This notch filter was found in National Semiconductor documentation from the 1980s. Operational amplifiers are from that era. The configuration can be adapted to use modern operational amplifiers.
This circuit is from a 1954 transistors publication. The transistors are the CK722 among the first...
This sophisticated circuit of the coin-toss game was found in an American 1980s documentation. The circuit...
This windshield wiper interval was found in an old documentation. The SCR can be the C106 and the...