Originally designed to analyze the shape of light pulses from a flash for photographic applications, this circuit can be used in other applications. We found it in a Hands On from the 90s.
This filter that rejects determines frequency (notch) was found in a Popular Electronics of 1993....
Found in an Elektor from the 90's, this double door-bell drive circuit switches a relay by...
Using a 555 this circuit was found in old documentation, but it is still valid. | Clique na imagem...