Abstract: An arc-fault detecting circuit-breaker system is used in conjunction with a protected electrical circuit whose current flow is to be interrupted upon the occurrence of an overcurrent fault or an arc fault. The arc-fault detecting circuit breaker system includes a normally closed circuit breaker, an arc-fault detector of the occurrence of an arc fault in the protected electrical circuit, and a circuit-breaker activating element operable responsive to the detector. The circuit-breaker activating element opens the circuit breaker in the event that the detector detects an arc fault in the protected electrical circuit. A status indicator structure, preferably in the form of a two-part pop-up button, has a first status indicator element which indicates the opening of the circuit breaker due to the overcurrent fault, and a second status indicator element which indicates the opening of the circuit breaker due to the arc fault.

Abstract: A protection system for an electrical power line system of the type comprising radially connected power line sections, wherein a first electrically upstream one of the line sections is connectable to a power source. The protection system comprises at least one relay installed at or near at least the upstream end of each line section to protect that line section, each relay having an associated circuit breaker. The relays are provided with a first set of accelerated overcurrent functions and a second set of under-current/under-voltage functions, the relays being directional and the first and second sets of functions being time graded in reverse to each other.

Abstract: A microcontroller-based system to detect ground-fault and grounded-neutral conditions in a monitored circuit of an electrical distribution system having line and neutral conductors. The system includes a single sensor producing an output signal responsive to current flow in both the line and neutral conductors of the monitored circuit, and a microcontroller receiving the sensor output signal and initiating the generation of a circuit status signal indicating one of a normal operating condition, a ground-fault condition or a grounded-neutral condition in the monitored circuit. The microcontroller is programmed to continuously test for ground-fault conditions by evaluating the sensor output signal and, at selected intervals, test for grounded-neutral conditions by evaluating the sensor's output signal response to a microcontroller initiated ping in the sensor circuit.

Abstract: A static discharging system includes a post having a lower end and an upper end. The lower end is selectively mounted in a ground surface adjacent to a gas pumping station such that the post extends upwardly from the ground surface. An electrically conductive plate is attached to the upper end of the post. An electrical conduit has first end electrically coupled to the plate and a second end extending into the ground surface.

Abstract: An electronic fuse comprising an integrated circuit having a control output terminal coupled to a control electrode of a power semiconductor switching device, the power semiconductor switching device being coupled in series with a load between first and second potentials, the integrated circuit further comprising a current sense input for sensing the current through the power semiconductor switching device, the integrated circuit further comprising a driver circuit for driving the power semi-conductor switching device, the driver circuit being coupled to a current limiting circuit responsive to the sensed current in the power semiconductor switching device, the current limiting circuit controlling the driver circuit whereby if the current through the power semiconductor switching device exceeds a predetermined threshold, the current limiting circuit generates a command to pulse the power semiconductor switching device on and off in a period of pulsed operation to maintain the current in the power semiconducto

Abstract: A current trip point detection circuit includes a transistor, a series of resistors, an amplifier, a comparator, and a series of switching circuits. The first transistor and the resistors are configured as an inverting gain stage. The amplifier cooperates with the first transistor to operate in a negative feedback arrangement. The gain in the feedback loop is adjusted by selective activation of additional transistors, where each additional transistor lowers the overall loop gain. The comparator is selectively coupled to a tap point in a voltage divider that is formed by resistors. The voltage divider tap point is selected to set a threshold for detection. The trip point is detected by the comparator, and may be adjusted between high and low trip points through the various configurations of the gain and voltage divider tap points via the switching circuits.

Abstract: A static electricity eliminating apparatus comprising; (A) a first electrically conductive piece and a second electrically conductive piece which are disposed so as to face each other through an insulating layer, and (B) a discharge means having one end electrically connected to the first electrically conductive piece and other end electrically connected to the second electrically conductive piece, wherein a charge electrostatically induced in the first electrically conductive piece and the second electrically conductive piece due to a contact of a static-electricity-charged object with the first electrically conductive piece is accumulated between the first electrically conductive piece and the second electrically conductive piece by dielectric polarization, and then, the charge is discharged with the discharge means in a state where the first electrically conductive piece and the second electrically conductive piece are not grounded.

Abstract: An input/output buffer protection circuit, which comprises an I/O pad, an I/O buffer, an n-well control circuit, a gate control circuit, and a protection component. The I/O buffer includes a PMOS transistor and a NMOS transistor. The n-well control circuit is coupled to an n-well of the PMOS transistor. When an input voltage higher than a source voltage is applied, voltage at the n-well of the PMOS is increased by the n-well control circuit to the input voltage level. The gate control circuit is coupled to the gate terminal of the PMOS transistor and the input/output pad. When an input voltage higher than a source voltage is applied, voltage at the gate terminal of the PMOS is increased by the gate control circuit to the source voltage level. Wherein the gate control circuit comprises a transistor and the transistor transfers a high potential control voltage to the gate of the PMOS transistor in output mode.

Abstract: In one embodiment, an integrated differential isolation loss detector is disclosed that generates a first temperature that is a function of a high side current and a second temperature that is a function of a low side current. A temperature sensor senses the difference between the first and second temperatures and provides an output signal that is indicative of the magnitude and the polarity of the sensed difference. A controller receives the output signal and if the difference is greater than a predetermined magnitude the high side current, the low side current, or both can be disconnected from the load. In another embodiment, an integrated differential isolation loss detector is disclosed that includes a first temperature difference generator that generates first and second temperatures where the difference between the first and second temperatures is a function of the magnitude of the high side current.

Abstract: A method and apparatus for a protection device for indicating when ground fault protection is not being provided by the protection device. The protection device includes source and load terminals between a conductive path and face terminals. The protection device further includes a latching mechanism, adapted to be operable between a first state in which the latching mechanism permits electrical contact between the source terminals and the load terminals and a second state in which the contact is broken; an alarm indicator, adapted to provide an indication that the protection device is not providing ground fault protection; and a fuse, adapted to blow when the latching mechanism fails to open during a manual test of the protection device.