It serves as a reference, since today we can have simpler and more compact solutions. This circuit is from an Electronics Experimenter Handbook from 1992. The integrated circuits are from that time.
This circuit is suggested by Texas Instruments and can be used on an assembly line to drive an...
In the figure we have a interfacing circuit of TTL logic as CMOS logic using a 6N139 optical...
This alarm with sensors in series and parallel was found in the 1995 Encyclopedia of Electronic...