We found this circuit in a 1980s Motorola documentation. The circuit makes use of common operating and the voltage depends on the used type. The components are for a frequency of 500 Hz.
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...