@NeverDie Thank you for sharing the device you use. I am based in eu and 240 V ac and I think i will just pick one with lcd that can show the highest range even without sounding alarm. Just to check if it is of any concern to me. My wife got candy canes, 7 sets 2xAA battery operated modules containing 40 leds each and i am trying to find a way to power them and wire them to one power source. Reading online it looks to be over complicated with so many things to calculate. This is just a side not not relevant to this post and the reason i didn't reply to your posts.