Abstract: A frequency synthesizer loop includes a first voltage controlled oscillator and a first divider circuit for dividing a frequency of an output signal generated by the first voltage controlled oscillator by a factor of N. The synthesizer loop further includes a phase/frequency detector circuit, a loop filter circuit, a summing circuit, a feedforward amplifier, a second voltage controlled oscillator, and a second divider circuit, wherein the second divider circuit divides a frequency of a second output signal generated by the second voltage controlled oscillator by a factor of M. The synthesizer loop also includes a microprocessor for varying the value M in response to a voltage input, such that the microprocessor varies the value of M to keep the first voltage in the middle of a range of the second voltage controlled oscillator.

Abstract: A system for preprocessing computer programs before downloading them into terminals includes a packager which processes certain information contained in compiled but unlinked programs. The packager partially resolves undefined symbols and relocations based on knowledge of a dispatch table in the destination terminal and other information known prior to the downloading process. Additionally, the packager determines the sizes of separate code, data, dispatch table and temporary symbol areas, incorporates this size information into a header, and transmits a data stream including the header and the aforementioned areas, including partially resolved symbols, to one or more terminals such as home communication terminals (HCTs) in a cable television network. Each receiving terminal extracts the size information and allocates only as much memory as is needed to store each of the separate areas, thus avoiding the need for a temporary holding buffer.

Abstract: A system and method are provided for selecting groups of one or more cable television subscribers remotely from a billing computer using data fields in either the billing computer database or a system control computer database. A selection criteria language may be used for selecting subscribers based on data fields in the system control database. Once a group of cable subscribers has been selected, an on-screen message may be remotely created and transmitted to the selected subscribers using cable transmission apparatus. The method provides a way of correlating subscriber information in a comprehensive subscriber database (such as may exist on a billing computer) with other subscriber information in a more limited database stored on a system control computer to allow on-screen messages to be targeted at subscribers selected on the basis of criteria from either database.

Abstract: A communication system for coupling telephony or other digital networks to a broadband network such as a CATV network. The system transmits a multiplex of telephony signals in the forward band of the broadband network, with individual signals directed to an addressed subscriber. Telephony signals returning from subscribers are modulated onto the reverse band of the broadband network in a frequency division multiplex (FDM). The modulated telephony signals are received at a telephony network interface coupled to the broadband network. A selected plurality of modulated telephony signals are frequency shifted to baseband. The baseband-shifted telephony signals are sampled to generate a plurality of time division multiple access telephony signal samples. A plurality of time division multiple access telephony signal samples are channelized into a serial data stream with a channelizer.

Abstract: A broadband communications system for coupling telephony or other digital networks to a CATV network. The system transmits a multiplex of telephony signals in the forward band of the CATV network. The forward telephony channels are demodulated and demultiplexed by a plurality of subscriber terminals into the individual telephony signals directed to an addressed subscriber. Signals returning from subscribers are digitized into standard telephony signals onto the reverse band of the CATV network, and demodulated and multiplexed into a standard telephony signal that is interfaced to the telephony network. A multiplicity of subscribers are initially assigned to a selected reverse band channel. If more than one subscriber contends for use of the reverse channel by transmitting in the channel, signals from the contending subscribers interfere and prevent any subscriber's identity from being decoded and acknowledged. The contending subscribers wait for a random wait time and re-attempt to transmit.

Abstract: A low force, multiple switch, multidirectional switch assembly for electronic games handsets or remote controls. The assembly comprises a housing having an opening, a first support and a second support having a opening. At least two spaced apart switches are provided, each comprising two spaced apart stationary contacts on the first support and a correspondingly aligned moveable contact on the second support. When closed, the moveable contact electrically connects the two stationary contacts. Bumper pads, corresponding in number and shape to the moveable contacts, are provided at a predetermined distance between adjacent moveable contacts. A spring, located between the second support and the first support and extending about the periphery of the second support, holds the second support apart from the first support and each switch open.

