Three countries in South America are jointly developing a reference system for measuring electric power up to 100 kHz. The objective is the construction of three similar measuring systems, one for each institute. The measuring system is described and its design requirements are presented. This project will contribute to provide calibration services in measuring ranges still not covered by the three institutes.

https://iopscience.iop.org/article/10.1088/1742-6596/733/1/012068/pdf

Trilateral South-American project: a reference system for measuring electric power up to 100 kHz - progress report

New transconductance circuits (V/I converters) are designed based on current mirrors and operational amplifiers. Their input/output characteristics and the influence of DC parameters are obtained. Experimental results were performed, comparing them with the simulated results. An electronic instrumentation circuit is designed based on one of the transconductance converters analyzed. The purpose of this circuit was to condition the response of an ion-sensitive field-effect transistor (ISFET) to measure pH. In the proposed application, the V/I converter presented provides the stability and accuracy of the ISFET operating point, making an easy characterization procedure and the design of multichannel ISFET-based measurement systems possible. Experimental results of the ISFET main electrical parameters were obtained, showing the feasibility of applying these new converters to instrumentation and electrochemical measurements.

Transconductance Converters Based on Current Mirrors Applied to pH Measurement Using ISFET Sensors

Because of anecdotal reports that magnetic fields from walk-through metal detectors may interfere with the operation of personal medical devices, interest has grown in the development of emulators that can simulate the magnetic fields produced by these metal detectors. This paper describes a system that can produce linearly polarized magnetic fields that have temporal characteristics such as those generated by some walk-through metal detectors. Because the electronic components are "off-the-shelf" devices and the coil can be readily fabricated, the system could be used by manufacturers of medical devices to conduct their own electromagnetic interference tests.

Development of emulator for walk-through metal detectors

Three countries in South America are jointly developing a reference system for measuring electric power up to 100 kHz. The objective is the construction of three similar measuring systems, one for each institute. The measuring system and the current status of the development of its modules are described here. This project will contribute to provide calibration services in measuring ranges still not covered by the three institutes both in ac-dc transfer and in electric power.

Trilateral South American Project: A Reference System for Measuring Electric Power Up to 100 kHz - Progress Report

This paper presents experimental evaluation of the performance of more than 25 production units of a 100 A, DC to 100 kHz transconductance amplifier. In addition to the stability, uncertainty, distortion, and frequency response, experimental results seem to indicate that the output impedance may be closely modeled by a parallel combination of a resistor and a capacitor in series with a resistor. This model is then used to estimate, and to correct for, the effect of load inductance on high-frequency, high-current measurements.

Evaluation of 100 ampere, 100 kHz transconductance amplifiers

A high-current, wide-band transconductance amplifier is described that provides an unprecedented level of output current at high frequencies with exceptional stability It is capable of converting a signal voltage applied to its input into a ground-referenced output rms current up to 100 A over a frequency range from DC to 100 kHz with a useable frequency extending to 1 MHz The amplifier has a 1000-W output capability /spl plusmn/10 V of compliance, and can deliver up to 400 A of pulsed peak-to-peak current The amplifier design is based on the principle of paralleling a number of precision bipolar voltage-to-current converters The design incorporates a unique ranging system controlled by opto-isolated switches, which permit a full-scale range from 5 A to 100 A The design considerations for maintaining wide bandwidth, high output impedance, and unconditional stability for all loads are discussed

O.B. Laug

Papers

A 100 A, 100 kHz transconductance amplifier