Found in an English documentation, this circuit serves as a receiver for modulated sources of ultrasound. The sensor is a ceramic capsule. Transistors are general purpose types.
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...