This circuit was found in 80's Popular Electronics. Transistors are commonly used. The potentiometer R5 adjusts the gain.
This circuit was found in the SGS manual of linear integrated circuits of 1982. The CMRR depends on...
In the figure we have a receiver for frequency modulated light signals (see the transmitter in...
In the figure we have a high stability voltage reference, providing a voltage of 10 V at the...