Working with the previous circuits, this circuit resets after 1 second. The circuit is from Radio Electronics magazine, August 1984. The time can be changed.
This circuit was found in a 90s Popular Electronics. The components are from the era. R3 must be...
This circuit is from the magazine La Radio per Tutti of 1926. The primary and secondary coil have...
The sensor for this circuit, found in a 1992 publication, is a phototransistor. The power is...