Abstract: Systems and methods are provided for monitoring the effects of conductive dust deposits that compromise the ability of a trip unit to accurately detect AC current in a circuit interrupter. When a Rogowski coil is used as a current sensor in the circuit interrupter and the trip unit processes the output of the Rogowski coil using a printed circuit board assembly (PCBA) processing circuit, the DC component of the processing circuit output signal can be analyzed to determine whether any conductive dust has formed unintended electrical pathways on the PCBA and compromised the ability of the PCBA to accurately measure AC current in the circuit interrupter. It can be determined that such unintended electrical pathways have formed when the DC component of the processing circuit output either exceeds a predetermined threshold or has increased by a significant amount after opening of the separable contacts.

Abstract: Systems and methods for identifying and presenting prior findings data in a radiology review workflow, based on natural language processing (NLP) of unstructured radiology report text, are disclosed. In an example, prior findings are generated with operations including: receiving text from a prior radiology report prepared for a patient in a prior radiology study; processing the text with a trained NLP engine to classify discrete prior findings in the prior radiology study that identify observed condition(s) and characteristics of the observed condition(s); and outputting or presenting the prior findings, such as in a radiology review user interface. In an example, the radiology review user interface displays the observed condition(s) and the characteristic(s) of the observed condition(s) to a user (e.g., a radiologist), and can apply sorting, filtering, or grouping based on pathology phrases or attribute words associated with the observed conditions or the characteristics of such observed conditions.

Abstract: In a circuit breaker arrangement, this disclosure describes a method and circuit design enables a current transformer to be used to detect ground faults in circuit breakers (such as a main-tie-main circuit breakers) that have been designed to receive signals from Rogowski coils.

Abstract: A circuit interrupter including a busbar, a Rogowski coil disposed around the busbar and structured to sense current having a first frequency flowing through the busbar, a test injector circuit structured to input a test signal having a second frequency to the Rogowski coil, high or band pass filter circuitry structured to receive an output of the Rogowski coil, the output including a first component having the first frequency and being proportional to the current through the busbar and a second component having the second frequency and being proportional to a temperature of the Rogowski coil, and to attenuate the first component of the Rogowski coil output, and an electronic trip unit including a temperature measurement unit structured to receive an output of the high or band pass filter circuitry and to estimate the temperature of the busbar based on the output of the high or band pass filter circuitry.

Abstract: A data connection apparatus of a supporting apparatus includes a stationary part and a movable part. One of the stationary and movable parts has a circuit board having a number of electrically conductive pads, and the other has a receptacle within which the circuit board is received, such as when a circuit interrupter is moved to an installed position within a cassette of a draw-out switchgear cabinet. The data connection apparatus includes a housing within which the receptacle is formed, with the housing having a plurality of electrical contacts within the receptacle. The housing and the circuit board each have relieved regions in the exemplary form of ramped surfaces and edges that facilitate reception of the circuit board in the receptacle. Moreover, the circuit board and the housing are situated on structured that afford a certain level of flexibility to further facilitate reception of the circuit board in the receptacle.

Abstract: A data connection apparatus of a supporting apparatus includes a stationary part and a movable part. One of the stationary and movable parts has a circuit board having a number of electrically conductive pads, and the other has a receptacle within which the circuit board is received, such as when a circuit interrupter is moved to an installed position within a cassette of a draw-out switchgear cabinet. The data connection apparatus includes a housing within which the receptacle is formed, with the housing having a plurality of electrical contacts within the receptacle. The housing and the circuit board each have relieved regions in the exemplary form of ramped surfaces and edges that facilitate reception of the circuit board in the receptacle. Moreover, the circuit board and the housing are situated on structured that afford a certain level of flexibility to further facilitate reception of the circuit board in the receptacle.

Abstract: In a circuit breaker arrangement, this disclosure describes a method and circuit design enables a current transformer to be used to detect ground faults in circuit breakers (such as a main-tie-main circuit breakers) that have been designed to receive signals from Rogowski coils.

Abstract: A circuit interrupter including a busbar, a Rogowski coil disposed around the busbar and structured to sense current having a first frequency flowing through the busbar, a test injector circuit structured to input a test signal having a second frequency to the Rogowski coil, high or band pass filter circuitry structured to receive an output of the Rogowski coil, the output including a first component having the first frequency and being proportional to the current through the busbar and a second component having the second frequency and being proportional to a temperature of the Rogowski coil, and to attenuate the first component of the Rogowski coil output, and an electronic trip unit including a temperature measurement unit structured to receive an output of the high or band pass filter circuitry and to estimate the temperature of the busbar based on the output of the high or band pass filter circuitry.

Abstract: A circuit for receiving the output from one of either a current transformer or a di/dt sensor includes: an input pair having a first input and a second input; a first output; a second output; a current transformer input circuit connected between the first input and the second input; and a di/dt sensor input circuit connected between the first input and the second input. The current transformer input circuit is configured to receive output from a current transformer connected to the input pair and to output a signal representative of the current sensed thereby via the first output. The di/dt sensor input circuit is configured to receive output from a di/dt sensor connected to the input pair and to output a signal representative of the current or time rate of change of the current sensed thereby via the second output.

Abstract: A molded case circuit interrupter advantageously employs a circuitry component that is situated adjacent a rear exterior surface of the molded case of the molded case circuit interrupter. Previous circuit interrupters have sometimes employed a non-conductive backsheet of a nominal thickness of 0.062 inches that was adhered to the rear surface of the molded case circuit interrupter in order to electrically isolate screws, posts, and the like that were mounted to and that were exposed on the rear portion of a molded case thereof. The disclosed and claimed concept provides a circuitry component in place of or in addition to the back sheet, with the circuitry component including flexible ribbons having electrical conductors that extend through holes formed in the molded case and that are electrically connected with electronic components that are situated within the interior of the molded case.

