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 filter, from an audio publication from 1977, passes the frequency range corresponding to the...
In the figure we have three voltage doubler configurations that can be used in high and low...
This circuit was found in Motorola documentation from 1966. The lamps are according to power and...