Abstract: In this invention, a new whole-chip ESD protection scheme with the ESD buses has been proposed to solve the ESD protection issue of the CMOS IC having a large number of separated power lines. Multiple ESD buses, which are formed by the wide metal lines, have been added into the CMOS IC having a large number of separated power lines. The bi-directional ESD-connection cells are connected between the separated power lines and the ESD buses, but not between the separated power lines. The ESD current on the CMOS IC with more separated power lines are all conducted into the ESD buses, therefore the ESD current can be conducted by the ESD buses away from the internal circuits and quickly discharged through the designed ESD protection devices to ground. By using this new whole-chip ESD protection scheme with the ESD buses, the CMOS IC having more separated power lines can be still safely protected against ESD damages.

Abstract: A device for protecting a braking resistor for locomotives supplied with AC power obtained by chopping the DC voltage from the power grid comprising at least one pack of resistive components of the resistor which has at least one reference resistive component which is made of a different material than the other resistive components of the pack but is suitable to react thermally in the same manner as the other resistive components of the pack when it is crossed by the same current, and a control circuit which is associated with the pack of resistive components and is suitable to detect their temperature by detecting the variations in the electrical characteristics of the reference resistive component.

Abstract: An arcing fault protection system for a switchgear enclosure includes a switching device for rapidly diverting current from the source bus of an electrical distribution system in response to the detection of arcing faults in the system. The switching device, which may comprise a mechanical switch, a solid-state switch or hybrid device, quickly diverts current carried on the source bus to effectively extinguish arcing fault currents present in the distribution system, preventing the generation of gases at high pressures and/or temperatures so as to protect the switchgear equipment from damage.

Abstract: Short-circuits are liable to occur between the two conductors in a system in which data and/or energy is transmitted to a plurality of receivers/users via two conductors. Transmission is then interrupted and the supply source is inadmissibly over-loaded. The invention provides disconnecting units which recognize occurrence of short-circuits between the conductors and, in response thereto, isolate the part of the system in which the short-circuit has occurred from the supply of data and/or energy, so that the remainder of the system remains operational. After removal of the short-circuit, the isolated part is automatically re-connected to the system. The potential on the conductors ahead of and following a disconnecting unit is monitored via current limiting circuit elements which bridge a switch in the disconnecting unit.

Abstract: A protective relay receives current and voltage inputs, digitizes them and reduces the effects of high and low frequency noise. In the case of a distance relay, incorporated in the relay is a signal generator which generates "operate" and "restraint" sinusoidal signals. In the case of a current or voltage relay, operate is a digitized version of current (voltage) and restraint is a pre-specified constant. In all cases, a magnitude comparator, implemented using short (two sample) data window algorithms, compares the magnitude of the operate and restraint signals and outputs a trip condition signal. The trip condition output is limited to a finite number of values by a limiter system and sent to an adaptive trip counter system. The adaptive trip counter system employs trip counter processing, which determines whether a trip signal will be initiated, immediately or after a period of delay.

Abstract: The system and method of the present invention facilitate clamping of a land grid array integrated circuit (LGA IC) device through adjustment and calibration of the clamping system in relation to the connector/socket features used for a given type of LGA IC device and connector/socket. In order to accommodate for different connector/socket heights, the clamping system of the present invention includes exchangeable calibrated springs and an exchangeable shim that enable the clamping system to adjust to a specific connector/socket height. Due to the level of calibration, the system and method provides controlled downward vertical force at the level of force required to clamp the pads of the LGA IC device to the contacts of the connector/socket thereby providing complete electric contact therebetween and complete electric contact between the connector/socket and a circuit board.

Abstract: An overload protection circuit for a power switch has a delay element by means of which the voltage which is dropped across the power switch, the supply voltage and a temperature margin are evaluated in comparison with a maximum permissible depletion layer temperature. In the practical embodiment, a capacitor is provided which is charged and discharged by suitably controlled current sources. A disconnect signal for switching the power switch is produced by comparing the capacitor voltage with the temperature margin. The circuit ensures a safe disconnection in the event of a short condition in the load, even in the case of a periodic switching operation of the power switch.

