This circuit is from the LM107 manual. This operational is from the 80s, but the configuration is valid for any operational. The formulas give the gain of the circuit.
This circuit was found in an Electronic Design from 1967. The circuit uses two triacs being T2...
Found in old American documentation, this circuit can use crystals between 27.5 and 33 MHz...
This shield from the 60's uses a germanium transistor of the time and a common type of relay of...