Abstract: A telescope and accessory coding system and method includes the association of a unique respective icon, color, or other symbol with each one of a number of optical accessory types which are usable with a telescope, either alone or in optical series with other accessory types. A representation of the symbol which represents that accessory type is placed on each accessory of that type. Furthermore, each accessory of an accessory type which is capable of receiving other accessory types has placed thereon representations of symbols representing those other accessory types which are optically compatible therewith.

Abstract: A penta mirror diagonal and zoom lens assembly for refracting or catadioptric astronomical telescopes includes a specially adapted zoom lens with a key extending outward from an objective lens and an adaptor designed for insertion and retention in a viewing end of an astronomical or catadioptric telescope. The adaptor includes a keyway which mates with the key on the zoom lens, thus allowing the zoom lens to be used only with the adaptor. The zoom lens itself is specially designed for use with astronomical or catadioptric telescopes.

Abstract: An apparatus and method is provided for controlling the insertion of one or more special insert sheets into a steam of regular imaged sheets. A coded sheet is placed into a sheet stack in a position where an insert sheet is to be placed. Sheets are removed from the stack one by one and transported along a path past a sensor toward a finishing apparatus. When the sensor detects a coded sheet, the coded sheet is diverted from the stream and later replaced with an insert sheet.

Abstract: Radiation-curable coating compositions which form transparent, abrasion-resistant tintable coatings upon curing by exposure to high intensity irradiation, such as ultraviolet light or electron beam irradiation. The coating composition comprises a combination of effective amounts of (a) colloidal silica, (b) the hydrolysis product of a silane compound having a polymerizable functional group such as acryloxy-functional silanes or glycidoxy-functional silanes or mixtures of both, (c) polyfunctional, polymerizable, non-acrylate-functional ethers, (d) at least one radiation sensitive initiator and, preferably, (e) a monofunctional monomer. When the surface of a substrate coated with the cured coating composition is immersed in a colored dye bath for a sufficient period of time, the coating absorbs or transmits to the substrate a desired amount of dye.

Abstract: Radiator-Curable coating compositions which form transparent, abrasion-resistant, tintable coatings upon curing by exposure to high intensity irradiation, such as ultraviolet light or electron beam irradiation. The coating composition comprises a combination of effective amounts of (a) colloidal silica, (b) the hydrolysis product of a silane compound having a polymerizable functional group such as acryloxy-functional silanes or glycidoxy-functional silanes or mixtures of both, (c) polyfunctional, polymerizable, non-acrylate-functional ethers, (d) at least one radiation sensitive initiator and, preferably, (e) a monofunctional monomer. When the surface of a substrate coated with the cured coating composition is immersed in a colored dye bath for a sufficient period of time, the coating absorbs or transmits to the substrate a desired amount of dye.

Abstract: A shunt three-phase wye-connected capacitor bank is connected intermediate a substation transformer and any source of zero-sequence power line carrier communication signals being transmitted on the substation distribution network to partially alleviate unbalance conditions in the communication signals which in the balanced condition are not passed by a three-phase substation transformer to the main transmission line. The signal is further attenuated by connecting the common wye-point of the capacitor bank through an inductance to neutral to form a shunt element of either an L or pi attenuation circuit with the series inductance of the substation transformer and the transmission line inductance forming the serial elements of the L or pi circuit. A further shunt element at another substation distribution network completes the attenuation circuit for the pi configuration.

Abstract: A communication signal is coupled simultaneously to all three phases of a three-power line through a three-phase open delta transformer with the communication signal being applied across the low voltage pair of windings.

Abstract: A circuit is described for bi-directionally coupling a communication signal around a distribution transformer. The circuit includes a single-phase coupling transformer with a primary to secondary voltage ratio approximately equal to that of the distribution transformer. A capacitor is connected to one of the secondary terminals of the coupling transformer. The capacitor is chosen so that the series circuit including the capacitor, the self inductance of the coupling transformer and, possibly, the series inductance of interconnecting lines is resonant at the carrier frequency of the communications signal. The series combination of the capacitor and the secondary of the coupling transformer can be connected between two of the conductors on the secondary side of the distribution transformer which are selected for communication signal propagation.