Abstract: A parallel path Coriolis mass flow rate meter, which incorporates improved inlet and outlet manifolds, is disclosed. Each manifold includes a transition piece and a tube mounting block. The transition piece incorporates a passageway to route fluid into or out of the meter and has a gradually changing cross-sectional area to reduce cavitation. Each tube mounting block has one end fixedly attached to a respective one of the transition pieces. The other end of the tube mounting blocks receives the parallel flow tubes. One mounting block evenly divides incoming fluid whose mass flow rate is to be determined between the parallel flow tubes while the other mounting block combines the fluid discharged from the flow tubes. Each of the tube mounting blocks is fabricated with an internal shoulder which aligns each of the flow tubes in a parallel relationship to one another and then suitably melts upon application of heat to maintain this relationship.

Abstract: A method of brazing corrosion resistant, nickel-based, thin-walled tubing which includes substantial proportions of nickel, chromium and molybdenum to a stainless steel base member using a filler metal, principally comprising gold as a major constituent and nickel as a minor constituent, in a vacuum furnace without introducing stress corrosion cracks in the brazed tubing and also avoiding carbon precipitation. The brazing is conducted at a temperature of at least about 1900.degree. F. (1038.degree. C.) for a sufficient period of time to allow any carbide precipitation formed during the heating to redissolve and also to permit full, uniform flow of the filler metal. The heated members are rapidly quenched in an inert atmosphere to a temperature at least sufficiently low to avoid carbon precipitation in the tubing.

Abstract: This invention relates to an electric arc heater process and apparatus for the essentially complete decomposition of hazardous materials including polychlorinated biphenyls. Finely divided liquid or gaseous hazardous material is injected into a primary gas stream which has been superheated in an electric arc heater. The mixture is directed into a primary reactor for complete decomposition with dwell times in the reactor being in the order of 0.05 to 0.15 seconds. The decomposition products are neutralized with the gases being released to atmosphere and any remaining particulates being collected for ultimate disposal. Large solid hazardous material is first shredded then heated in a roaster or rotary kiln to vaporize the primary gas stream. A soaking reactor is provided where increased dwell times are required for the decomposition of thermally stable compounds which may be formed in the primary reactor. When these compounds are absent the soaking reactor can be by-passed.

Abstract: An apparatus and process for the reduction in a plasma stream of a feed material including a comminuted metal oxide, a slag former and a reductant utilizing an enclosed horizontal reactor having a reduction chamber and a filter chamber therein separated by an either common partition having a plurality of holes therethrough or a refractory lined passageway. Coke filter media in the filter chamber act to filter out entrained molten metal contained in the plasma stream with the partition or passageway preventing entry of the coke from the filter chamber into the metal bath contained in the reduction chamber thereby limiting the amount of carbon entering the metal produced. Unreduced metal oxide is provided in the slag layer of the metal bath to maintain the stoichiometric ratio between the metal and reductant in the reduction chamber.

Abstract: A circuit breaker having an integral handle cover assembly for manual operation of the circuit breaker. The handle assembly comprises a cap segment and a base segment. The base segment removably engages with the operating mechanism of the circuit breaker with the cap segment positioned exterior to the circuit breaker cover and engaged with the base segment such that the handle assembly is attached to the cover while being movable in the opening thereof during the opening and closing of the circuit breaker allowing the cover to be removed from the circuit breaker without the detachment of the handle assembly from the cover.

Abstract: There is provided a static VAR generator employing a bank of series-connected inductors, each inductor being supplied by different secondary taps of a step-down transformer. The voltage rating of each inductor is appropriately decreased so as to make their sum correspond to the supply voltage. All but one of the inductors are controlled by thyristors in an on-off fashion to supply reactive power to the network in incremental steps. One of the thyristors is continuously phase-angle fired in combination with the incremental insertion of the other inductors to vary the VAR output over the full range, but generating harmonics that are proportional only to the continuously controlled inductor.

Abstract: A vacuum contactor having a compact DC electromagnet with an improved force watts ratio. The DC electromagnet consisting of a dual pickup coil and holding coil winding assembly and a solid U-shaped core having removable legs secured to a base with an adhesive backed aluminum shim positioned intermediate the legs and base, the ampere turns of the pickup coil being approximately 7.5 times those of the holding coil with the legs of the core being approximately 1/3 the length of those in a conventional DC electromagnet having substantially the same force watts ratio. The shorter legs of the core reduce magnetic losses and provide increased magnetic coupling with the moving armature of the contactor closing mechanism. This allows the smaller magnet to exert a greater force upon the armature during closing of the vacuum interrupter. With decreased magnetic losses, the size of the windings can be reduced, facilitating removal of the heat generated therein and producing a small, efficient magnet.

