This Hughes circuit is from 1968. Equivalent modern components can be used. The input impedance is 1000 M ohm.
Found in Linear Technology documentation from the 1980s, this circuit has an accuracy of 0.01%....
This amplifier circuit for listening was found in a book by Hugo Gernsback from 1960. The...
This circuit is from a current regulator up to 1 A, ie a constant current source. The LM320...