Found in Electronics Now this circuit is indicated for operation at the output of audio amplifiers. The circuit is powered by 12 V from the amplifier itself or from another source.
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...