Abstract: A DC bus for use in a power module has a positive DC conductor bus plate parallel with a negative DC conductor bus plate. One or more positive leads are connected to the positive bus and are connectable to a positive terminal of a power source. One or more negative leads are connected to the negative bus and are connectable to a negative terminal of a power source. The DC bus has one or more positive connections fastenable from the positive bus to the high side of a power module. The DC bus also has one or more negative connections fastenable from the negative bus to the low side of the power module. The positive bus and negative bus permit counter-flow of currents, thereby canceling magnetic fields and their associated inductances, and the positive and negative bus are connectable to the center portion of a power module.

Abstract: A repeater, useable for connecting switches in a data communication network, is provided in a distributed and/or modular fashion. The repeater includes a plurality of separate and distinct components or modules connected to or at least partially housed in, the various switches which the repeater modules couple. Preferably, the repeater autodetects and/or autoconfigures some or all aspects of repeater operations, such as detecting and/or configuring in response to appropriate or approved cable-type connections. A conductive, sealing member on a cable connector substantially reduces or eliminates EMI.

Abstract: A switching circuit useful in a binary demand feedback DC converter having multiple DC outputs which are all independently regulated using a binary on/off technique is disclosed. A comparator associated with each output compares the voltage at a given output with a reference voltage for the respective given output and generates a first signal the moment the output voltage exceeds the reference voltage. Responding immediately to the first signal a switch opens the converter transformer secondary winding associated with that output from a rectifier and filter. The voltage at that output is determined by the voltage across a capacitor in the filter and the capacitor commences discharging to be below the reference voltage at which time the first signal ceases and the switch reconnects the secondary winding to the rectifier and filter to recommence charging the filter capacitor.

Abstract: A radioshielded assembly contains components that require a d.c. supply and a multi-pole terminal arrangement connected between power supply terminals of the components and an external d.c. supply. At least one pole of the multi-pole terminal arrangement is fashioned for conducting a potential that differs from a reference potential. A switching stage is inserted between that pole of the terminal means that does not carry reference potential and the corresponding power supply terminals of the components. An actuation arrangement is in interactive communication with the switching stage, as a result of which the connected pole can be electrically connected to the power supply terminals or the pole can be disconnected from the power supply terminals and electrically connected to a reference potential so that interference signals cannot reach the components via the power supply lines.

Abstract: The invention relates to an arrangement for the protection of electronic functional units and/or functional groups from disturbance quantities. The invention is characterized in that a division of the functional units and/or groups into partial units and/or groups with different sensitivity to the disturbance quantities is provided, in that a different screening from the disturbance quantities is assigned to the partial units and/or groups with different sensitivity to the disturbance quantities, and in that at least two of the screenings complete each other to a screening with a greater efficiency degree or factor, respectively.

Abstract: In a power line noise filter, a detection circuit detecting variations in electric current in two conductive lines of an electric power line, thereby detecting common mode noise that causes a change in electric current in the power line. A phase-inverted signal generation circuit then generates a phase-inverted signal whose is inverted to that of the noise detected by the detection circuit. Further, an injection circuit causes a change in electric current corresponding to the phase-inverted signal, for the two conductive lines of the electric power line. The common mode noise causing a change in electric current in the electric power lines is thereby canceled.

Abstract: A circuit configuration with reduced EMC radiation in a motor vehicle includes a semiconductor switch with a load section which is connected, on one hand, through a first supply line to a positive battery terminal and, on the other hand, through a second supply line to a load and a freewheeling diode. A device for pulse-width modulation controls the semiconductor switch. The semiconductor switch and the freewheeling diode are disposed as close as possible to the battery terminal, so that supply leads from the battery to the semiconductor switch and the freewheeling diode are shortened.

Abstract: An Apparatus for extracting communications signals from power lines, which lines are arranged such that leakage of signals occurs between them. The apparatus receives a signal from each of at least two of lines (blue, red, yellow) and combines the received signals so as to increase the ratio of wanted signal to interference plus noise S/(1+N). Preferably the combining is achieved by weights WB, WR, WY and a summer. The weights phase shift and scale the received signals in amplitude. The apparatus can also be used for transmitting in the downstream direction.

Abstract: Disclosed herein is a printed circuit board comprising a ground layer and a signal layer in which the characteristic impedance of a specific source line is made to be not less than three times as large as the impedance at an upper limit frequency at which the electromagnetic wave radiation of a specific capacitor may occur. In this printed circuit board, variation of a power source voltage and unnecessary electromagnetic wave radiation can be suppressed.

