Abstract: A water treatment device, comprising: a controller operably connected to a tank containing a water softening resin; a sensor in communication with the controller and configured to provide date for determining a treatment capacity of the water softening resin and for determining a quantity of water treated by the water softening resin; and a valve configured to pass water to be treated through the water softening resin; wherein the controller is configured to monitor a remaining treatment capacity of the water softening resin by subtracting the quantity of water treated by the water softening resin from the treatment capacity of the water softening resin; and wherein the controller is configured to record the remaining treatment capacity, as a negative value, when the quantity of water treated by the water softening resin exceeds the treatment capacity of the water softening resin.

Abstract: A method is provided for reducing common mode voltages in a system that includes an inverter connected to a motor by a long cable by controlling switches of the inverter to generate voltage vectors that emulate a three-phase sinusoidal waveform by switching between adjacent active vectors and active vectors that are separated by 180 degrees, determining whether a phase angle of the vectors is increasing or decreasing, determining a decision angle within the sector which is a function of a duty cycle offset and a modulation index; and applying duty cycle manipulation rules, including: responding to an increasing phase angle that is less than the decision angle by setting a duty cycle of the adjacent active vectors to a duty cycle high value; and responding to an increasing phase angle that is greater than 60 degrees minus the decision angle by setting the duty cycle to a low value.

Abstract: An electric motor has a control circuit that enables an operational speed of the electric motor to be selected with reference to multiple ranges of speeds and the input voltage to the motor. Switching between speed ranges occurs in response to activation of a switch or in response to expiration of a time period set by a selector switch.

Abstract: An electric motor has a control circuit that enables an operational speed of the electric motor to be selected with reference to multiple ranges of speeds and the input voltage to the motor. Switching between speed ranges occurs in response to activation of a switch or in response to expiration of a time period set by a selector switch.