Seems I am seeking something hard to be done or impossible. I really care about the uino not to be harmed as well as the place of course and I want some cheap solution that won't cost more than the uino itself but idk it's seems bit complicated to achieve such thing.
Well it seems to me that you keep moving the goal posts. A fuse in the battery would stop it bursting into flames. And would seem to answer this latest objection.
Thanks grumpy and everyone and really sorry for any bothering :S. I really appreciate all your time and help, guys. Hope I wasn't that annoying lol :S...
Thanks again,
Max ^^
@grumpy sorry for bringing this topic up again but wondering how to calculate the amount of fuse needed just for the battery to feed the opt isolator and to avoid the main outlet current to reach battery by burning the fuse before it reach it?
Btw, I am following your scheme u provided in previous post.
Thanks alot,
Max
Just use as small a fuse as you can get. You need it to blow at anything over 40mA but you can't get fuses that low so use the lowest you can get, maybe 250mA.
maxwell1:
but what I am doing is I try to connect a door switch to the uino but as I need to be 100 percent secure that the uino won't be destroyed if someone intentionally cut wires of the switch and insert it in 220v electric outlet for sake to destroy the project
If this is for a security project or security system, then the switch and wires would usually be on the internal side of the door, where somebody isn't supposed to be able to access, right?
If somebody does want to tamper, then set up some kind of motion detector, alarm, lights, and camera to catch the culprit that is trying to interfere with your door switch.