https://www.google.com/search?q="voltage+slope+detector"+-patent+-fm&tbm=isch
https://www.google.com/search?q="voltage+slope+detector"+-patent+-fm&tbm=isch
← now the 2-nd such schematic on Earth
https://www.google.com/search?q="voltage+slope+detector"+-patent+-fm&tbm=isch
← now the 2-nd such schematic on Earth