The integrated circuit used in this circuit from a 1987 documentation is no longer common today. This circuit can generate a multitude of different sounds and this circuit is an example of application.
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...