The Curious Case Of A Very Sensitive PIR Light | Voltlog #315

This is a portable PIR activated LED light, it ships with some double sided adhesive backing and it’s pretty convenient to use around the house or when going camping I quite like it. It works with 4 AAA batteries and personally I use this inside a wardrobe to help me find stuff. If positioned correctly it turns on as soon as I open the wardrobe door. Because I like it so much I decided to order another one to place in a different closet for the same purpose. I don’t know if I ordered from the same seller, probably not, I just went on Aliexpress, did a quick search and ordered another one.

And here it is, after a long wait it finally arrived, at first sight they look identical, apart from a minor difference in the LED output color but that’s to be expected because whatever they can find at the market that particular day right?  But in practice I also noticed something different, the new one is much more sensitive in picking up movement, to the point where it turns on even if it’s behind a closet wall and I walk past by, or even behind a wall. I know it doesn’t make much sense, because these are supposed to be infrared sensors so they can’t pass through walls. But it must be bouncing the IR rays off the walls and it’s so sensitive that it is picking up those reflections, I would have no other explanation for this but if you do, let me know in the comments.