We found this circuit in the May 1972 issue of Radio Electronics magazine. Its purpose is to teach logic using integrated circuits of the TTL family. The 5 V power supply is included.
This SCR relaxation oscillator was found in an 80's Electronic Design. It flashes a small...
We found this shield circuit in a 1991 technical documentation. The phototransistor can be...
This circuit for old photo enlargers was found in a 1970s RCA manual. The components are from the...