In fact, this circuit from the 60's applies to photographic printers of the time, timing the lighting of a 20 W lamp. The components are from the period.
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...