This circuit is from a 1965 General Electric manual. It uses components from the time that admit equivalents. The SCR can be the TIC106 and the LDR of any type.
This circuit was found in an American documentation from the 90's. What it does is provide at the...
Found in old documentation, this circuit is tuned to pass signals below 245 Hz with a level of...
This series LED circuit was found in the February 1992 issue of Radio Electronics magazine. The...