Abstract: A subscriber line interface circuit ("SLIC") for a telecommunications device powered from a single power source and using a voltage regulator to limit the voltage across the terminals of the telecommunications device to a predetermined value below the industry standard voltage limits. The SLIC selectively enables or disables the speech amplifiers responsive to an external control signal that is independent of the on-hook/off- hook status of the telecommunications device. The SLIC provides a ringing signal and/or a caller identification signal through the speech amplifiers to the telecommunications device while the telecommunications device is on-hook.

Abstract: A radio frequency isolation system for geographically distance signal sources comprising AC and DC signals which develop differences in ground potential includes a control cabinetry chassis with the DC input signal source being electrically grounded to the chassis at the input side of the cabinetry and a hybrid circuit connected to the chassis through capacitors with the AC input signal being connected to the hybrid circuit for grounding the signal at both the input and output ends of the hybrid circuit to the chassis.

Abstract: A compact, low-cost outage management emergency power supply device with a simple constitution is provided by connecting an auxiliary capacitor and charging battery to a DC link portion. In one embodiment, an auxiliary capacitor is connected in series via a switching circuit to a DC link portion which supplies direct-current voltage of a converter device which converts alternating-current voltage to direct-current voltage, and the input-output of current to the auxiliary capacitor is controlled by the switching circuit, so that the capacity of the additional auxiliary capacitor is not subject to limitations. Further, in another embodiment, a charging battery is connected to a DC link portion via a parallel circuit of a switching circuit or diode, and a resistor.

Abstract: For an electronic device having at least one power switch for each of two or more power sources such that the power switches can be selectively activated or deactivated depending on a signal supplied to them, a protection circuit having a current-sense circuit coupled to measure the current from the two or more power sources, and a latch for producing a switch deactivating signal and applying it to the switches in response to an over-current signal from the current-sense circuit can protect the switches and the electronic device from soft-short circuits and absolute short circuits. Bypass resistors coupled to the switches allow the electronic device to receive a small current ("pre-charge") before any of the switches are activated so that a comparator can test for the presence of various types of short circuits. Additionally, the precharging brings the electronic device to a higher voltage (as compared to no pre-charging) when one of the switches is activated, thereby helping to reduce in-rush currents.

Abstract: A method and apparatus for testing an integrated circuit die including a probe card (10) having a plurality of surface mount pads (45) arranged in a pattern (50) substantially corresponding to an area array pattern of die bumps (25) on the IC die. The pads and the die bumps are respectively electrically connected to each other with conductive probes (30). A plurality of test contacts (55) located around the periphery of the probe card (10) are in electrical contact to each surface mount pad (45) with electrical traces (65). An integrated circuit tester (60) having a plurality of test channels is electrically connected to a selected test contact (55) of the probe card (10), thereby forming a continuous conductive path between the integrated circuit tester (60) and the die bumps (25) on the IC die.

Abstract: A tester for power transformers and capacitors includes a pulse generator for applying a pulsating test signal to a pair of test leads which may be connected across the terminals of the device to be tested. Also connected across the test leads are a capacitor detector, an inductor detector and a continuity detector. If the connections to the transformer or capacitor in the device to be tested are good, the capacitor detector and inductor detector will distinguish one from the other and indicate that its condition is good. If the connections to the device are not good, the continuity detector will indicate whether there is a short circuit or open circuit condition. The detectors are coupled through control logic circuitry to an indicator circuit including a horn and blinking lights for providing unique indications of capacitor okay, inductor okay, short and open conditions. The capacitor detector provides a discharge path for a capacitor and detects the discharge current flow.