Abstract: An isolator having a driver circuit which responsive to an input signal drives appropriate signals into one or more coils which are magnetically coupled to one or more corresponding MR or GMR elements whose resistance is variable in response to the magnetic field applied by the coil(s), and an output circuit that converts the resistance changes to an output signal corresponding to the input signal. A Faraday shield is interposed between the coil(s) and the MR or GMR elements. Common mode transients applied to the driver are capacitively coupled from the coil(s) into the Faraday shield and therethrough to ground, instead of into the MR elements. A second Faraday shield may be disposed in spaced relationship with the first Faraday shield and referenced to the potential of the MR elements for even greater common mode rejection. The entire structure may be formed monolithically as an integrated circuit on a single substrate, for low cost, small size, and low power consumption.

Abstract: To provide a method of pseudogrounding which is capable of protecting against EMI by pseudogrounding communication lines, etc. without necessity of expensive ferrite cores and increasing the number of steps and cost. A wiring which is connected to an LSI (43) on a package and is connected to an external wiring (47) via a connector (461), radio-frequency connected via a capacitance (451, 452) to ta housing (42) in which protection against EMI is achieved so that the radiated noise energy is not higher than EMI restricted value level. This enables said wiring to be pseudogrounded.

Abstract: A method and an apparatus reduce peak electro-magnetic (EM) emissions from power and ground planes in, for example, a printed circuit board (PCB) by phase shifting synchronous signal sources to distribute EM emissions over a frequency range and by canceling at least some EM emissions with an inverse signal. According to one aspect of the present invention, two signal sources provide periodic outputs having the same period. The output of one of the signal sources, however, is delayed with respect to the output of the other signal source. Each signal source is coupled to a signal trace. The propagation delay over the signal trace coupled to the delayed signal source is shorter than the propagation delay over the other signal trace by the amount of the delay between the respective output signals. According to another aspect of the present invention, a noise cancellation driver is coupled to a signal source, a power or ground plane of the signal source, and an inverse voltage plane.

Abstract: An isolator having a driver circuit which responsive to an input signal drives appropriate signals into one or more coils which are magnetically coupled to one or more corresponding MR or GMR elements whose resistance is variable in response to the magnetic field applied by the coil(s), and an output circuit that converts the resistance changes to an output signal corresponding to the input signal. A Faraday shield is interposed between the coil(s) and the MR or GMR elements. Common mode transients applied to the driver are capacitively coupled from the coil(s) into the Faraday shield and therethrough to ground, instead of into the MR elements. A second Faraday shield may be disposed in spaced relationship with the first Faraday shield and referenced to the potential of the MR elements for even greater common mode rejection. The entire structure may be formed monolithically as an integrated circuit on a single substrate, for low cost, small size, and low power consumption.

Abstract: A power line communications system has a power line having a plurality of conductors which carry communications signals. A set of communications signals are coupled to a set of the plurality of conductors, each signal being coupled to a respective one of the set of conductors and the phasor relationship of the set of communications signals is chosen such that radiation of communications signals from the power line is minimised. The phasor relationship may be achieved by phase shifting one or more of the signals. This method allows communications signals to be transmitted at higher power levels, thereby extending range of transmission, while minimizing radiation from the line.

Abstract: The arrangements essentially comprise an antenna element placed in the vicinity of a radiating conductor of the equipment in such a manner as to absorb the electromagnetic energy reaching it by coupling with the radiating conductor.

Abstract: An overhead line for electrical energy transmission includes at least one phase conductor which receives a phase current which has a phase and an amplitude. A compensation loop surrounds the at least one phase conductor. A compensation current which has a phase and an amplitude is fed into the compensation loop by a driving voltage. The phase and the amplitude of the compensation current is set with respect to the phase and the amplitude of the phase current flowing in the at least one phase conductor such that a magnetic flux produced by the compensation current counteracts a magnetic flux produced by the phase current. At least one additional loop surrounds the at least one phase conductor connected to the compensation loop. The driving voltage for the compensation current is produced in the compensation loop and in the at least one additional loop. The compensation loop and the at least one additional loop define the at least one phase conductor into at least two main sections.

Abstract: A ground voltage reduction device is connected between a neutral reference node and a ground node defined by two bypass capacitors of a blocking circuit. The ground voltage reduction device senses the voltage difference between the neutral reference node and the ground node and drives the ground node to reduce the voltage difference between a voltage of the ground node and a voltage of the neutral reference node.

Abstract: A circuit for providing protection from effects of electromagnetic interference (EMI) at input pins and internal nodes of an integrated circuit (IC) includes a regenerative comparator (Schmitt trigger) to perform triggering functions in response to input pulses applied to the input pin, resulting in hysteresis between high and low trigger voltages. The hysteresis extends durations of false pulses induced by presence of EMI at the input pin. A filter is coupled to the regenerative comparator, with a filter response time with a duration at least as great as the expected largest duration of EMI-induced false pulses including extended duration attributable to the hysteresis, for filtering out the EMI-induced false pulses. A pulse generator is coupled to the filter, for generating a pulse for application to the IC whenever a pulse applied to the input pin has a duration exceeding the duration of the filter time constant.

