Abstract: An autoselecting interface for selectively connecting an input aircraft power source to one of two outputs according to a sensed voltage of the input aircraft power source comprises a pair of input terminals for connection to aircraft power sources; first and second pairs of output terminals; a first voltage sensor connected to the input terminals for producing a first trigger output when an AC aircraft voltage is present at the input terminals; a second voltage sensor connected to the input terminals for producing a second trigger output when a DC aircraft voltage is present at the input terminals; a first switch responsive to the first trigger output for electrically connecting the pair of input terminals to the first pair of output terminals; a second switch responsive to the second trigger output for electrically connecting the pair of input terminals to the second pair of output terminals; and an override circuit for disabling the second voltage sensor from producing the second trigger output when an AC
Abstract: This invention provides for separating undesired signals from spectra of desired signals in a communication system. Specifically, a communication system for transmitting and receiving spectra of signals having undesired signals and desired signals comprising: a transceiver system; a TEE-junction coupled to the transceiver system and having first and second ports, the undesired and desired signals being separated at the TEE-junction; an Off-line signal interference reduction device coupled to the first port, the Off-line signal interference reduction device receiving the undesired signals from the first port; and an In-line signal interference reduction device coupled to the second port and an antenna system.
Abstract: A diagnostic tester evaluates at least one inputted test signal corresponding to test data relating to at least one predetermined parameter of a system being tested, to produce first and second candidate signals corresponding respectively to first and second possible diagnoses of the condition of the system respectively having the first and second highest levels of certainty of being valid, and first and second certainty signals corresponding respectively to values of the first and second highest levels of certainty. The diagnostic tester further determines the sufficiency of the testing that has taken place responsive to the first and second certainty signals, and produces an output signal indicative of whether sufficient test data has been evaluated to declare a diagnosis. Preferably, an uncertainty signal corresponding to a measure of the uncertainty that the evaluated at least one test signal can be validly evaluated is also produced and used to produce the output signal.
September 14, 1990
Date of Patent:
July 14, 1992
Arinc Research Corporation
John W. Sheppard, William R. Simpson, Jerry L. Graham
Abstract: A remote parameter monitoring system utilizes a series of half-wave rectifier diodes in combination with a unique overlapping wiring arrangement to provide for location-specific detection of a parameter condition existing at a plurality of spaced locations. In one embodiment of the invention, the system is used for monitoring cracks in helicopter rotor blades and indicating to the crew in the cockpit both the fact of a cracked blade and the specific blade which is cracked. In such embodiment, the system includes a three-phase alternating current transformer whose primary windings are supplied by the helicopter's three-phase alternating current generators and whose secondary windings make up part of the wiring loops between the cockpit and the rotor blades. By controlling currents flowing in opposite directions in the wiring loops, the system allows for blade-specific crack detection of up to six rotor blades by means of only three wires between the rotor blade assembly and the cockpit area.
Abstract: A digital data communications system employing correlation detection is disclosed as comprising an encoding system which encodes successive k-bit data words from a data source into predetermined start-stop phases of either a 2.sup.k -bit repeating pseudorandom binary code or a 2.sup.k -l bit repeating pseudorandom binary code and a decoding system which receives the stream of ones and zeros in the pseudorandom binary code from the encoder and reproduces therefrom, using a correlation detector and associated circuitry, a replica of the original k-bit data word from the data source.
Abstract: A digital data communications system employing correlation detection is disclosed as comprising an encoding system which encodes successive k-bit data words from a data source into predetermined start-stop phases of either a 2.sup.k -bit repeating pseudorandom binary code or a 2.sup.k -1 bit repeating pseudorandom binary code and a decoding system which receives the stream of ones and zeros in the pseudorandom binary code from the encoder and reproduces therefrom, using a correlation detector and associated circuitry, a replica of the original k-bit data word from the data source.
Abstract: A shaft coupling system for accommodating axial displacement and angular misalignment between two shafts. A hollow bushing is force fit into the hollow end of a first shaft. The bushing is provided with a plurality of part-circular recesses on its inner surface. A spline adapter is slip-fit onto a second shaft. The spline adapter cooperates with the bushing, and has spline teeth extending from its outer surface which are substantially boat-shaped. The shape of the teeth allows for extra clearance at the ends of the coupling system, which is necessary to accommodate angular misalignment. The bushing is made of readily replaceable and relatively inexpensive plastic materials.
Abstract: A long wearing shaft coupling is comprised of metallic male and female members, and a plastic insert. The plastic insert is interference fitted into the female member, and the male member is slip fitted into the insert. The male member is provided with a number of part-circular shaped in transverse cross-section, radially outwardly extending projections which correspond to an equal number of similarly shaped and situated recesses in the insert. The plastic insert transmits the load between the male member and the female member, and is readily replaceable. The projections can be of a slightly smaller radius than the recesses, to allow for misalignments in the shaft. The slip fit nature allows for easy disassembling of the coupling.
Abstract: A distance measuring system is provided including a ground station transponder continuously transmitting a repeating pseudorandom coded bit pattern, and at least one aircraft interrogator receiving and locking onto the ground station signal. The aircraft interrogator transmits a coded interrogation signal in precise synchronism with an arbitrarily selected any one of the repetitive code words (bit patterns) that comprise the repeating pseudorandom coded bit pattern which are coded identically with the interrogation signal and waits for a reply. If the ground station receives the coded interrogation signal in synchronism with an identically coded word in its continuous transmission, it transmits a reply signal to the aircraft interrogator optionally encoded with synchronism error or interrogation steering information.