So, I really don't see how these work. I assumed you'd put the combinator down, say hooked up to some source like a chest, and it would have an "output" of whatever the max value was, but I connect wires, and it just sits there. Must be something I'm doing wrong. Do you have a pictures or a recipe of a working config to share ?

ok, I think I've got it.. the way it works out what the input & output are, is you have to include the INPUT and OUTPUT signals on the rd and green wire, to indicate which is which..
However, as someone else mentioned, it then always sends "1" as a signal

I'll look into it when I get a chance