Nedavni sadržaj od ronw1309

I have 4 diodes and i need to make that when I disconnect at 1, the 1 and 2 diodes are activated, when 2 is 2 and 3, and when 3 is 3 and 4. This is the most stupendous example, but if anyone could put me in a little, what it is, how do they work, where can I find something that goes in that...