Abstract: Continuous glucose monitoring (CGM) may include applying a periodic excitation signal via an electrode of a CGM sensor to human interstitial fluid to drive an oxidation/reduction reaction, and measuring the current through the electrode. In some embodiments, the measured current is sampled and digitized, and various harmonics of the excitation signal's fundamental frequency are extracted. A set of relationships of at least two harmonics each is generated from the spectral amplitudes of a set of pairs, triplets, etc., of the harmonics, and the set of relationships is mapped to a glucose concentration such as based on the contents of a harmonic relationship database having a pre-existing set of harmonic relationships and glucose concentrations to which those sets of harmonic relationships correspond, for example. Numerous other embodiments are provided.

Abstract: Continuous glucose monitoring (CGM) may include applying a periodic excitation signal via an electrode of a CGM sensor to human interstitial fluid to drive an oxidation/reduction reaction, and measuring the current through the electrode. In some embodiments, the measured current is sampled and digitized, and various harmonics of the excitation signal's fundamental frequency are extracted. A set of relationships of at least two harmonics each is generated from the spectral amplitudes of a set of pairs, triplets, etc., of the harmonics, and the set of relationships is mapped to a glucose concentration such as based on the contents of a harmonic relationship database having a pre-existing set of harmonic relationships and glucose concentrations to which those sets of harmonic relationships correspond, for example. Numerous other embodiments are provided.

Abstract: Continuous glucose monitoring (CGM) may include applying a periodic excitation signal via an electrode of a CGM sensor to human interstitial fluid to drive an oxidation/reduction reaction, and measuring the current through the electrode. In some embodiments, the measured current is sampled and digitized, and various harmonics of the excitation signal's fundamental frequency are extracted. A set of relationships of at least two harmonics each is generated from the spectral amplitudes of a set of pairs, triplets, etc., of the harmonics, and the set of relationships is mapped to a glucose concentration such as based on the contents of a harmonic relationship database having a pre-existing set of harmonic relationships and glucose concentrations to which those sets of harmonic relationships correspond, for example. Numerous other embodiments are provided.

Abstract: Continuous glucose monitoring (CGM) may include applying a periodic excitation signal via an electrode of a CGM sensor to human interstitial fluid to drive an oxidation/reduction reaction, and measuring the current through the electrode. In some embodiments, the measured current is sampled and digitized, and various harmonics of the excitation signal's fundamental frequency are extracted. A set of relationships of at least two harmonics each is generated from the spectral amplitudes of a set of pairs, triplets, etc., of the harmonics, and the set of relationships is mapped to a glucose concentration such as based on the contents of a harmonic relationship database having a pre-existing set of harmonic relationships and glucose concentrations to which those sets of harmonic relationships correspond, for example. Numerous other embodiments are provided.

Abstract: Continuous glucose monitoring (CGM) may include applying a periodic excitation signal via an electrode of a CGM sensor to human interstitial fluid to drive an oxidation/reduction reaction, and measuring the current through the electrode. In some embodiments, the measured current is sampled and digitized, and various harmonics of the excitation signal's fundamental frequency are extracted. A set of relationships of at least two harmonics each is generated from the spectral amplitudes of a set of pairs, triplets, etc., of the harmonics, and the set of relationships is mapped to a glucose concentration such as based on the contents of a harmonic relationship database having a pre-existing set of harmonic relationships and glucose concentrations to which those sets of harmonic relationships correspond, for example. Numerous other embodiments are provided.

Abstract: A power converter for heat tracing applications is disclosed. The power converter includes a controller configured to control an input switching stage. The power converter also includes an output filter, the output filter electrically coupled to the input switching stage. Further, the power converter includes a passive cooling element, the passive cooling element coupled to the power converter. The controller is configured to select a peak voltage and set a power converter output voltage based on at least one of the peak voltage and a power converter input voltage. The passive cooling element is configured to decrease a temperature of the power converter and to obviate the need for cooling with moving parts, making the system viable for hazardous areas in addition to non-hazardous areas. The input switching stage includes a plurality of transistors. The power converter output voltage and the power converter input voltage are both alternating current.

Abstract: A power converter for heat tracing applications is disclosed. The power converter includes a controller configured to control an input switching stage. The power converter also includes an output filter, the output filter electrically coupled to the input switching stage. Further, the power converter includes a passive cooling element, the passive cooling element coupled to the power converter. The controller is configured to select a peak voltage and set a power converter output voltage based on at least one of the peak voltage and a power converter input voltage. The passive cooling element is configured to decrease a temperature of the power converter and to obviate the need for cooling with moving parts, making the system viable for hazardous areas in addition to non-hazardous areas. The input switching stage includes a plurality of transistors. The power converter output voltage and the power converter input voltage are both alternating current.

