Looking for a 'tripwire' flashlight

[Dave_H]

In case anyone's interested I found a clearout at Ikea, a metal strip designed to mount inside large filing cabinet, so that two LEDs which come on when the door opens. Product is called OMLOPP (love those Swedish (?) names). https://www.ikea.com/ca/en/p/omlopp-led-light-strip-for-drawers-aluminium-colour-70435730/ It has two small SMT white LEDs, operates from 12-24v dc, PSU not supplied. It uses an IR LED+detector (not PIR) which senses door proximity; seems to work well. Put small opaque object or some tape loosely over detector and connect to the "trip" cord. Either that, or position so it comes on when a door opens. Form factor is long/thin and could be attached to wall, door or ceiling. Light consumes 130mA at 14v (1.8W) dropping to 60mA at 12v (0.7W). Downside is standby current ~4mA which is not bad for a larger 12v battery (7-9Ah gel cell), could be a problem for smaller ones. If the OP doesn't find this useful, someone else might. Dave

 

[turbodog]

I built something from parts already but thanks for the info.

 

[Ken_McE]

When you walk through the door, the string pulls the pin out, microswitch contacts close, and leds come on.

How do you reset it?

 

[Ken_McE]

Turbodog, I know that you don't want to run line voltage through the wall of the shelter, that you see it as a safety hazard. What would you think about running 12 volts DC in through the wall? You could have a smart battery tender plugged into the garage somewhere and have a good sized 12 volt battery that lives inside the shelter and is always available to run things.

 

[turbodog]

How do you reset it?

Push the microswitch down again, and reinsert the pin beside it into the hole in the wood backboard. If CPF pictures were not such a pain I would throw up a pic.

 

[turbodog]

Turbodog, I know that you don't want to run line voltage through the wall of the shelter, that you see it as a safety hazard. What would you think about running 12 volts DC in through the wall? You could have a smart battery tender plugged into the garage somewhere and have a good sized 12 volt battery that lives inside the shelter and is always available to run things.

Would rather not have live a/c anywhere near the steel structure. I'm in good shape currently. The 'tripwire' light is in place along with 2 small spare lights, 2 small 'd' cell powered fans, some water, and spare batts for the fans.

We have a LOT of large tall trees around the house. They could come down and push live wires into areas that I would rather them NOT be in.

 

[turbodog]

After the new forum changes, it's much easier to post pictures.

Not my best work... but it's solid.

123 cell in a holder, reinforced with good old electrical tape.
12 gauge copper wire with 4 leds
microswitch
trip device tied to string that goes across doorway
held to steel wall with a couple of rare earth magnets

unit is in the far corner where you won't brush up against it

 

[turbodog]

Looks like I could have used one of these... the 'aaa' battery is not great for long term stability though. Would need a lithium cell in there.

 

[Ken_McE]

Clean. Simple. Effective. Not pretty, but doesn't need to be.

Well done!