This input circuit for an oscilloscope was found in Radio Electronics from the 90s. The operating circuit is from that time, and a modern equivalent can be tried out.
This circuit with a double-gate MOS transistor was found in a Popular Electronics from the 90's....
This photoelectric cell light relay was found in Radio Electronics magazine from April 1958. The...
This circuit was obtained in the publication 101 Electronics Projects of 1979. The circuit can be...