I think i heard of this one called "edge detector", if i'm not mistaken, you can achieve this with a single arithmetic combinator set up to do EACH * -1 output EACH
The wiring is the trick, if you have a constant combinator representing the input value, it need to be connected to the input and the output of the arithmetic with different colors of wire, and at the output, if the signal change, during 1 tick there will be "something" , and the next tick the arithmetic combinator will again nullify everything.