Found in an EEE from 1970, this circuit supplies a voltage of 12 V DC x 10 mA current from the power grid. The NOR or NAND port used is TTL.
This 1950's circuit used one of the first commercial transistors and had two stages for audio...
Using integrated circuits from the time, we found this audio compressor in an English publication from...
This is an experimental crystal radio that uses no power source. The antenna must be very long (at...