Using the 723 integrated circuit, this circuit was found in an article on power supplies in the August 1971 Radio Electronics magazine. The transistor may be the BD136 on a heatsink.
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...