Abstract: A system includes a controller for a DC to AC inverter including a processor configured to execute instructions to perform operations including: generating a first pulse for a first phase of a center-aligned PWM signal to alternately activate a first phase switch of a first switch group of the inverter for a first duration and a first phase switch of a second switch group of the inverter for a second duration within a period of the PWM signal; and generating a second pulse for a second phase of the PWM signal to alternately activate a second phase switch of the first switch group of the inverter for a third duration and a second phase switch of the second switch group of the inverter for a fourth duration within the period of the PWM signal, wherein the second duration is different from the third duration during a stall condition.

Abstract: An electric motor control circuit includes an electric energy storage device electrically connected via DC power buses to an inverter circuit that connects via an alternating current circuit to an electric machine. A capacitive shunt circuit connects between the power buses. Current flow through the capacitive shunt circuit to the chassis ground is monitored. A fault is identified when the current flow through the capacitive shunt circuit to the chassis ground exceeds a threshold.

Abstract: An electric motor control circuit includes an electric energy storage device electrically connected via DC power buses to an inverter circuit that connects via an alternating current circuit to an electric machine. A capacitive shunt circuit connects between the power buses. Current flow through the capacitive shunt circuit to the chassis ground is monitored. A fault is identified when the current flow through the capacitive shunt circuit to the chassis ground exceeds a threshold.

Abstract: A floor sanding vacuum is designed to be used in conjunction with floor sanding machines to provide a near dust free process for sanding floors. A displacement blower is driven by a gasoline or electric motor which creates a high vacuum that draws air through the sanding machine via a flexible hose connected to a cyclone separator where the sanding debris drops into an integral hopper. After the cyclone, the air is drawn through an air filter to the blower where the cleaned air is discharged through either an optional integral silencer built into the base of the vacuum or a commercially available silencer for noise reduction.