Abstract: A printed circuit board backpanel uses stripline construction to allow emitter coupled logic. (ECL) signals and transistor-transistor logic (TTL) signals on the same signal layer, while providing electromagnetic interference (EMI) emission control.

Abstract: A pin grid array package for carrying an integrated circuit chip having input/output leads. The pin grid array package includes a carrier having a centrally located opening for carrying the integrated circuit chip, a plurality of input/output pins spaced around the periphery of the centrally located opening, interconnect leads on the carrier for connecting selected ones of the input/output pins to selected leads of the integrated circuit chip, and heat sink material around the periphery of the input/output pins which serves as a cooling-fin for efficient integrated circuit chip heat removal. Each of the plurality of input/output pins is normal to the plane of the integrated circuit chip and extends through the carrier with a first portion extending away from a first side of the carrier and a second portion extending away from a second side of the carrier.

Abstract: A terminator for a transceiver device for transmitting data signals to and receiving data signals from a second transceiver device over a transmission line therebetween. The terminator has a transmitter connected to the transmission line for transmitting data signals to the second transceiver device, a receiver connected to the transmission line for receiving data signals from the second transceiver device, a termination resistor connected to the transmission line for improving the transmission characteristics of the transmission line, and a switch device between the termination resistor and the transmission line. The switch device is closed for a portion of the time when the receiver is receiving data signals from the second transceiver device such that when it is closed the termination resistor is connected to the transmission line, and is open for the remainder to the time such that when it is open the termination resistor is not connected to the transmission line.

Abstract: A clock distribution system having a generator for generating a train of pulses, a transition circuit connected to the output of the generator for generating a clock signal having spaced apart transitions of a desired polarity, a distribution circuit distributing the clock signal to a plurality of boards which utilize the clock signal, and a flip-flop on each of the boards which utilize the clock signal. Each of the flip-flops is connected to the distribution circuit for receiving the clock signal and for generating clock pulses which are defined by the spaced apart transitions.

Abstract: An apparatus for assisting in the electrical connection and disconnection of a circuit board with an energized circuit having a power supply, a power connection electrically connected to the power supply and having a board connector for electrical connection to a circuit board to be inserted into or removed from an energized circuit, and a control circuit for controlling the power supply means. The control circuit controls the pre-charging of a circuit board to a selected voltage level prior to its insertion into a circuit, and maintains a selected voltage level on a circuit board during its removal from an energized circuit.

Abstract: A circuit for assisting transitions of a signal on a bus conductor having a sensing element connected to the bus conductor for determining if the bus conductor is in a first state or a second state, an assisting element for assisting transitions of a signal on the bus conductor between its first state and its second state responsive to electrical clock pulses, and a logic element connected to the sensing element and the assist element for enabling said assist element when the transmission of the mentioned signal is from its first state to its second state during said clock pulses, and for disabling the assisting element when the mentioned signal transition is from its second state to its first state during said clock pulses.

Abstract: A circuit board component, specifically a capacitor, which is configured to be machine insertable into apertures of a circuit board. The component is a cylindrical element having at least two recessed sectors in the outer surface of the cylindrical element which recessed surfaces are provided with an electrically conductive material. The conductive material either forms a part of the component such as capacitor plates and/or provides a contact surface for the connecting of an internally-mounted electrical component. An indexing means positioned on the one end of the cylindrical element provides a means whereby an automatic insertion machine can by indexing insure the correct orientation of the component with regard to corresponding electrical contacts on the circuit board. A flange extending from one end of the cylindrical element provides a stop in order to limit the travel of the component within the circuit board aperture when inserted by automatic means.

Abstract: A circuit board component, specifically a capacitor, which is configured to be machine-insertable into apertures of a circuit board to make a solderless electrical connection to electrical conductors positioned on and in the circuit board. The component is a cylindrical element which has portions of its outer surface affixed with an electrically conductive material which material is formed with a plurality of serrations. The serrations are designed to cut through and to make a force fit, gas tight, seal with the walled portions and the electrical conductors of a circuit board. The electrically conductive material also either forms a part of the component, such as capacitor plates and/or provides a contact surface for the connecting of an internally-mounted electrical component. An indexing means positioned on one end of the cylindrical element provides a mechanical indexing to insure the correct orientation of the component with regard to corresponding electrical contacts on the circuit board.

Abstract: A low-cost electromagnetic interference (EMI) gasket for light-weight equipment enclosures. A pliable strip of electrically conductive material is wrapped spirally about a flexible laminar core structure comprising foam and permanent magnet elements. The gasket is emplaced between two conductive surfaces forming portions of an EMI shield, one of which surfaces is attractive to the magnetic element of the gasket.