The 1: 1 transformer on this circuit found in a 1967 Electronics World can be wrapped around a small ferrite rod. The circuit operates with 600 to 6 000 Hz control signals.
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...