We found this circuit in a Popular Electronics of the 90s. The circuit can be easily mounted today, as the components are common. The SCR can be the TIC106.
This circuit is from a documentation on Motorola interfacing techniques from 1975. The Darlington may be...
This circuit is from an old Electroics Now. Its purpose is to protect the fax and modem lines of...
This 8-channel converter was found in a 1970s American documentation. The integrated circuits used are...