Abstract: A loopback enabled by an instruction and address code pair transmitted with the regular data stream affords a simplified fault location scheme for a T1 repeater span. By selecting unique addresses for each repeater using a predetermined frame sequence and by testing for logic error density, erroneous enablement is avoided.

Abstract: An improved reed relay having a bobbin, an operating coil wound around the bobbin and at least one reed switch contained within the bobbin. The reed switch has a hermetically-sealed glass capsule that contains an atmosphere of dry inert gas. The capsule also contains two long thin contact blades having terminations extending from respective ends of the capsule. A first contact blade acting as the armature is formed at its contact end with multiple prongs, each prong containing a contact pad. The second contact blade acts as the fixed contact. The contact pads surround the contact end of the second blade so as to contact, during operation of the relay, a different surface area of the second blade. The prongs may be formed in any desired geometric arrangement (e.g., rectangular, triangular, etc.) to surround the contact end of the second contact blade.

Abstract: A method of making a monolithic structure for an optocoupler that provides improved linearity. The method includes forming an output signal photodiode and a feedback control signal photodiode on a single chip with an LED. The photodiodes are configured and positioned relative to the LED to compensate for any non-uniformities in the light received from the LED.

Abstract: A data access arrangement (DAA) having a transhybrid circuit for separating a transmit signal from a received signal by providing a transmit cancellation signal to the inverting input of a servo-feedback differential amplifier on the receive channel of the DAA. The cancellation signal is provided by a photodiode optically coupleable with a light emitting diode within a optical isolator on the transmission channel of the DAA. The gain of the cancellation signal can be independently controlled.

Abstract: A method of establishing a contact arrangement for a reed switch. The method increases the number of contact surfaces between the armature and the fixed contact by providing the fixed contact with a contact end that has multiple prongs and positions the armature and the fixed contact so that the prongs surround the armature. The method also adjusts the armature and the fixed contact so that there are prongs that contact the armature when the armature moves from the rest position during switch operation and prongs that provide additional multi-planar contact surfaces for the armature in the event that the armature and the fixed contact prematurely separate during switch operation.

Abstract: A mobile call processing methodology and concomitant system based on ISDN/CACH-EKTS technology which can broadcast incoming calls to base stations (e.g., 1050) and which uses the ISDN/CACH-EKTS bridging technology to handle base station handoff of an established call. Each mobile user (e.g., 1041, 1042) is assigned a unique EKTS directory number as well as a unique call appearance identifier, which allows for the handling of multiple call appearances of the unique DN on a single base station. For a given mobile communication application, the central office (e.g., 1014) treats the base station as an ISDN/CACH-EKTS terminal.

Abstract: Bidirectional isolated interfaces using optical couplers offer a compact and cost-effective alternative to traditional line transformers. The devices can be configured to provide half-duplex or full-duplex communication.

Abstract: An optically triggered silicon controlled rectifier (SCR) circuit (20) has a number of semiconductor layers diffused into an N- substrate (21). The layers form an SCR (50) having a P+ anode region (25), a P+ gate region (24), and an N+ cathode region (27). An adjustable base-shunt resistance, in the form of a P- channel depletion mode MOSFET (Q3), connects between the SCR gate region and the cathode region. The MOSFET includes a MOSFET gate region (35), a P+ drain region (24), a P-- channel (26), and a P+ source region (23). The substrate also accommodates a PN photodiode (22, D1) which connects to the MOSFET gate region for switching the MOSFET on and off in response to incident optical radiation (L) thereon. The SCR gate region also comprises photosensitive material. When sufficient optical radiation illuminates the photodiode and the SCR gate region, the MOSFET is turned off and the SCR is triggered, permitting anode-to-cathode current to flow.

Abstract: An optically-triggered silicon controlled rectifier (SCR) device (21) mounted on a lead frame (34). The SCR device contains a cathode layer (24), an optical gate or control layer (23), and an anode layer (31) formed on a semiconductor substrate (22). The device is soldered onto a pedestal (33) formed on the lead frame. To connect the device to the lead frame, solder is deposited upon the anode layer and the solder fixes the anode layer to the pedestal on the lead frame. The pedestal may be formed by etching or stamping a depression (35) in the lead frame. The device is centered on the pedestal such that the edges of the device are located adjacent the depression, and are spaced from the lead frame.

Abstract: An optically-coupled line receiver that handles multiple-state signals on data communications lines by using a differential circuit at the input.

Abstract: By using the linear behavior of optical emitters, one can provide an optically-coupled data communications line driver that directly interfaces with differential circuits. A single emitter provides multi-level signals avoiding the need for separate discrete devices.

Abstract: Optical feedback control in an optical emitter-detector combination can be improved by fabricating the two devices on a single substrate. The feedback radiation can then travel within a monolithic structure. This arrangement will yield greater uniformity in devices as well as provide for easier mechanical assembly.

