The integrated circuit used in this project is not common today, as it was obtained in the Linear Applications Handbook of the National Semiconductor of 1994.
Using a 4046 PLL this circuit recognizes a 1.6 to 1.8 kHz tone by driving an output LED. The...
In the figure we have a circuit in which the second tone recognizer remains disabled until the...
This filter can be implemented with almost any operational. The power suppply must be symmetrical. ...