Abstract:
Agencement permettant d'effectuer un test d'une boucle d'abonné par l'intermédiaire d'un dispositif de concentration/expansion (17) utilisant des points de croisement de semiconducteur. Les points de croisement (46, 47, 48) du dispositif de concentration/expansion sont relativement non-linéaires lorsqu'ils conduisent des courants inférieurs à un courant prédéterminé et sont relativement linéaires lorsqu'ils conduisent des courants supérieurs au courant prédéterminé. Lorsque des tests doivent être appliqués sur une boucle donnée (13) d'un abonné qui comprend un conducteur de pointe et un conducteur annulaire, deux circuits ou voies sont complétés par l'intermédiaire du dispositif de concentration/expansion (17) sur le conducteur de pointe et deux voies sont complétées par l'intermédiaire du dispositif de concentration/expansion sur le conducteur annulaire. Une source de linéarisation (26) transmet ensuite un courant dépassant le courant prédéterminé autour des circuits formés par les deux voies de concentration/expansion vers chaque conducteur de la boucle d'abonné. Des signaux d'essai sont ensuite appliqués vers la boucle d'abonné (13) en connectant ces signaux entre les deux voies vers le conducteur annulaire d'abonné et les deux voies vers le conducteur de pointe d'abonné.
Abstract:
Un dispositif de commutation à semiconducteur bidirectionnel à deux bornes comprend un corps en matériau semiconducteur de silicium ayant dans une partie un élément de commutation à cinq zones (17, 13, 14, 15, 18) et, dans une autre partie solidaire, un élément de rupture bidirectionnel sensible à la tension à trois zones (20, 19, 13), des moyens comprenant une autre partie du corps établissant la connexion entre l'élément à trois zones jouant le rôle d'un élément de portillonnage et cet élément à cinq zones de manière à déclencher la conduction bidirectionnelle lorsqu'une interruption de tension se produit dans l'une ou l'autre direction dans l'élément à trois zones.
Abstract:
Method for preserving the solderability of copper conductors by stabilizing a cleaned, mildly etched conductor surface with a phosphoric acid - glycol solution then immersing the surface in imidazole followed by a rinse to remove excess imidazole.
Abstract:
Certain mask materials, such as gold, are difficult to remove without damaging the underlying workpiece. This problem is solved in a process wherein, as a first step, a "parting" layer (44) of a metal selected from the group consisting of nickel, aluminum, indium and tin is applied to the substrate (10) to be masked. Over the parting layer is applied the masking layer (22). After processing, the parting layer (44) is treated to detach it along with the mask from the substrate. For proton bombardment of a substrate which included gallium arsenide, the parting layer is preferably nickel, the mask is preferably gold, and the detaching agent includes hydrochloric acid.
Abstract:
Channel unit (109) for connecting a carrier channel multiplex or tie line directly to a terminating unit line such as that terminating a private branch exchange (102) or a telephone station set (117) thereby eliminating the normal local end office interconnection. In particular, the channel unit interfaces the different signaling protocols of the interconnected lines and generates call progress control signals such as dial tone and audible ringing which are normally generated by the local end office. The channel unit comprises a converter (205) for each line for converting the electrical interface signals representative of the busy and idle conditions of the line to logic levels also representative of the busy and idle conditions of the line. A predetermined series of these logic levels form a control signal that indicates the state of a call on the line. Since the control signal indicative of the state of the call on one line is typically not useable by the other line, a microprocessor (204) included in the unit generates a second control signal to advance the state of the call on the other line to an equivalent call state. An additional converter (205) then converts the logic levels of this second control signal to the electrical interface signals of the other line to advance the state of the call to the equivalent call state. The unit further comprises a receiver (201) and transmitter (202) for exchanging dial pulse and dual tone multifrequency address signals between the lines. Also, included are circuits (203, 226) for applying call progress control signals such as dial-tone, audible ringing, and power ringing to the lines.
Abstract:
Method and apparatus for displaying special service information at a selected station during a silent interval between ringing. The apparatus, a data receiver (100), is connected to the tip and ring leads of any well-known station set and comprises a line interface unit (101), a converter (102), a control circuit (103), and a display unit (126). A frequency shift keyed (FSK) signal which represents the special service information is filtered from the ringing signals by the line interface unit. The converter detects the FSK signal and demodulates the special service information from the FSK signal. Upon detection of the FSK signal, the control circuit receives and stores the special service information. The stored special service information is then periodically sent to the display unit to begin exhibiting the information during the silent interval before the next ringing signal.
Abstract:
In a data communication network (100) wherein using units (104-111) contend for access to the network communication bus (160), data links (101, 103) interface using units located remotely from the bus to the bus for communication such that the distances between the using units and the bus are rendered functionally transparent from the viewpoint of the bus. A data link (102) includes a network interface circuit (117) connected to and located near the using unit (108) for buffering communications passing between the using unit and the bus, a data transfer controller circuit (151) connected to and located near the bus for communicating on the bus on behalf of the using unit according to the communication protocol of the bus, a local fiber optic extension circuit (141) connected to and located near the data transfer controller circuit for emulating thereto the network interface circuit, a remote fiber optic extension circuit (125) connected to and located near the network interface circuit for emulating thereto the data transfer controller circuit, and an optical fiber link (131) connecting the fiber optic extension circuits.
Abstract:
Magneto-electric devices producing an electrical signal in response to a change in a magnetic field may preferably produce uniform pulses independent of the rate of change of the magnetic field. Devices of this type have been made using the so-called Wiegand effect, but such devices are not as sensitive as those used having amorphous magnetic material. Devices made of ferromagnetic metallic element (13) usually have essentially amorphous structure which has been plastically deformed by cold deformation, are more likely to prevent a device from responding to strong magnetic fields such that these devices are more sensitive. Among those devices having a ferromagnetic element are keys, credit cards and proximity sensors.
Abstract:
High density time division busses suffer from many problems, one of which is that impedance discontinuities (LO, CB; Fig. 10) cause signal reflections to occur along the bus. These reflections, in turn, affect the settling time and noise margins of the bus and thus reduce the time "window" in which valid signals may be received. There is disclosed a transmission bus structure (Fig. 12) which allows for bidirectional, multi-port operation by using current drivers (Do/, D1, D3) instead of the traditional voltage drivers for placing data signals on the bus (Lo/, L1, L3). The transmission bus is designed in a manner which allows transmission and reception from a signal clock (501; Fig. 5) on the same clock edge, thereby substantially increasing the time allowed for transmission response and also simplifying the clock distribution requirements (Fig. 12).
Abstract:
A combinational logic device, such as a AND gate (21), is connected to control the flow of information along a wordline (W1...Wn) from the AND plane (11) to the OR plane (14) of a PLA (programmed logic array). To each such combinational logic device is applied an input signal (W) from a source external to the PLA, so that the PLA's output can respond relatively quickly to this input signal-- that is, the PLA is capable of relatively quick decision making.