Development of a thermal voltage converter with calculable high‐frequency characteristics

Abstract

A thermal‐voltage converter for high‐frequency (HF‐TVC) AC–DC transfer standard has been developed. The HF‐TVC was designed such that the frequency characteristic is calculable from the shape and dimension of the input circuit. A new multi‐junction thermal converter element (JSTC04) has been developed, which has a simple and straight heater configuration to minimize the parasitic impedances in the input circuit. The AC–DC difference of the HF‐TVC was evaluated by two independent methods, with agreement better than 7 µV/V up to 1 MHz. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Fabrication of Thin Film Multijunction Thermal Converters With Improved Long-Term Stability

“…The ac-dc transfer differences in the frequency range from 10 to 1 MHz can be reduced to less than 10 μV/V by changing the shape and dimension of the input circuit. As the high-frequency characteristics of our TFMJTC were described in [18], here we report the low-frequency ac-dc transfer differences and thermoelectric transfer difference.…”

“…thermal ripples [18], [21]. The temperature coefficient of the nonannealed heater film is in the range of 50-100 μ / /K.…”

“…The thermal time constant and temperature coefficient have a major influence on the low-frequency ac-dc transfer difference [18], [21]. The thermal time constant τ = C/G is determined by the ratio of the heat capacity C to the heat conductance G [21].…”

Multijunction thermal converter with improved frequency characteristics between 10 Hz and 1 MHz

“…(i) AC to low‐frequency AC difference (AC‐LF) measurement and (ii) AC–DC difference comparison measurement. The AC‐LF measurement was performed using a high‐precision DSS (digital sine‐wave synthesizer) circuit as the reference standard, while the AC–DC difference comparison measurements were performed using a low‐frequency model, JSTC05, as a reference standard 5. The results of the measurements are summarized in Fig.…”

“…In this paper, a new MJTC element, Type‐JSTC06, with improved frequency characteristics for a wider frequency range (10 Hz to 1 MHz) is described. We have so far developed two types of precision MJTC elements, i.e., Type‐JSTC04 [4] and Type‐JSTC05 [5]. The high‐frequency model, JSTC04, was specially designed to comply with the requirements for the ‘self‐calculability’ of the frequency characteristics higher than 10 kHz.…”