This circuit is from a 1967 documentation. It consists of a sensor for memories used at the time. It can be made with modern equivalent transistors. Note the 4 V symmetrical power source.
This amplifier with very high input impedance was suggested by Texas Instruments in a manual of...
This circuit is from a documentation from the 70s. The circuit uses logic gates of the time, which...
This 80's circuit uses a germanium transistor like the AC121. The circuit has an output...