Abstract: Transfer between alternative electrical power sources for highly inductive loads, such as motors, is made using an open transition with the load connected to the new source only after the voltage on the load bus has fallen below a predetermined value, preferably a value which is about 30% or less of the nominal source voltage.

Abstract: A filter circuit for reducing electromagnetic interference in an ungrounded hree-phase delta electrical system. The filter circuit includes a low- pass filter associated with each power phase having one input and output terminal placing an inductor in series with a phase conductor from a power supply. Input and output capacitors connect to a second input and output terminals respectively. An inductor connects in common between the second input and second output terminals thereby to complete a loop that is isolated from ground. Voltage suppression circuits connect from each phase to ground on the input side of the filter.

Abstract: A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions.

Abstract: A signal shielding structure for a cable, such as an audio cable, employs 1) a shielding sheath which is electrically insulated from and encloses the signal-carrying conductors in the cable and 2) one or two discrete inductors electrically coupled between selected discrete points of termination on the shielding sheath and selected ground points to provide a d.c. signal path to ground and to inhibit ground termination of r.f. signals. The shielding sheath floats and is preferably everywhere electrically isolated from direct-wire connection with all grounds and all signal sources except for the connection through the inductor or inductors.

Abstract: In an electrical power system for a residential building, a multi-conductor cable supplies power to loads in the residential building from a power supply. A net current returning from loads to the power supply via alternative conductive paths different from the neutral conductor in the cable creates a magnetic field in the vicinity of and inside of the residential building. A net current control device, including a ferromagnetic core, is attached to the multi-conductor cable in order to increase the impedance of the alternate conductive paths to the net current and to increase the net current flowing along the neutral conductor. Various modifications of the net current control device are disclosed.

Abstract: A testing contactor is provided for testing small-size semiconductor devices with large currents at high frequencies. Each semiconductor device to be tested has a plurality of leads. The testing contactor includes a plurality of first electric contact elements. A first Kelvin contact for a lead is formed of a first electric contact element in contact with the lead. The testing contactor further includes a plurality of second electric contact elements and a plurality of electric connection elements. An electric connection element in contact with the lead effectively extends the lead. A second Kelvin contact is formed of a second electric contact element and an electric connection element, the second electric contact element in contact with the electric connection element and the electric connection element in contact with the lead.

Abstract: In a switching circuit for use in a mobile telephone device in controllably transmitting a speech signal to a radio transmission unit through an output terminal (312), a first switch (31) is controlled by a control signal which is supplied to a control terminal (32) with a high level and a low level of putting the first switch in a conductive and a non-conductive state when a second switch (36) is put in its off and on states. A capacitor (35) is connected between the control terminal and the output terminal in order to make the switching circuit have a low output impedance when the first switch is put in its off state.

Abstract: A signal conditioning circuit having an input stage that receives inputs from at least one pair of conductors and processes the input signal through an input filter and a buffer amplifier. Each input filter and buffer amplifier are powered by independent power sources whose power return reference potentials are independently determined by the potential of the corresponding input signal potential reference conductor. The outputs of the buffer amplifiers, the power return reference potentials, and the power return reference potential of the conditioning circuit output are all appropriately added or subtracted in an output stage. The output stage consists of an amplifier buffer having low output impedance which is powered by a separate independent power source whose power return reference potential is independently determined by the potential of the output signal reference conductor. The output of this circuit stage is connected to an output inductor circuit which in turn drives the output signal conductor.

Abstract: A smoothing device for a power supply is provided comprising a rectifier for rectifying an output of an alternating current power supply and at least a pair of electrolytic capacitors for smoothing an output of said rectifier. The pair of electrolytic capacitors have a non-polarized structure in which a pair of electrode foils each having an oxide film on a surface are wound into a roll with a separator containing an electrolyte interposed therebetween. A pair of electrodes are connected to each of said pair of electrode foils. At least one of the pair of electrodes has a mark for distinguishing them from each other. The pair of electrolytic capacitors are so connected that magnetic fluxes generated by said electrode foils are cancelled with each other.

