This 10 A solid state relay was found in a 1980s documentation. It can work as a shield and implemented with modern equivalent transistors.
This old circuit that makes use of germanium transistors, can be modernized with the use of...
The circuit presented was suggested by Texas Instruments in an opto-electronics manual. The...
This 4-digit digital clock for hours and minutes with CMOS integrated circuits was found in a 1995...