Abstract: A current mode data communication system is disclosed in which the system data bus is formed by an unshielded twisted wire pair (12). Coupled to the data bus by bus couplers (16) and bus-to-stub couplers (80) are current mode data stubs (82), which also are formed by pairs of twisted, unshielded wires (84 and 86). One or more interface-to-stub couplers (88) are inductively coupled to each curretn mode data stub and, in addition, are connected in signal communication with one of the system utilization devices (10). Data signals propagating along the system data bus (12) are coupled to each utilization device (10) via an associated bus coupler (16), bus-to-stub coupler (80), and interface-to-stub coupler (88) without reflecting the signal into the system data bus (12).

Abstract: A method and apparatus for communicating rectangular form binary data over a data bus is disclosed. Prior to being sent, the data is converted by transmit couplers from rectangular form into doublet form, i.e., a single high frequency sinusoidal doublet is created for each transition of the rectangular form data signal. The doublets are applied to the data bus, and receiver couplers connected to the bus change the data from doublet form back into its original rectangular form. Preferably, the data bus is a current mode data bus 31 formed by a pair of twisted wires. Transmit and receive couplers 37 and 39 connected to utilization devices 33 (i.e., devices that originate and/or use the binary data) couple the utilization devices 33 to the twisted wires via coupler transformers 47 and 49. Also, preferably, the data produced and used by the utilization devices 33 is in Manchester biphase form.

Abstract: A receive coupler for a binary data communication system that transmits signals in rectangular waveform on a data bus (11) is provided. The receive coupler includes a transition and polarity detector (17) that differentiates received signals and produces an output pulse on one or the other of two output lines (21a and 21b) for each transition of the received signal, the output line being dependent upon the rise-fall direction of the transition. That is, rise transitions create pulses on one output line (21a) and fall transitions create pulses on the other output line (21b). The receive coupler also includes reconstruction logic (19) connected to the output lines of the transition and polarity detector (17) that reconstructs the receive signal based on the pulses. The pulses are created in the transition and polarity detector by two differentiator-comparator combinations.

Abstract: An all-electric powered flight control system for an aircraft incorporating fault-tolerant avionics combined with a redundant power actuation control system utilizing electro-mechanical devices for actuating aerodynamic control surfaces; and wherein, the redundancy is implemented through the division of the total aerodynamic surface area to be actuated into multi-segments, with each control segment having its own channel in the avionic control system. The avionic control system is effective in minimizing the effects of power actuated control loads reacting through aircraft structure by the incorporation of an electronic gain control power module which is positioned between the power output side of an actuator (e.g., an electro-mechanical or electro-hydraulic device) and the aerodynamic control surface or segment being actuated.

Abstract: An all-electric powered flight control system for an aircraft incorporating fault-tolerant avionics combined with a redundant power actuation control system utilizing electro-mechanical devices for actuating aerodynamic control surfaces; and wherein, the redundancy is implemented through the division of the total aerodynamic surface area to be actuated into multi-segments, with each control segment having its own channel in the avionic control system. The avionic control system is effective in minimizing the effects of power actuated control loads reacting through aircraft structure by the incorporation of an electronic gain control power module which is positioned between the power output side of an actuator (e.g., an electro-mechanical or electro-hydraulic device) and the aerodynamic control surface or segment being actuated.

Abstract: A data communications system which includes a plurality of terminals TL.sub.1 -TL.sub.5) and a data bus (DB), wherein each of the terminals has autonomous access to the data bus. Each terminal includes a receiver (114) which is normally enabled to receive messages on the data bus and which provides a signal (ADA) signifying the absence of messages. A transmitter (120) within each terminal includes a protocol control unit (140) which enables the transmitter to initiate message transmission only upon (i) the detection of an absence of messages on the data bus whose duration substantially equals that of a sync gap that is common to all of the terminals, and (ii) the subsequent detection of an absence of messages on the data bus whose duration substantially equals that of a terminal gap that is unique to the terminal, with the duration of the sync gap being greater than the duration of any terminal gap.

Abstract: A current mode data or power bus which provides communication between two or more terminal devices over a common, single-channel medium. The data bus comprises a pair of wires, twisted to form a succession of loops and short-circuited at both ends, together with an arbitrary number of bus couplers, one for each terminal. The bus couplers are formed by separate, disengageable core elements. Each bus coupler is inductively coupled to the twisted wire pair by inserting one or more core legs of the bus coupler through adjacent loops in the twisted wire pair; each wire loop around a core leg then constituting a one-turn transformer winding of the coupler. In this manner, separate terminals can be readily coupled to or decoupled from the current mode data communication bus without the need for making spliced, galvanic connections. This bus configuration is readily adaptable to single or multiphase power transmission.

Abstract: A data communication system which includes a plurality of terminals and a data bus, wherein each of the terminals has autonomous access to the data bus. Normally, all terminals are enabled to receive messages on the data bus. To prevent the simultaneous transmission of messages by two or more terminals, each terminal continuously monitors the data bus and is enabled to transmit a message only when the data bus has been silent, e.g., there is an absence of messages on the data bus, for a predetermined period of time which is unique to the terminal, and when a periodic transmission interval for the terminal has been reinitiated. The periodic transmission interval is substantially the same for all terminals, and is measured at each terminal from the time of a previous message transmission thereby.