This circuit, which can be found elsewhere on this site, detects positive pulses of a signal. The circuit was suggested in Texas Instruments documentation from the 1980s.
This circuit can be used in demonstrations or science fairs. The circuit uses headphones and can...
We found this wiretapping circuit in a publication from the 90s. The circuit allows the cable...
This circuit uses a resonant reed switch at the trigger frequency. The circuit is from General...