This circuit is valid for other comparators of the same series. In this case, a lamp is excited, but an LED can be used in series with a resistor or other load. The transistor admits equivalent.
This circuit was found in a 1969 CQ magazine. It is intended for coupling telephones to radio...
This circuit is from American documentation from the 1980s. The circuit can make use of any common...
We found this circuit in a 1977 documentation. The integrated circuit used is 4001. The signals...