Sm-based perovskite-type oxide (SmMeO3: Me = Cr, Mn, Fe, Co) thin-films could be synthesized by a wet-chemical method using an acetylacetone—Poly(Vinyl Pyrrolidone) (PVP) polymeric precursor method at 750℃. The pero...Sm-based perovskite-type oxide (SmMeO3: Me = Cr, Mn, Fe, Co) thin-films could be synthesized by a wet-chemical method using an acetylacetone—Poly(Vinyl Pyrrolidone) (PVP) polymeric precursor method at 750℃. The perovskite-type oxide thin-films were tried to apply an acetylene gas sensor based on AC impedance spectroscopy. Among the oxides tested, SmFeO3 thin-film sensor showed good sensor responses in which the AC impedance at 20 kHz was depending on acetylene gas concentration between 2 ppm and 80 ppm at 400℃.展开更多
The design and performances of a high dynamic range DC-AC current sensor utilizing Giant Magneto-Impedance (GMI) are presented. The sensor is based on a GMI element with negative feedback. The sensing element is a 30 ...The design and performances of a high dynamic range DC-AC current sensor utilizing Giant Magneto-Impedance (GMI) are presented. The sensor is based on a GMI element with negative feedback. The sensing element is a 30 μm diameter GMI Co-based amorphous wire. It is curled to a toroidal core of 2 cm diameter. A bias magnetic field of about 650 A/m is applied to the GMI element to obtain an asymmetric GMI effect. A strong negative feedback is introduced to ensure linearity in a wide dynamic range. Analog conditioning electronics was fully developed. This includes a square wave oscillator based on an inverter trigger;a peak detector and a high gain amplifier with zero adjust. The GMI element is driven at a 3 MHz frequency and 5 mA peak-to-peak current. The closed-loop operations are investigated and the performances of the sensor are presented. DC current measurements are performed. The sensor exhibits good sensitivity and very good linearity, free from hysteresis, in a wide dynamic range of ±40 A. The sensitivity is about 0.24 V/A and the linearity error is about 0.02% of the full scale (FS). The hysteresis error is smaller than the measurement accuracy. AC current measurements using the developed sensor have also been successfully achieved. The sensor bandwidth in closed-loop was about 1.7 kHz.展开更多
Energy demand will continue to rise as a result of predicted population growth. In this work, a user-friendly home energy monitoring system based on IoT is described, which is capable of collecting, analyzing, and dis...Energy demand will continue to rise as a result of predicted population growth. In this work, a user-friendly home energy monitoring system based on IoT is described, which is capable of collecting, analyzing, and displaying data. Users register their sensors and devices on the monitoring platform. PostgreSQL and Elasticsearch databases are used to store the resulting measurements. In a smart home, the wireless sensor ACS712 was used to monitor the flow of electricity (current and voltage) for a household device. The user can share data about electricity consumption and costs with a third party via the private IPFS (InterPlanetary File System) network. A third party can download all the energy consumption data for a device or many devices from the platform for 1 day, 3 months, 6 months, and 1 year. The studies on the development of energy-efficient technology for home devices benefit greatly from the gathered data. For security in the system, it is preferred to run Keyrock Idm, Wilma Pep Proxy, and Orion Context Broker in HTTPS mode, and MQTTS is used to retrieve sensor data. The experimental results showed that the energy monitoring system accurately records voltage, current, active power, and the total amount of power used and offers low-cost solutions to the users using household devices in a day.展开更多
文摘Sm-based perovskite-type oxide (SmMeO3: Me = Cr, Mn, Fe, Co) thin-films could be synthesized by a wet-chemical method using an acetylacetone—Poly(Vinyl Pyrrolidone) (PVP) polymeric precursor method at 750℃. The perovskite-type oxide thin-films were tried to apply an acetylene gas sensor based on AC impedance spectroscopy. Among the oxides tested, SmFeO3 thin-film sensor showed good sensor responses in which the AC impedance at 20 kHz was depending on acetylene gas concentration between 2 ppm and 80 ppm at 400℃.
文摘The design and performances of a high dynamic range DC-AC current sensor utilizing Giant Magneto-Impedance (GMI) are presented. The sensor is based on a GMI element with negative feedback. The sensing element is a 30 μm diameter GMI Co-based amorphous wire. It is curled to a toroidal core of 2 cm diameter. A bias magnetic field of about 650 A/m is applied to the GMI element to obtain an asymmetric GMI effect. A strong negative feedback is introduced to ensure linearity in a wide dynamic range. Analog conditioning electronics was fully developed. This includes a square wave oscillator based on an inverter trigger;a peak detector and a high gain amplifier with zero adjust. The GMI element is driven at a 3 MHz frequency and 5 mA peak-to-peak current. The closed-loop operations are investigated and the performances of the sensor are presented. DC current measurements are performed. The sensor exhibits good sensitivity and very good linearity, free from hysteresis, in a wide dynamic range of ±40 A. The sensitivity is about 0.24 V/A and the linearity error is about 0.02% of the full scale (FS). The hysteresis error is smaller than the measurement accuracy. AC current measurements using the developed sensor have also been successfully achieved. The sensor bandwidth in closed-loop was about 1.7 kHz.
文摘Energy demand will continue to rise as a result of predicted population growth. In this work, a user-friendly home energy monitoring system based on IoT is described, which is capable of collecting, analyzing, and displaying data. Users register their sensors and devices on the monitoring platform. PostgreSQL and Elasticsearch databases are used to store the resulting measurements. In a smart home, the wireless sensor ACS712 was used to monitor the flow of electricity (current and voltage) for a household device. The user can share data about electricity consumption and costs with a third party via the private IPFS (InterPlanetary File System) network. A third party can download all the energy consumption data for a device or many devices from the platform for 1 day, 3 months, 6 months, and 1 year. The studies on the development of energy-efficient technology for home devices benefit greatly from the gathered data. For security in the system, it is preferred to run Keyrock Idm, Wilma Pep Proxy, and Orion Context Broker in HTTPS mode, and MQTTS is used to retrieve sensor data. The experimental results showed that the energy monitoring system accurately records voltage, current, active power, and the total amount of power used and offers low-cost solutions to the users using household devices in a day.
