This circuit makes use of an operational amplifier from the 80's. The circuit can be implemented with modern transconductance operational and TTL logic working as a shield.
Found in a 90s Popular Electronics, this circuit allows to select the operating ranges between...
This circuit was obtained in a 1960 transistor manual from Sylvania. The circuit uses small...
This simple unijunction circuit is from a Radio Electronics from July 1963. It can be assembled with a...