We found this circuit in the 1982 SGS linear integrated circuit manual. The L149 is not common today and the circuit can be implemented with equivalents.
This circuit, from the 90's, is intended for operation with vinyl record players of the time, as...
Using a zener diode it is possible to change the linearity of the scale of an analog instrument by...
Found in American documentation from the 1980s, this circuit prolongs the ringing of a doorbell or chime...