Abstract: Embodiments of the invention provide systems and methods for tracking the thermal age of a self-regulating heating cable. Over a time period, current and voltage data for a cable signal are collected, from which spectral information is extracted. The spectral information has a frequency component and an amplitude component. The cable signal is processed to extract a line frequency signature that includes the electrical system's line current frequency and at least some of its harmonics. A ratio of the amplitudes of at least two of the odd harmonics of the line current frequency is calculated. The ratio is compared to an aging curve indicating the thermal age of the cable as a function of the odd-harmonic ratios. The curve may be obtained in a laboratory setting or in the field by characterizing a cable with zero hours of use. The characterizing may include aging the cable to determine the curve.

Abstract: Embodiments of the invention provide systems and methods for detecting a sustained arc in an electrical system containing polymer-based, semi-conducting components which derive their conductivity from carbon black, carbon nanotubes or other conductive materials. Over a time period, current and voltage data for a cable signal are collected, from which spectral information is extracted. The spectral information has a frequency component and an amplitude component. The cable signal is processed to remove a line frequency signature that includes the electrical system's line current frequency and its harmonics. One or more off-harmonic frequency bands are extracted from the cable signal and analyzed to determine the presence of an arc signature therein. Analysis of the off-harmonic frequency bands can include applying a matched filter to the off-harmonic frequency bands to obtain an indicator signal and determining if the indicator signal exceeds a threshold that indicates the presence of the sustained arc.

Abstract: Embodiments of the invention provide systems and methods for detecting a sustained arc in an electrical system. Over a time period, current and voltage data for a load signal are collected, from which spectral information is extracted. The spectral information has a frequency component and an amplitude component. The load signal is processed to remove a line frequency signature from the spectral information. One or more sub-harmonic frequency bands are extracted from the load signal and analyzed to determine the presence of an arc signature therein. The sub-harmonic frequency bands may be centered on frequencies corresponding to an integer number of half line cycle periods. Analysis of the sub-harmonic frequency bands can include detecting the peak amplitudes of the rectified sub-harmonic frequency bands to obtain an indicator signal and determining if the indicator signal exceeds a threshold that indicates the presence of the sustained arc.

Abstract: Embodiments of the invention provide a snow and ice melting heating system that can include a capacitive probe, such as an aerial probe, having a capacitive sensor to improve detection of the onset or accumulation of snow or ice. The capacitive probe provides uniform response to the presence of snow and ice on the capacitive sensor, and the capacitive sensor can be protected from galvanic corrosion by one or more coatings without affecting the detection of snow or ice. The capacitive probe can indicate when heaters should be turned on to melt snow or ice. The system can include a light probe having a color sensor to detect snow cover, or lack thereof, on a monitored surface from the color of reflected light. The light probe provides a monitoring device that can detect when the snow cover has melted and signal for the system heaters to be turned off.

Abstract: Embodiments of the invention provide systems and methods for tracking the thermal age of a self-regulating heating cable. Over a time period, current and voltage data for a cable signal are collected, from which spectral information is extracted. The spectral information has a frequency component and an amplitude component. The cable signal is processed to extract a line frequency signature that includes the electrical system's line current frequency and at least some of its harmonics. A ratio of the amplitudes of at least two of the odd harmonics of the line current frequency is calculated. The ratio is compared to an aging curve indicating the thermal age of the cable as a function of the odd-harmonic ratios. The curve may be obtained in a laboratory setting or in the field by characterizing a cable with zero hours of use. The characterizing may include aging the cable to determine the curve.

Abstract: Embodiments of the invention provide systems and methods for detecting a sustained arc in an electrical system. Over a time period, current and voltage data for a load signal are collected, from which spectral information is extracted. The spectral information has a frequency component and an amplitude component. The load signal is processed to remove a line frequency signature from the spectral information. One or more sub-harmonic frequency bands are extracted from the load signal and analyzed to determine the presence of an arc signature therein. The sub-harmonic frequency bands may be centered on frequencies corresponding to an integer number of half line cycle periods. Analysis of the sub-harmonic frequency bands can include detecting the peak amplitudes of the rectified sub-harmonic frequency bands to obtain an indicator signal and determining if the indicator signal exceeds a threshold that indicates the presence of the sustained arc.

Abstract: Embodiments of the invention provide systems and methods for detecting a sustained arc in an electrical system containing polymer-based, semi-conducting components which derive their conductivity from carbon black, carbon nanotubes or other conductive materials. Over a time period, current and voltage data for a cable signal are collected, from which spectral information is extracted. The spectral information has a frequency component and an amplitude component. The cable signal is processed to remove a line frequency signature that includes the electrical system's line current frequency and its harmonics. One or more off-harmonic frequency bands are extracted from the cable signal and analyzed to determine the presence of an arc signature therein. Analysis of the off-harmonic frequency bands can include applying a matched filter to the off-harmonic frequency bands to obtain an indicator signal and determining if the indicator signal exceeds a threshold that indicates the presence of the sustained arc.