Abstract: A static VAR generator utilizing a multitude of reactor banks each having different computation circuits and firing angle control circuits is provided. The different computation and firing angle control circuits allows the VAR generator the flexibility of being able to change the reactor power in an A.C. network repetitively in any cycle in response to rapid changes in load demand. This is accomplished by each reactor bank having progressively longer computation times and later insertion of additional banks into the network after the first bank has responded to load demand.

Abstract: A plug-in type electric circuit breaker utilizing a detachably fastened stab assembly for interconnecting the circuit breaker to current carrying members such as bus bars. The stab assembly incorporates a plurality of opposed, independently movable spring-biased contact fingers having limited axial and arcuate motion allowing for good electrical and mechanical interconnection between misaligned circuit breakers and bus bars and reduction in the amount of force required for installation while preventing the engagement of the circuit breaker with oversized or undersized conductors.

Abstract: An electric arc heater having outlet gas admission. The mounting flange of an electric arc heater has a channel extending about its circumference which is enclosed by a detachably fastened plate to form a manifold. A passageway for the material to be admitted is provided between an outer surface of the mounting flange and the manifold. A plurality of peripherally spaced passageways are provided in the plate intermediate the manifold and the flow path of the arc heated gas exiting the arc heater outlet providing for the uniform distribution of the added material into the arc heated gas. By varying the position of these passageways a broad range of admission paths ranging from substantially parallel to the flow path of the arc heated gas to substantially perpendicular can be achieved without the use of additional downstream admission collars and seals.

Abstract: An axial magnetic field vacuum-type circuit interrupter. Provided in an evacuated housing is a pair of opposed contacts at least one of which is movable with respect to the other and is movable between a closed position in engagement with the other contact to an open position spaced apart from the other contact to form an arcing gap therebetween during circuit interruption. Each contact includes a disc-shaped backing plate having at least two radially spiraling slots therethrough and a contact and arcing ring secured to and positioned about the face of the backing plate. The backing plates are substantially parallel to one another with the direction of the spiraling slots therethrough being reversed with respect to those of the opposing contact. Because of the reversed direction of spiraling in the opposed faces of the backing plates, an axial magnetic field is created by the flow of current through the contact structure which causes the arc to remain diffuse during the circuit interruption.

Abstract: A method of preheating a ladle addition to a melt contained in an enclosed or covered ladle without significant loss of melt temperature. A gas stream is heated in a non-transferred arc electric arc heater to a temperature in excess of that of the melt. The ladle addition is introduced into the heated gas stream in the arc heater downstream of the arc heater wherein its temperature is increased to be about equal to or greater than the melt temperature. The heated gas stream and the entrained ladle addition is then introduced into the ladle. As the gas stream impinges on the melt, the ladle addition separates out and combines with the melt with the resulting off-gas being exhausted from the ladle. The off-gas can be recycled to the arc heater for reuse.

Abstract: A high power non-transferred electric arc heater utilizing interelectrode segments which create a stepped arc chamber intermediate two hollow, substantially cylindrical, axially spaced electrodes. Gas to be heated is admitted upstream of the arc chamber and between adjacent segments. Gas is used to form a cold boundary layer about the expanding core of arc-heater gas. Additional secondary gas inlets adjacent the electrode provide fluid dynamic means for arc positioning on the electrode segments. Gas pressures of less than or in the range of about 1 atmosphere to about 50 atmospheres are used with power levels of about 10 MW being possible. The stepped arc chamber facilitates arc transfer to the downstream electrodes and allows a larger diameter for the arc heated gas while the boundary layer of gas maintaining comparable spacing along the length of the arc-heated gas and the surface of the arc chamber reducing the rate of heat transfer from the arc heated gas to the segments of the arc heater.