A General Purpose Transistorized D.C. Amplifier
R Parameswaraiah, P.E. Sankaranarayanan · IETE Journal of Research · 1969
The paper deals with the construction of a general purpose transistorized differential d.c. amplifier having a high common mode rejection ratio of 80 db., low long time drift of 10 μV./°C., and a gain of 1000. High gain n-p-n planar silicon transistors, available in the country, are used throughout. The first stage is operated at equal Vbe to reduce substantially the thermally induced drift and sensitivity to power supply variations. The amplifier operates well with low resistance sources like thermocouples, strain gauges, etc.