Abstract: A system and method for measuring phase-angle in electrical power systems includes inputting a reference signal into a receiving terminal of a communication system at a reference station and then sending the reference signal through the communication system. The reference signal is received at a substation and shaped as a quasi-reference signal. A phase difference .beta. between the quasi-reference signal and a tested signal at the substation is then measured. Phase delay of the reference signal caused by the communication system, including phase delay produced from sending means, receiving means, relaying units, and communication channels, is calculated. A phase difference .alpha. is then calculated between the reference signal and the tested signal according to the phase difference .beta. between the quasi-reference signal and the tested signal and the phase delay of the reference signal caused by the communication system.

Abstract: An inductive proximity switch includes a coil that is supplied with periodic transmitting current pulses. Signals which correspond to voltages induced in the coil after the end of a transmitting current pulse by the decaying current which previously flows in the detected body due to the voltage induced therein by the transmitting current pulse are then processed. The coil is supplied with transmitting current pulses whose direction alternates periodically. The current flow pattern is such that in the first half of a period of the current supplied to the coil, the transmitting current delivered to the coil flows in a first direction and substantially only during a first interval which is shorter than one half of the period of the transmitted pulses. The transmitted current subsequently decays during a time interval and is negligibly small during the remaining time of the first half of the period.

Abstract: Provided is a protection circuit for high speed signal communication via a two-wire connection between the two output terminals of a PECL driver and the two input terminals of a PECL receiver. The PECL driver and receiver are supplied with power from individual power supplies. The protection circuit includes two diodes connected in series with a respective wire with their cathodes electrically coupled to the respective output terminal of the PECL driver and their anodes electrically coupled to the respective input terminal of the PECL receiver, and two resistors connected between the PECL receiver power supply and the anodes of the respective diode. The resistance of the resistors ensures forward biasing of the diodes when the receiver power supply is supplying power. A capacitor may be connected in parallel with the respective diodes.

Abstract: The electrical switchgear apparatus comprises a fixed part (1) and a removable part (2) designed to be connected to the fixed part to be connected to a power distribution system (4) and to a communication network (6). The removable part (2) comprises a communication circuit (23) and a first addressing device (24) connected to a first address input of the communication circuit (23). The fixed part (1) comprises a second addressing device (18) designed to be connected to a second addressing input of the communication circuit (23). To communicate, the communication circuit chooses in priority the address supplied by the second addressing device. If this address is not valid, it then chooses the address supplied by the first addressing device.

Abstract: Disclosed is an improved probe housing mechanism that will allow for the quick release of a probe tip from a testing tool. The invention includes a probe housing, a double cantilevered beam for holding a probe tip, and a releasable spring mechanism for holding the beam into place. The spring mechanism can be released by squeezing the spring together or by releasing a non-removable locking screw, thereby allowing the beam to be slidably removed from the probe housing for easy replacement.

Abstract: A semiconductor integrated circuit device includes a first protection circuit for protecting against static charge applied to a signal terminal, a second protection circuit for protecting against static charge applied between a power supply terminal and a ground terminal, and a main circuit protected from the static charge by the first and second protection circuits. The second protection circuit discharges the static charge through a break-down of p-n junctions of the component transistors or punch-through. The main circuit has a field effect transistor having a gate insulating layer, to which is applied the potential difference between the power supply line and the ground line, and having a break-down voltage higher than the break-down voltage of the p-n junction or the punch-through voltage of the second protection circuit, whereby the second protection circuit is effective against the static charge.

Abstract: A method and apparatus detects leakage current on a two wire power line and, in particular, provides a way to prevent hazardous electrical shocks to personnel on ECP equipped railroad trains. Two resistors of equal value are respectively connected in series to the two wires of the power line. A sensing resistor is connected in series with a junction of first two resistors, and a low voltage power source is connected between the sensing resistor and earth ground. A sensor is connected across the sensing resistor to detect a leakage current. The sensor is capable of detecting either positive or negative leakage currents. An output of the sensor is supplied to a controller which controls a high voltage power source connected across the two wires of the power line to be either in an OFF state or enabled to be in an ON state, depending on whether a leakage current is sensed by the sensor.