Abstract: A circuit for bi-directionally bypassing a delta-wye transformer with a balanced phase-to-neutral power line communications signal, using passive components. The circuit includes a set of three capacitors connected in a wye configuration, each having one side connected to one of the three phase power lines on the delta side of the transformer. The circuit further includes a network connected from the node of the wye configuration of capacitors to the neutral conductor or conductors associated with the power lines on the two sides of the delta-wye transformer. The network includes a single phase transformer, as well as a capacitance connected from the secondary of this transformer to the node of the wye of the delta-wye transformer. The network further includes an inductive reactor connected from the neutral on the wye side of the delta-wye transformer to the node of the wye transformer.

Abstract: A circuit is disclosed for coupling a power line communications signal between two three-phase power lines, with the signal being transmitted in a balanced phase-to-neutral mode on the first line and in a phase-to-phase mode on the second line. The circuit includes two coupling transformers, one open-wye to open-delta, and the other open-delta to open-delta. The primary of one of the transformers is connected to one of the three-phase lines, while the primary of the other transformer is connected to the other three-phase lines. The secondaries of the transformers are connected together at one terminal of each and interconnected by a capacitor at the other terminal of each. Signal and power voltage ratios between the two power lines are matched, and the capacitor is selected to provide series resonance in the secondary loop of the coupling circuit at the power line communications signal carrier frequency.

Abstract: Circuits for bi-directionally bypassing a delta-wye transformer with a balanced phase-to-neutral power line communication signal, using passive components. The circuits include a set of three capacitors connected in a wye configuration, each having one side connected to one of the three-phase power lines on the delta side of the transformer. The circuit further includes a network connected from the node of the wye configuration of capacitors to neutral, the network including an inductive reactor with one side connected to neutral and the other connected to the node of the wye windings of the transformer. Component values are selected so that the circuit is resonant from the three phase lines on the delta side of the transformer to neutral. Further, the voltage transformation ratio of the communication signal from the delta side to the wye side is made the same as the corresponding power voltage ratio of the transformer.

Abstract: A communication signal is coupled simultaneously to all three phases of a three-phase power line through a three-phase open delta transformer with the communication signal being applied across the low voltage pair of windings.

Abstract: Multiplexed carrier signals modulated with digital data are transmitted through a medium polluted with harmonic signals by asymmetrically positioning the frequency of one of the carrier signals between two of the adjacent system harmonics, modulating that carrier signal with digital data at a baud rate so that the spectral density nulls of the modulated carrier signal in the frequency domain coincide with the two adjacent system harmonics to which spectral distribution the detector response is matched, generating at least one additional carrier signal whose frequency is also positioned between the two same adjacent system harmonics but is different from that of the other carrier signal and whose frequency separation from any adjacent carrier signal is equal to the baud rate or some multiple thereof, and modulating each additional carrier signal with digital data at the same baud rate.

Abstract: A communication signal is coupled simultaneously to all three phases of a neutral-wye three-phase power line through a transformer arrangement consisting of a low voltage set of three serially connected windings across which the signal is applied to produce the same current in all three windings and a high voltage set of three windings which are connected in a neutral-wye configuration to the power line with a winding of each set being magnetically coupled to a different winding of the other set such that the currents induced in all three windings of the high voltage set flow in the same direction with respect to the neutral connection.

Abstract: A differentially encoded carrier signal is synchronously detected by generating an output signal indicative of the carrier signal characteristic in each transmitted bit interval during the interval, storing it so that in the next bit interval it can be compared against the output signal for the immediately preceding transmitted bit interval to establish the characteristic differential to demodulate its information and forcing the output signal to zero in a subsequent bit interval after first using it as a reference for comparison with the output signal for the immediately succeeding transmitted bit interval to demodulate its information.