A Fast Response LED-Logarithmic Electrometer

Abstract

The response time of LED-logarithmic electrometer is studied. The improvement of response time using a phase compensation technique in which a current variable resistance is inserted between the detector and input of the electrometer, is discussed particularly at low current levels. Small signal analysis of LED-log electrometer operated in a conventional mode and a resistance in series with log element is carried out to evaluate the relation between the response time and stability.

Indexing terms:

• LED
• Log electrometer
• Response
• Stability

Additional information

Notes on contributors

Y B Acharya

Y B Acharya, obtained MSc Tech (Electronics) from Birla Institute of Technology & Science, Pilani (Rajasthan) in 1973. He joined Planetary atmospheric Sciences Area of Physical Research Laboratory, Ahmedabad as an Electronics Engineer in August 1973 and since then he is working on the design and development of various spaceborne instrumentation for the measurement of ionospheric parameters, minor constituents and electrical parameters using rocket as well as balloon-borne techniques. He has been responsible for designing photometers, ultra low current measurements systems, automatic gain switching system, suntracking multi-channel photometer and groundbased check-out systems etc.

Presently he is also associated with the Lidar programme of Physical Research Laboratory, Ahmedabad for the study of the earth's atmosphere.

He is Fellow of the IETE and has more than 30 publications to his credit in National and International journals.

P D Vyavahare

P D Vyavahare is Professor-in-Charge of the Dept of Electronics and Tele Engg of Shri G S Institute and Technology and Science. He received his BSc and MSc (Physics) Degree from University of Indore in 1972 and 1974, respectively, and M Tech and PhD from IIT, Bombay in 1976 and 1994, respectively. He worked in Tata Institute of Fundamental Research (TIFR) from 1976 to 1982 as a Communication Engineer. Since 1982 he is working at Shri G S Institute and Technology and Science, Indore. His interest include Electronics and communications. He has more than 12 publications to his credit in reputed journals. He is Fellow of the IETE.