Abstract: A method and apparatus for mitigation of magnetic fields from magnetic field sources operating at low frequencies, typically less than 100 KHZ, are provided. The method is based on placing magnetic bodies of proper shape, size and physical properties close to the source of the magnetic field to cancel or reduce the magnetic field at desired sites, located away from the source. The method is applicable to mitigating all sources of magnetic fields including those generated by electric power lines, transformers, various tools, electronic devices and appliances. The apparatus, an application of the method to electric power transmission lines, consists of body of magnetic material disposed adjacent to at least one conductor of a multi-line electric power transmission system.

Abstract: An electrostatic discharge noise suppression method and system is disclosed for electronic devices, particularly those connected to data buses. Electrostatic discharge protection is provided by breaking high-frequency ground loops by inserting common mode inductors where they can be most effective-in the DC power supplies themselves, in the DC power connections, or just behind the DC connector in the electronic devices. Saturation of the cores of the common mode inductors is prevented in a preferred way by equalizing supply and return currents in the common mode inductors and by preventing DC ground currents from flowing in a chassis between the power supply and the electronic device.

Abstract: A power supply device has its power supply conductor bars, in which a.c. currents caused by a.c. noises flow in the same direction, laid closely in parallel while retaining their insulation thereby to increase the total inductance so that the impedance increases without accompanied by an increase in the d.c. resistance of the power supply conductor bars. An increased coupling impedance of the power supply conductor bars effectively attenuates the a.c. noises from d.c. power units, which then supply d.c. power with reduced a.c. noises to an electronic apparatus such as a computer through the power supply device.

Abstract: A discharge working machine in which a working current is supplied from a power source to a working electrode and a workpiece by a core wire of a coaxial cable and a current flowing in the opposite direction to a current flowing through the core wire flows into a shield of the coaxial cable.

Abstract: An electric noise absorber, comprising divided magnetic substances made of ferrite, a holding member for holding the magnetic substances at its holding projections, and engaging members formed in the magnetic substances which engage with the holding projections. The electric noise absorber is attached to and detached from an electric cable easily without removing the electric cable and is composed of a minimum number of units.

Abstract: A circuit for providing a DC isolation between a pulse generator (E) and a load (CH) of the kind comprising a primary circuit (2), a secondary circuit (4) and at least one magnetization current elimination circuit (12) on the secondary side, characterized in that it is provided on the primary side with at least one unidirectional transmission circuit (15) which causes the pulses to pass and causes the magnetization current forcibly to be dissipated through the secondary in the circuit (12) for eliminating the said magnetization current and with at least one circuit (18) for attenuating the transient phenomena due to the commutation thus protecting the pulse generator (E).

Abstract: Electronic system grounding includes two system grounding paths for card caged electronic modules, with a first grounding path through the card cage and a second grounding path through the system power supply. The two system grounding paths are used to minimize noise and reduce unwanted induced superimposed transient voltage levels.

Abstract: Disclosed is an interface assembly for use in conjunction with a test contactor assembly for integrated circuit (IC) electronic devices and the like. The test contactor assembly has at least one row of flexible contacts that are each secured at a lower end to a base. A conductive plate is also secured to the base and extends in a generally parallel, closely spaced relationship to each row of contacts. The dimensions of the plate and its spacing from the associated contacts produce a distributed capacitance with respect to each contact in the row such that a fast-rising test signal launched in a contact encounters a generally "characteristic" or purely resistive impedance that is frequency independent. The interface assembly, which connects the test contactor assembly to a test circuit, has a contactor board secured to the base of the contactor assembly. A pattern of conductive stripes is carried on at least one face of the board.

Abstract: A test contactor assembly for integrated circuit (IC) electronic devices and the like has at least one row of flexible contacts that are each secured at a lower end to a base. A conductive plate is also secured to the base and extends in a generlly parallel, closely spaced relationship to each row of contacts. The dimensions of the plate and its spacing from the associated contacts produce a distributed capacitance with respect to each contact in the row such that a fast-rising test signal launched in a contact encounters a generally "characteristic" or purely resistive impedance that is frequency independent. A flexible insulating material is preferably located between the plate and its associated row of contacts to maintain the desired spacing as the plate and the contacts are flexed into electrical connection with associated pins of the device.

Abstract: The electromagnetic interference produced by arc discharge lamps and other devices operating at frequencies in excess of 15,000 Hz is reduced by providing a current path external to the envelope containing the discharge, the current flow in the path being oriented so as to produce a magnetic field generally in opposition to the magnetic field generated by the current in the arc discharge. The present invention is particularly applicable to circular fluorescent lamps with a centrally disposed ballast operating at relatively high frequencies.

Abstract: To connect two bus bars to two sets of cables which are bunched to produce a low stray field, a connecting piece is provided, in which parallel, electrically conducting, plates are provided with angled-off connecting straps and connecting lugs, the connecting straps being connected to the bus bars and the connecting lugs being connected to the cable ends by means of cable terminals.