As nothing more than a life long electronics enthusiast without a degree ot her than popular electronics magazine and a distaste for math, I have the f ollowing embarrassing question for the design wizards.
My design skills often times are "if it works for a couple of days and does n't get hot we're good to go".
So there's something that actually I've done for a long time without proble ms but my guess is there probably is one somewhere.
Say you have a circuit on a pcb and it does this and that and your power su pply is ample with a simple LM317 regulator or whatever.
Ok -- now to interact with your circuit you have possible long runs (say 10
0' max) of good gauge wire that simply open/close the ground circuit to an optoisolator(s) (which is located on the pcb). And not just 1 but several ( think burglar alarm etc). ground closes -- opto triggers otherwise it's idl e.Now I need an education on "possible" flaws in doing this (although I've ne ver had a problem). I'm aware of any induced voltage through a lightning st rike down the block etc but what are you going to do about that? -- shit ha ppens.
Are there any nuances I'm missing with this? With the ground circuit basica lly being floated around everywhere? The same ground I'm using on the pcb? Should there maybe be some isolation (diode or something?) or also, would p roblems depend on the complexity of the circuit onboard?
Noise causing something? (.1uf is my favorite part so always use plenty of them). -- anyway hope this makes sense