Abstract: A circuit for receiving the output from one of either a current transformer or a di/dt sensor includes: an input pair having a first input and a second input; a first output; a second output; a current transformer input circuit connected between the first input and the second input; and a di/dt sensor input circuit connected between the first input and the second input. The current transformer input circuit is configured to receive output from a current transformer connected to the input pair and to output a signal representative of the current sensed thereby via the first output. The di/dt sensor input circuit is configured to receive output from a di/dt sensor connected to the input pair and to output a signal representative of the current or time rate of change of the current sensed thereby via the second output.

Abstract: A circuit interrupter includes a sensor structured to output a sensor signal, a control unit structured to receive an external control signal, the control unit including: a communication interface structured to receive the external control signal, and a waveform generator structured to generate a waveform equivalent to the sensor signal in response to the external control, and a signal processing circuit structured to receive and process the sensor signal or the generated waveform and to output the processed sensor signal or generated waveform to the control unit.

Abstract: A molded case circuit interrupter advantageously employs a circuitry component that is situated adjacent a rear exterior surface of the molded case of the molded case circuit interrupter. Previous circuit interrupters have sometimes employed a non-conductive backsheet of a nominal thickness of 0.062 inches that was adhered to the rear surface of the molded case circuit interrupter in order to electrically isolate screws, posts, and the like that were mounted to and that were exposed on the rear portion of a molded case thereof. The disclosed and claimed concept provides a circuitry component in place of or in addition to the back sheet, with the circuitry component including flexible ribbons having electrical conductors that extend through holes formed in the molded case and that are electrically connected with electronic components that are situated within the interior of the molded case.

Abstract: A current sensing circuit for use with a Rogowski coil arranged around a conductor having a primary current includes input terminals structured to receive an output voltage of the Rogowski coil, an analog to digital converter structured to convert a differential voltage to a digital differential voltage signal, a digital integrator structured to receive the digital differential voltage signal, to implement a discrete-time transfer function that is a transform of a transfer function of an analog integrator, and to output a digital integrator output signal, and a direct current blocker filter structured to remove a direct current bias from the digital integrator output signal and to output a digital current output signal that is proportional to the primary current in the conductor.

Abstract: A circuit interrupter includes an electronic trip unit structured to receive power from a power supply. The electronic trip unit includes a start-up process and is structured to proceed through the start-up process when the electronic trip unit begins receiving power from the power supply and a timing circuit including a capacitor structured to begin charging when the electronic trip unit begins receiving power from the power supply. The electronic trip unit includes a processor that is structured to read a voltage across the capacitor when the start-up process has completed and to determine an elapsed time of the start-up process based on the read voltage across the capacitor.

Abstract: A direct current arc fault detector includes a first current sensor sensing an alternating current component of current flowing in a DC power circuit; a second current sensor sensing a DC component of the current; and a bandpass filter filtering the sensed AC component. A demodulating logarithmic amplifier includes an input of the filtered AC component, and an output. An integrator or minimum detector includes an input connected to the amplifier output, and an output. A processor repetitively inputs and then resets the integrator or minimum detector output, and determines an arc when, for a predetermined time: the sensed DC component being greater than a first predetermined value, and a present value of the integrator or minimum detector output being greater than or different from a previous value of such output by more than a second predetermined value, or the present value being greater than a third predetermined value.

Abstract: A security tag and electronic system detect unauthorized tampering of Molded Case Circuit Breakers (MCCBs) and authenticate MCCBs against counterfeiting or gray market items. The system can involve digital generation of a public key and a corresponding private key, both keys comprise large positive integers, applying the private key to an MCCB-specific message string and creating a digital signature code, generating an identification code from the MCCB-specific message string and the digital signature code, building the identification code into one or more security tags, and installing the security tags on MCCBs, and authenticating MCCBs through a verification step and a certification step. The verification step reads the security tags, and verifies the identification code. The certification step checks the identification code against a revocation list that contains previously compromised identification codes.

Abstract: A circuit interrupter includes an electronic trip unit structured to receive power from a power supply. The electronic trip unit includes a start-up process and is structured to proceed through the start-up process when the electronic trip unit begins receiving power from the power supply and a timing circuit including a capacitor structured to begin charging when the electronic trip unit begins receiving power from the power supply. The electronic trip unit includes a processor that is structured to read a voltage across the capacitor when the start-up process has completed and to determine an elapsed time of the start-up process based on the read voltage across the capacitor.

Abstract: An electrical switching apparatus includes a transductor circuit that senses a direct current between an input terminal and an output terminal and outputs an alternating current proportional to the direct current. The electrical switching apparatus also includes a current sensor configured to sense an alternating current component of the direct current. The electrical switching apparatus further includes an alternating current electronic trip circuit including an arc fault detection circuit configured to detect an arc fault based on the sensed alternating current component. The alternating current electronic trip circuit is also configured to control pairs of separable contacts to trip open based on the alternating current output from the transductor circuit or the detected arc fault. The electrical switching apparatus also includes a power supply structured to provide direct current power to the alternating current electronic trip circuit.

Abstract: A current sensing circuit for use with a Rogowski coil arranged around a conductor having a primary current includes input terminals structured to receive an output voltage of the Rogowski coil, an analog to digital converter structured to convert a differential voltage to a digital differential voltage signal, a digital integrator structured to receive the digital differential voltage signal, to implement a discrete-time transfer function that is a transform of a transfer function of an analog integrator, and to output a digital integrator output signal, and a direct current blocker filter structured to remove a direct current bias from the digital integrator output signal and to output a digital current output signal that is proportional to the primary current in the conductor.