Found in a Popular Electronics from the 90s, this circuit can act as a transmitter for an audio link. The output transistor admits a higher power equivalent, depending on the LED.
This logic circuit can indicate both TTL (5 V) and CMOS (5 to 12 V) output levels, operating with...
We found this circuit in an old American documentation, from 1971, but the component used is still...
This circuit is from an Italian magazine Radio Elettronica of January 1977. The circuit shows how...