This circuit is from a Radio Electronics from March 1970. The integrated circuit used is one of the first for this purpose, being improved later leading to types that succeeded it.
This circuit was adapted from an Italian publication that no longer exists. This is “Onda Quadra”...
This circuit was obtained in an Electronic Engineering of the 90s. The operational amplifiers and...
The basic component of this circuit is a general-purpose SCR. The voltage is according to the...