Abstract: A Variable Frequency Drive (VFD) supplies power to rotate a motor, controlling both the speed and direction. The method normally used for this power conversion by the VFD results in energy losses and line harmonics. When the motor is driven by the VFD to be rotating at the same speed and direction as if the motor was straight across the incoming AC power, a transfer in power supply to the motor can be made using contactors to bypass the VFD. When in this bypass mode, the energy losses of the VFD are greatly reduced, and the line harmonics due to the VFD are greatly reduced. When it is subsequently recognized that the speed reference has deviated from being the same speed and direction as if the motor was straight across the incoming AC power, a transfer in power supply can be made from using contactors to once again drive the motor from the VFD.

Abstract: A Variable Frequency Drive (VFD) supplies power to rotate a motor, controlling both the speed and direction. The method normally used for this power conversion by the VFD results in energy losses and line harmonics. When the motor is driven by the VFD to be rotating at the same speed and direction as if the motor was straight across the incoming AC power, a transfer in power supply to the motor can be made using contactors to bypass the VFD. When in this bypass mode, the energy losses of the VFD are greatly reduced, and the line harmonics due to the VFD are greatly reduced. When it is subsequently recognized that the speed reference has deviated from being the same speed and direction as if the motor was straight across the incoming AC power, a transfer in power supply can be made from using contactors to once again drive the motor from the VFD.

Abstract: An adjustable carrying assembly for a wireless communication device, such as a radiotelephone. The carrying assembly is comprised of a device support member having a first spring coupled thereto for receiving the communication device and a clip mechanism coupled thereto for mounting the carrier assembly on a user's belt or other article of clothing. The clip mechanism comprises a clip support member, a pin, a clip, a second spring and a cap. One end of clip support member includes an opening with a plurality of grooves arranged in a circular array. The device support member is rotatably attached to the clip support member of the clip mechanism such that when the user rotates the device support member with respect to the clip mechanism, first spring moves from one of the plurality of grooves to another of the plurality of grooves and locks into position.