A New Generation of Multijunction Thermal Current Converters

Lipe, Thomas E.

doi:10.1109/tim.2016.2613405

Cited by 10 publications

(3 citation statements)

References 9 publications

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“…The devices designed for these larger currents should have a heater dimension of 5 mm 3 3.8 mm. A moat 1 mm wide is used to isolate the heater from the surrounding substrate, as shown in Figure 35 (Lipe, 2017).…”

Section: Development Of Ac Voltage Standardsmentioning

confidence: 99%

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Development of Electrical Quantities Primary Standards

Ali

2021

Transactions of the Institute of Measurement and Control

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The developments of primary standards for electrical quantities that practically realize the electrical units such as ampere (A), volt (V), ohm (Ω), and farad (F) are introduced in this manuscript. These quantities are achieved in consistency with their definitions. According to the new definition of ampere, current can be realized directly such as single electron transport (SET) pump or indirectly using Ohm’s law. For the SET pump, developments are ongoing as trials to obtain higher current values with lower associated uncertainty to be suitable for metrological applications. With the discoveries of the Effects of Josephson and quantum Hall, it has become possible to consider quantum electrical standards that relate the volt and ohm units to h and e through the Josephson and the von Klitzing constants, respectively. The dc programmable Josephson standard was developed to overcome the problems of conventional standards such as stability and noise immunity with lower cost. Developments are continuing on ac Josephson standards to improve performance and increase output voltages and frequencies. For ac voltage measurements for voltages up to 1000 V, thermal voltage converters are introduced to extend the traceability for measuring the ac voltages in the frequency range from 10 Hz to 100 MHz where quantum-based ac standards still have limitations. Thermal current converters are used as the most accurate and precise standard for measurement of ac currents. The realization of ohm is done by the quantum Hall effect through a quantum Hall resistance (QHR) standard. Developments are occurring to make it simpler, more precise and accurate. The efforts that have been made to increase the values of the resistance quantum hall standard to disseminate its accuracy to other standard resistors to help in industry are also introduced. The farad is practically achieved by the calculable cross-capacitor. The calculable capacitor acts as the ac impedance primary standard because it can transfer the traceability to other impedances by using bridges such as the quadrature bridge. The development is occurring on its displacement sensing system to allow greater accuracy.

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Section: Development Of Ac Voltage Standardsmentioning

confidence: 99%

“…The assembly consists of a PCB made to mount eight 1 A MJTCs which have been connected in parallel, as shown in Figure 36. They are enclosed in a module with appropriate input and output connectors (Lipe, 2017).…”

Section: Development Of Ac Voltage Standardsmentioning

confidence: 99%

Development of Electrical Quantities Primary Standards

Ali

2021

Transactions of the Institute of Measurement and Control

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“…Due to appearing new calibration commercial instruments that required calibrations at higher current and frequency ranges, up to100 A at 100 kHz, an ac-dc current transfer comparator and high current standard shunt were designed [10]. However, these shunts extend the range of the current measurements, but they have many drawbacks at higher currents such as the variation of the resistance as a function of the frequency, thermal drifts, the inductance of the resistive element and greater errors from skin effect especially at high frequencies [11]. Also, its cost is very high.…”

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confidence: 99%

Establishment of new automated multi range thermal current converter

Abdelmonaem

Ali

Shatla

2023

IJPEDS

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<p>A new automated multirange thermal current converter (TCC) has been designed and implemented at the National Institute of Standards (NIS), Egypt. Five single junction thermal current converters (SJTCCs) have been connected in parallel on PCB with an LCD, keypad and a microcontroller to control a five fast switching relays. This TCC has been designed to cover the ac current ranges from 500 mA to 5 A at frequencies from 40 Hz up to 100 kHz. The construction of the new automated TCC has been presented to solve some problems of using shunt resistance at high currents. Furthermore, a new automatic calibration system has been established to calibrate the established TCC against another standard TCC. This software program has been specially designed using MATLAB program to overcome the problems of manual calibration and measurement. The expanded uncertainties are estimated for all ranges at different frequencies and also, the ac-dc differences. The performance of the new automated TCC is also evaluated by comparing its accuracy by measuring ac currents at different frequencies with the performance of a traditional TCC.</p>

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