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.
This squelch is activated by its own noise, acting automatically. It is used in communications...
This circuit for a simple alarm system was suggested in an article in Electronics Now magazine. The...
Found in American documentation from the 70s, this circuit uses components of the time, uncommon...