Found in a Popular Electronics from the 90's, this circuit is used to recognize the frequency of a modulated infrared signal. The LM567 circuit must not be supplied with voltages above 9 V.
The integrated circuit used in this project is unusual. However, we can take advantage of the...
This alarm, found in a 2002 documentation, uses several sensors and has a 12 V supply, not...
This instrument was found in a publication for radio amateurs in 1973. The tuned circuit consists of...