摘要:
Public alert and advisory systems for the communication of emergency and/or other information from one or more central locations to a plurality of remote locations, such as, by way of example, information regarding a nuclear accident and evacuation procedures. This system utilizes conventional programming stations such as AM, FM or TV stations, central transmitting equipment, with the emergency information being modulated by a second modulation technique differing from the first modulation technique for the ordinary programming so that conventional manually operated programming receivers will not be responsive to the emergency information. The receivers of the system however, are responsive to the transmitted emergency information, so as to sound a warning alarm, display codes relating to evacuation or other information and/or receive and present audio information depending upon the specific configuration of the system. Normally the remote receivers are given recognition codes so that the receiver may be given different emergency information, either on an individual or on a group to group basis. Fault detection is provided by configuring the remote receivers to automatically provide a fault indication if not periodically reset by the communications link. A unique telephone link, also disclosed, can be used for reliability testing or for ordinary data communication. Various embodiments and features are disclosed.
摘要:
In one general aspect, a system to control and monitor an electrical system includes a switchgear housing unit connected to the electrical system that includes a switchgear mechanism for controlling a connection within the electrical system and electronic controls for monitoring and controlling the switchgear mechanism, where the electronic controls are embedded within the switchgear housing unit to form a single, self-contained unit.
摘要:
A current interrupter assembly includes an insulating structure, a current interrupter embedded in the structure, a conductor element embedded in the structure, a current interchange embedded in the structure and connected to create a current path between the current interrupter and the conductor element, and a semiconductive layer covering at least a portion of the conductor element so as to reduce voltage discharge between the conductor element and the structure.
摘要:
A mechanical reinforcement for an electrical apparatus has at least one electrical element with an outer surface and a reinforcing structure attached to the outer surface. The electrical element may be a monolithic MOV disk or a bonded MOV disk stack. The monolithic element may, for example, have a rating greater than 6 kV. The reinforcing structure may be pre-impregnated fiber matrix that may be, for example, pre-impregnated with resin. The mechanical reinforcement provides improved high current durability to the electrical apparatus.
摘要:
An improved vacuum interrupter is disclosed. The vacuum interrupter includes a ring-shaped structure placed between a contact support structure and an electrical contact associated with the contact support structure. A resistivity of the ring-shaped structure is higher than that of the contact support structure, so that current traversing the ring-shaped structure on its way from the contact support structure to the electrical contact is evenly distributed. The ring-shaped structure may be fit into an end portion of the contact support structure, the end portion having an diameter less than an outer diameter of the support structure, but greater than an inner diameter of the support structure. Alternatively, the end portion may be used without the ring-shaped portion, in which case the electrical contact may be shaped to fit into the end portion.
摘要:
A closed loop feedback system controls electrical switchgear that moves at least one contact relative to another contact to switch power on and off in an AC electrical circuit. The control system includes a position feedback device that is operatively coupled to at least one of the two contacts to produce contact position information. A processor receives and analyzes the contact position information to control contact motion to provide AC waveform synchronized switching. The electrical switchgear may be a capacitor switch that includes a bi-stable over-toggle latching device. The latching device maintains the contacts in one of an open stable position in which electrical current does not flow through the contacts or a closed stable position in which electrical current flows through the contacts.
摘要:
A surge arrester module having an array of MOV's and other components includes an insulative coating (16) for applying an axially compressive force to the stacked array. The component stack (20), while held in an axially compressed condition, receives the insulative casing that includes thermosetting resin that, when cured, has a coefficient of thermal expansion that is greater than that of the components of the stack. The coated stack is then cured at a temperature that exceeds the maximum expected temperature that will be experienced by the arrester components. Upon cooling, the components of the array are held in compression and adequate electrical contact with each other is maintained by the casing. Fiberglass strands (24, 28) are included in the casing for reinforcement and cantilever strength. A method of manufacturing the module is also disclosed.
摘要:
A material finishing line including a essentially linear array of work stations is disclosed. A stationary support beam extends over the work stations and substatially encloses a transmission, and supports at least one crane body and a drive means to selectively propel the crane body along the support beam. The crane body is an assembly of components arranged to raise workpieces from the work stations towards the support beam. A `U` shaped cart supports lift means to provide power to raise a lift arm and supports the lift arm and a lift arm guide. The vertical extensions of the support beam and of the cart are reduced and nearly overlap, and the vertical extension of the lift arm may be lifted into substantially overlapping relationship with the vertical extension of the cart. The ability to substantially tuck the lift arm onto the cart and a reduced vertical extension of the cart and support beam provide a material finishing line which only requires minimal headroom while reducing the dead space through which a workpiece cannot be lifted. To the same end, transmission means to propel the cart and conductors to supply the mobile lift means are substantially contained within the support beam and cart. Additionally the support beam is an assembly of support modules, which in turn are assemblies of easily fabricated standard shapes. Similarly the crane body components are assembled from easily fabricated standard shapes.
摘要:
A voltage regulator is described adapted for use controlling the output of an AC generator. A voltage control field-winding excitation control circuit supplies direct current to the generator field in response to a driver. The driver, in turn, is operated in response to a switching regulator. A frequency sensing means generates a voltage proportional to the frequency of the generator. This frequency sensitive voltage is combined with a reference voltage to drive an asynchronous switching regulator. The switching regulator produces a train of output voltage control signals to operate the driver. Preferably power MOSFETs are used to control the flow of current to the generator field. Loss of voltage and high current protection features are included.