Abstract: A circuit, for monitoring and controlling parameters of an electrosurgical unit, ESU, relative to load and the RF energy, has a load responsive output sensing circuit that measures the ESU load. A signal modifier, attached to the sensing circuit enhances the signals measured and transmits them to a buffer. An analog to digital converter, A/D, digitize the signals and samples wave pulse train at about eight million samples per second. A data memory stores the digitized signals. A RF drive clock connects to the ESU output; a sample clock uses phase shifting to interrogate the input signals to a processor, DSP, at a greater sampling rate of frequency than without. The DSP receives the stored signals from the data memory and processes them while monitoring and calculating ESU parameters measured, i.e.

Abstract: A pump for producing a substantially smooth and continuous outflow of liquid at relatively high pressure has two piston assemblies flow connected in series. The first piston assembly includes a pressure piston having a long suction stroke and a relatively short and abrupt expulsion stroke. A valve at the inlet of the pressurization piston allows flow to enter (but not exit), and a valve at the outlet of the pressurization piston allows flow to exit (but not enter). The second piston assembly includes a damper piston which functions as a mechanically driven damper to smooth the outflow from the pressure piston. This smoothing is accomplished by storing of the liquid displaced by the expulsion stroke of the pressure piston and then delivering the stored pressurized liquid to the pump outlet during the suction stroke of the pressure piston.

Abstract: A lubricating system which is completely self contained within the vacuum environment of an electric direct drive system for an ultracentrifuge rotor. The lubricating system also functions as a cooling means for an electric motor within the drive system by the use of a unique cooling feed tube in the central portion of the drive system. An orifice in the top of the cooling feed tube will control the head of the lubricating medium within the system. Specific design of the fit between the direct drive assembly and the drive housing in conjunction with the head on the lubricating medium will regulate the drip rate of the lubricating medium to the bearings. The use of the unique lubrication and cooling system maintains the close tolerances of the various elements such as the high speed bearings of the drive system because the temperature of the overall drive system is controlled.

Abstract: A high vacuum turbomolecular pump is described incorporating a drive system which significantly reduces the amount of heat build-up therein. The pump includes an outer casing having an upper open end adapted to be communicated hermetically with an isolated environment to be pumped, and an exhaust opening at its lower end. A plurality of vertically spaced stator blade wheels are positioned within the casing intermediate the inlet and exhaust openings, and a rotor is mounted within the casing on a spindle for rotation therewith on a generally vertical axis. The rotor is provided with a plurality of axially spaced rotor blade wheels interleaved with the stator blade wheels. An electrical induction motor is incorporated into the pump with its rotor output shaft being the spindle so as to rotate such spindle and, hence, the pump rotor for high vacuum pumping.

Abstract: A high vacuum turbomolecular pump is described having a lubrication system which assures steady, continuous lubrication of the rotor bearings. The pump includes an outer casing having an upper open end adapted to be communicated hermetically with an isolated environment to be pumped, and an exhaust opening at its lower end. A plurality of vertically spaced stator blade wheels are positioned within the casing intermediate the inlet and exhaust openings, and a rotor is mounted within the casing on a spindle for rotation therewith on a generally vertical axis. The rotor is provided with a plurality of axially spaced rotor blade wheels interleaved with the stator blade wheels. An electrical induction motor is incorporated within the pump for rotating the spindle and, hence, the pump rotor, for high vacuum pumping.