuit and responsive to the output signal for controlling the drive current supplied to the motor, thereby controlling motor operation.

Abstract: A device to control an electric well pump motor to pump continuously so long as there is liquid available to be pumped from the well. Whenever there is insufficient liquid to be pumped, the device causes shut-off of the electric pump motor. When liquid again becomes sufficiently available, the device causes pumping operations to resume. Liquid availability conditions are examined by the device at periodic intervals. The device comprises an adjustable variable-area-orifice restricted section in a liquid passage conduit, a pressure switch, a timer, an electric motor, and a motor control switch.