Found in a 1980s American documentation, this circuit operates with 5 V signals requiring 55 cycles of 500 Hz for tone recognition. The circuit can be adapted to operate with other frequencies.
Indicated for applications in the analysis of logic circuits, this circuit was found in 90s Radio...
This circuit is from 1977 documentation, and high current equivalent transistor must be used. The...
Found in an Electronic Design, this circuit makes use of general-purpose bipolar transistors. The circuit...