Abstract: An optically triggered silicon controlled rectifier (SCR) circuit (20) has a number of semiconductor layers diffused into an N- substrate (21). The layers form an SCR (50) having a P+ anode region (25), a P+ gate region (24), and an N+ cathode region (27). An adjustable base-shunt resistance, in the form of a P- channel depletion mode MOSFET (Q3), connects between the SCR gate region and the cathode region. The MOSFET includes a MOSFET gate region (35), a P+ drain region (24), a P-- channel (26), and a P+ source region (23). The substrate also accommodates a PN photodiode (22, D1) which connects to the MOSFET gate region for switching the MOSFET on and off in response to incident optical radiation (L) thereon. The SCR gate region also comprises photosensitive material. When sufficient optical radiation illuminates the photodiode and the SCR gate region, the MOSFET is turned off and the SCR is triggered, permitting anode-to-cathode current to flow.

Abstract: An optically-triggered silicon controlled rectifier (SCR) (21) having a number of semiconductor layers (23, 24, 31) diffused into an N type substrate (22). Specifically, the SCR is formed by diffusing a first P+ layer (23) into an upper surface of the substrate. Then, an N+ layer (24) is diffused into a portion of an upper surface of the first P+ layer. An oxide layer (25) which is permeable to optical radiation is formed on the first P+ layer. A conductive cathode terminal (26) is then deposited on the N+ layer. Therefore, a trench (30) is etched in the lower surface of the substrate. The trench is defined by a depth and a surface. A second P+ layer (31) is diffused into the surface of the trench. The depth of the trench substantially defines a spacing between the first and second P+ layers. The chip is soldered onto a pedestal (33) formed on a lead frame (34). The solder is deposited in the trench and contacts the second P+ layer to form an anode terminal (36).

Abstract: A cutout is formed through a panel for providing a closed slot or channel surrounding a cleat having a tee shape, for receiving a midportion of a tie wrap inserted through the slot on one side of the panel to a position over a narrowed neck portion of the cleat, thereby permitting a component placed over the cleat on the one side of the panel to be secured thereto by tightening the tie wrap around both the cleat and the component, without requiring access to both sides of the panel.

Abstract: A method of manufacturing a printed circuit board (PCB) for interconnecting integrated circuit devices includes a lead frame sandwiched between two multilayer substrates. Integrated circuit devices are mounted on the top of the upper substrate and on the bottom of the lower substrate to provide increased packaging density. Thus, according to the present invention, it is possible to provide a simply constructed electronic component mounting PCB which facilitates the design of circuits, and affords excellent connection reliability, which can readily form a heat radiating structure, and in which the thermal matching with the electronic component is excellent.

Abstract: An optically-triggered silicon controlled rectifier (SCR) device (21) mounted on a lead frame (34). The SCR device contains a cathode layer (24), an optical gate or control layer (23), and an anode layer (31) formed on a semiconductor substrate (22). The device is soldered onto a pedestal (33) formed on the lead frame. To connect the device to the lead frame, solder is deposited upon the anode layer and the solder fixes the anode layer to the pedestal on the lead frame. The pedestal may be formed by etching or stamping a depression (35) in the lead frame. The device is centered on the pedestal such that the edges of the device are located adjacent the depression, and are spaced from the lead frame.

Abstract: A method of growing optical quality beta barium borate; crystals from a pure NaCl fluxed melt. The method comprises maintaining particular thermal field conditions throughout the melt and slowly cooling the melt to cause beta barium borate to crystallize from the melt. The rate of cooling may be at a rate of not greater than 3.degree. C. per day. The method may utilize a seed crystal, suspended into the melt, so that the beta barium borate may crystallize on the seed crystal.

Abstract: A PCB relay comprising a housing having a bottom side, a top side and a circumferential wall and terminal pins protruding from the bottom side for being contacted to a printed circuit board. For conducting heavy load currents from the relay contacts and away from the printed circuit board in a quick manner and via a short pathway, at least two conducting strips are fastened to the circumferential wall of the housing, extending from the bottom side to the top side. The strips form soldering pins at the bottom end thereof and quick-connect plugs or terminals at the top end thereof. An electrically conducting connection between the strips and the terminal pins of the relay may be formed on the PCB or, alternatively, the elements may be directly connected to one another.

Abstract: A new compositional relationship in the starting charge of a crystal growth station (FIG. 1 ) provides homogeneous monocrystalline lithium niobate. A new measurement system (FIG. 2 ) provides Curie point values of significantly greater accuracy then that of conventional measurements. Careful control of the starting charge composition for crystal growth and effective utilization of the measurement system enable the determination of the compositional range of starting charges for producing congruent crystalline production. The composition corresponds to a mol percentage of 48.35.+-..01 to 48.40.+-..01 of Li.sub.2 O and the remainder Nb2.sub.O 5 for producing homogeneous crystal whose solidification fraction of the molten charge exceeds that which was heretofore achievable.