Abstract: A compressor for a heat transfer circuit includes a variable frequency drive (VFD), an electric motor that rotates a driveshaft, bearing(s) for supporting the driveshaft, a backup gas supply, and a power supply. During a utility power interruption, the backup gas supply operates utilizing DC electrical power generated by a back electromotive force of the electric motor. A method of operating an electric power supply system for a compressor includes operating in a utility power mode and operating in a backup power mode during a utility power interruption. In the utility power mode, AC electrical power is supplied from the VFD to the motor. In the backup power mode, DC electrical power generated in the VFD by a back electromotive force of the motor it used to operate a backup gas supply to supply compressed working fluid to gas bearing(s) of the compressor.

Abstract: The present invention provides a system and method for efficiently transferring files using file differentiation. In architecture, the system includes a client device with a device file, a server device containing an original file and a revision file of the original file, and a delta file that identifies only the changes between the original file and the revision file. The present invention can also be viewed as a method for efficiently transferring files using file differentiation. The method operates by (1) providing an original file; (2) creating a revision file of the original file; and (3) generating a delta file that identifies only the changes between the original file and the revision file.

Abstract: The present invention provides a system and method for efficiently transferring files using file differentiation. In architecture, the system includes a client device with a device file, a server device containing an original file and a revision file of the original file, and a delta file that identifies only the changes between the original file and the revision file. The present invention can also be viewed as a method for efficiently transferring files using file differentiation. The method operates by (1) providing an original file; (2) creating a revision file of the original file; and (3) generating a delta file that identifies only the changes between the original file and the revision file.