1712 results about "Electric coupling" patented technology

Certain embodiments provide a system configured to heat a subsurface formation. The system includes an electrical power supply. A heater section includes one or more electrical conductors electrically coupled to the electrical power supply. At least one of the electrical conductors includes ferromagnetic material. The heater section provides a first heat output when time-varying electrical current is applied to the heater section below a selected temperature, and a second heat output approximately at and above the selected temperature during use. The second heat output is reduced compared to the first heat output. The system is configured to allow heat to transfer from the heater section to a part of the formation. The electrical power supply is configured to provide a relatively constant amount of time-varying electrical current that remains within about 15% of a selected constant current value when a load of the electrical conductors changes.

Methods and apparatus are disclosed for minimizing or eliminating an undesired axial electric current induced along a subsurface borehole in the process of subsurface measurements with transmitter and / or receiver antennas which are substantially time varying magnetic dipoles with their dipole moments aligned at an angle to the axis of the borehole. Some antennas are disposed within the borehole on instruments having a non-conductive support member. One instrument includes a conductive all-metal body with an antenna adapted for induction frequencies. Antenna shields adapted for controlled current flow are also provided with an all-metal instrument. Methods include providing an alternate path for the current along the instrument body. Another method includes emitting a controlled current to counter the undesired current. Another method corrects for the effect of the current using a superposition technique. An embodiment of the instrument includes an antenna disposed between a pair of electrically coupled electrodes. The antenna is disposed on the instrument such that it comprises a tilted or transverse magnetic dipole. Another embodiment of the instrument includes a non-conductive housing with a conductive segment disposed thereon. An antenna is disposed on the instrument about the conductive segment. Another embodiment includes an antenna disposed between two pairs of electrodes with means to measure a voltage at the electrodes when electromagnetic energy is transmitted within the borehole. Yet another instrument includes an antenna disposed between a first pair of electrodes and means to measure a voltage at the electrodes when electromagnetic energy is transmitted within the borehole. This embodiment also includes means to energize a second electrode pair in response to the voltage measured at the first electrode pair.

A tandem-connected rotatable receptacle unit is provided. The unit includes a primary receptacle having a housing, an electric plug with an electric cord disposed at the front end of the housing, and a first slot set formed at the rear side of the primary receptacle for the output of power. The unit further includes at least one tandem connection receptacle having a blade set at the front side of the housing, the blade set being fixed at a round seat. The blades of the blade set are each coupled to a conducting wire electrically coupled to a conducting piece of a first slot set at the rear end of the tandem connection receptacles. The tandem connection receptacle further includes a second slot set at a side wall and a projecting rib provided at the circumference of the round seat, whereby the round seat can be rotated about the round seat for adjusting the direction of a second slot set at the side wall of the housing.

An improved rack-mounted server comprises, in one embodiment, a slidable electronics tray having a top cover secured to the rack, to facilitate access to the tray when it is withdrawn from the rack. The tray also includes a camming mechanism to facilitate insertion of the tray into and its extraction from cable connectors or plugs affixed to the rack. The tray includes, in one embodiment, a movement detection mechanism to power it up or down when tray insertion or removal, respectively, is initiated. In addition, the rack includes an improved cable management system that can accommodate different cables and cable plugs. As a tray is inserted into or removed from the rack, corresponding connectors on the tray are electrically coupled to or uncoupled from cable plugs affixed to the rack, eliminating any need to remove cables from the tray or reinstall them.