@DanielP there are 8 sections (16 relays, 8 to turn on, 8 to turn off), so 40cm … which is pretty good for spraying.
@Larsvest
it works, but will the teejet switch box enjoy working like this for a long time? I don t know .
Here is an interesting approach from @Math which corresponds if I understood correctly to what Brian suggested to me.
It’s in French .