T.I. Chen Blog

  • 2020-05-07May

    Mini DC Split-core, Hall Effect Sensors

    The 16mm opening and 24mm opening mini spit-core, open-loop, Hall Effect sensors are ideal for retrofitting DC sensors in tight physical environments. The HOS016 and HOS024 families of mini split-core, open loop Hall Effect current sensors offer fast and easy installation into existing electric power distribution systems where space is a premium. The split-core design […]


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  • 2020-01-30January

    DC Leakage Current Sensors

    A direct current leakage current sensor is used to measure the milli-ampere level DC current in a primary conductor with both AC (alternating current) and DC (direct current) components. The sensor uses the “magnetic modulation” technique to offset the AC component in the primary conductor by introducing an offsetting magnetic field. The offsetting magnetic field […]


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  • 2019-05-21May

    AC Current Transformer Burden

    The AC current transformers used for the accurate measurement of AC electric currents are designed to transform the AC primary current to a proportional AC voltage signal or a lower proportional AC current signal level that is appropriate for micro-processor based systems. The VA (Voltage – Amperage) burden that is imposed on the AC current […]


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  • 2019-04-16April

    Accuracy Class for Current Transformers

    The accuracy performance of an AC current transformer’s primary current to secondary signal transformation (where the secondary is either a current or voltage) is stated as Accuracy Class. The Accuracy Class for current transformers is measured in accordance with the IEC61869 standard. The IEC61869-2 standard specifies transformation accuracy for current transformers at different percentage levels […]


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  • 2019-04-16April

    DC Current Measurement

    The non-intrusive measurement of a DC current is accomplished through the use of electronic sensors that use the Hall Effect to monitor and measure electrical currents. Hall Effect sensors used for DC current measurement are configured with an opening for the primary conductor. Matching the opening size to the outside diameter of the primary conductor […]


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  • 2019-02-07February

    AC Voltage Measurement, Intelligent Devices

    The accurate measurement of AC Voltage is complicated by the necessity to minimize the burden the measuring instrument places on the primary circuit. The incorporation of a 1:1 current style voltage transformer in the AC voltage measuring circuit offers several advantages. Features A minimal burden on the primary voltage circuit, with essentially zero primary circuit […]


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  • 2019-01-14January

    AC Current Measurement, Intelligent Devices

    The Supervisory Control and Data Acquisition (SCADA) systems used by electric utilities to manage the distribution of electric power are highly dependent upon the intelligent, micro-processor based devices installed throughout the electric power distribution grid. These intelligent devices acquire in real time the critical performance measurements (e.g. current, voltage), transmitting that information back to the […]


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  • 2018-12-03December

    AC Electric Power Monitoring and Measurement Sensors

    Retrofitting Existing Distribution Networks The current generation of electric power AC current sensors that are suitable for retrofitting existing distribution networks have obtained a level of accuracy capable of near revenue grade metering. These split-core sensor designs permit the installation of the AC current sensor without taking the primary conductor off-line. The standard solid-core AC […]


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  • 2018-09-17September

    Micro-Grid, Option for Restoring Electric Power to Puerto Rico

    I have read several interesting stories of organizations proposing and installing Micro-Grids as a means of restoring electric power to areas in Puerto Rico. The Micro-Grid systems incorporate electric power generation, electric power storage and/ or smart-grid connection to the electric utility distribution network. The installations goals are; Restoring electric power. Providing backup to critical […]


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  • 2016-09-23September

    California Zero Net Energy Program: Part 2

    The California Zero Net Energy program discussed in the previous post will have a significant impact on new construction. The average residential electric power usage in the State of California is 6,741 kWh per year (U.S. Energy Information Administration) or 18.5 kWh per day on average. Presumably a residential home will generate electric power using […]


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