Quote from thekillman
A lens -from a gameplay perspective- emits a beam when it recieves light from the receiving end. I also just realized that you don't have to put too much work into it.
You could easily replace your lower red "wireless redstone" block with a lens/lightblock combo, and the upper red thingey with a detector block.
Make it off by default so when the DB recieves power, the elevator descends. Also, make it connected to a flip flop (block dispenser with 1 half slab and 1 full block), so the pulse duration is not important.
You would only have to push a button or whatever, then the elevator comes down. At the top, you simply plug a button into the power line from the detector block to the t flip-flop, and you're all set.
Alright, i just had trouble understanding how exactly it functions. Thanks to all the people that helped explaining it to me. I'll experiment with it further today.