An FET Operational Amplifier Circuit for Photoelectric Photometry

Volume 1 number 2 (1972)

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Arthur J. Stokes

Abstract

Recent improvements in solid state semiconductor technology have resulted in a number of manufactures (Intersil, Signetics, Fairchild) offering low cost operational amplifiers with input resistances of the order of 10^12 ohms and input currents of the order of a few picoamperes. These components are ideal for the low current measurements made in stellar photometry. Along with low cost, these components are very small and extremely stable. NOTE: an erratum is published in JAAVSO (1973) Vol. 2, 48