Laser switch - Page 1
Forum section: electronics / beginners

author: Twofish
author_rank: Newbie
timestamp: October 13, 2025, 10:02:41 pm
content: Hello.I feel like I should explain a couple things before I ask my question. I have very little knowledge of or experience with electronic devices. I can connect a car battery to a charger without making sparks or explosions. I can strip wire and crimp connections. I can install electronic devices in my boat without starting a fire. I can re-wire the lights on the trailer. I know how a fuse works and why they are important. That about covers it.The place where I live has a pool and the filter room has no door. The missing door does make it easy to work on the pool equipment, etc. but small critters get in there sometimes and make a mess.The obvious solution to this is to replace the missing door but I don't own the place and the owners don't want to put a door in.I've been trying to come up with a way to keep the rodents out of there and the garage door gave me an idea. Most electric garage doors have that little laser thing along the floor that stops the garage door from going down if something interrupts the beam of light.I'm wondering if there is a similar device that, instead of cutting power off, will turn the power on when the beam of light is interrupted.For example, if a rodent walks through the door and breaks that beam of light, it will be hit with a bright light or a loud noise or a stream of water or a bolt of lightning or something that will discourage it from going any further.Is there a name for this type of switch?

author: themadhippy
author_rank: Super Contributor
timestamp: October 13, 2025, 10:26:08 pm
content: Try "ir beam break"

author: ledtester
author_rank: Super Contributor
timestamp: October 13, 2025, 10:27:35 pm
content: beam interrupt sensoror:https://www.adafruit.com/product/2168

author: kite31
author_rank: Regular Contributor
timestamp: October 14, 2025, 12:31:42 am
content: ...or if they are too persistenthttps://eos-aus.com/defence/high-energy-laser-weapon/

author: Psi
author_rank: Super Contributor
timestamp: October 14, 2025, 12:58:23 am
content: Another thing you can do, in addition to discoursing them from trying to enter, is get one of those one-way live catch traps and add a tube to it that leads back outside.So any mouse/rat that gets inside eventually finds its way into the trap while exploring and then has no choice but to go back outside.Otherwise they may not want to leave due to warmth.The concept works well for an automatic system that gets mice out of your roof at least.

author: Stray Electron
author_rank: Super Contributor
timestamp: October 14, 2025, 01:17:22 am
content: I'm thinking that a hot wire fence like that used on a farm might be more effective.Yes, I know,shocking!Why won't the owner replace the door? After all it's his building and if the rats, mice, etc get in there and damage the wiring or his machines then he's the one that will have to pay for the repairs. I'm thinking that exposure to rats, mice & squirrels and their feces might also be a health threat to the residents so you might also want to get the health department involved. And since that is an equipment room the door is probably also supposed to be there as a fire stop so the Fire Department or the Fire Marshall and/or Code Enforcement might also want to get involved.

author: Twofish
author_rank: Newbie
timestamp: October 15, 2025, 05:55:45 am
content: Quote from: Stray Electron on October 14, 2025, 01:17:22 amNo, it's family. And the house will probably be demolished within a year or two. It's an odd sized hole so I would have to order a custom door, hang it, paint it, and it would still have a gap at the bottom because the concrete inside the room isn't level.I'd like to have a laser cannon that would kill anything that is less than an inch tall that tries to go in there but I'm sure that would get me in trouble.

author: themadhippy
author_rank: Super Contributor
timestamp: October 15, 2025, 01:16:58 pm
content: Quotecut the bottom of the door to suit the profile of the concrete ,simples.

author: Poroit
author_rank: Frequent Contributor
timestamp: October 17, 2025 07:38:08 am
content: G'day Twofish,I proved this recently.Cloudy Ammonia works well on Rodents,Possums etc.as they hate the smell.Put some in some upturned jar caps and place them around the trouble areas.Monitor their droppings and you should se them disappear.Top up the lids as required.