Motion sensor lights

[CraigieD]

Hi all. I've got a mate with a kid with severe learning difficulties. I've been helping them create a vibrant feel to their house, lots of colours, lighting etc.

They came up with the idea of using their central hallway as a space and want to put LED's in the skirting boards.

Fine I said. Not a problem.

However, they want to make them come on when you walk past each one and then go off again as you wallk away.

There'll be 20 LEDS, 10 on each side of a long corridor. I know You can have motion sensor light switches for a room, but what they're asking seems much more complex.

Any ideas on how I could achieve this effect for them?

 

[ban-all-sheds]

Even more LEDs. IR ones, paired with detectors on the other side of the hall - breaking the beam makes the visible ones come on.

I'd suggest building the thing in lengths of skirting trunking so that you can wire it up and bench test it before installing it, and also ensure that the relative alignment of the beams is the same so you only have to do one positioning adjustment on site. A digital camera sees infra-red, so you can use one of those for the alignment.

If there's space, and budget permits, you could build two panels full of visible and IR LEDs etc which would create an outline of the person walking by.

 

[CraigieD]

Even more LEDs. IR ones, paired with detectors on the other side of the hall - breaking the beam makes the visible ones come on.
....

If there's space, and budget permits, you could build two panels full of visible and IR LEDs etc which would create an outline of the person walking by.

Cheers, new there'd be a solution. So basically, wire each IR LED to a sensor on the other side of hte hall.

So the current only flows to the LED if the sensor detects a break.

 

[stillp]

The only problem is that standard LEDs have a wide beam angle, and most detectors have a wide acceptance angle, so every detector will 'see' every LED unless you can improve the optics. You'll need to mount the LEDs and the photodiodes, or whatever you use to detect them, down some tubes to limit their field of view.

 

[bernardgreen]

If the hall way is carpetted then use a few small pressure pads under the carpet to switch the LEDs.

 

[stillp]

Wouldn't a couple of "follower" rope lights give almost the same effect much more simply?

 

[compynei]

http://alan-parekh.com/projects/stair-lights/

How about building one of these?

 

[17thman]

why would you need that for cats. In addition, a reflective layer behind the cat's retina called the tapetum reflects incoming light and bounces it back off the cones, making more use of the existing light. The tapetum is probably responsible for the fact that when a small amount of light hits a cat's eyes at night, you see shiny green orbs.

the idea od setting the sensors back, a little, in tubes is a good one

 

[ban-all-sheds]

http://alan-parekh.com/projects/stair-lights/

How about building one of these?

Quality work...