This circuit is from an old documentation, making use of an operational of the time. The circuit can be adapted to use modern components. The power supply must be symmetrical.
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...