Motion Sensor Lamp (basic Tools and Materials)

Before I begin please note: while an electrical qualification is not always required for this work (check your state/country electrical regulations), it will still be plugged into a mains power supply so you need to be careful. Ensure the insulation isn't damaged, wire is stripped neatly and screwed into terminals very well and that no bare wire is exposed anywhere.

If you're not sure about any of this stuff, consult someone who is and have them show you the ropes. It's not a difficult project, but if done wrong it could end badly.

When I was growing up my dad had motion sensors for lights around the house so I just assumed this was something you buy at the shops. It isn't. What is available here are battery powered sensors with built in lights and sensors designed for hard wiring into building power supplies for lighting and security systems. But not something you can just plug into the wall.

I asked dad and he said he'd always just made them himself and told me how they're wired.

So credit goes to him for the idea and execution! Thanks dad :)

(it's possible that this has already been done many times over, but I haven't seen it before and haven't found an off the shelf solution)

Materials:

A motion sensor intended for hard wiring to an electricity supply - mine was $15 from Bunnings (Australia)

Sacrificial extension lead ($5-$20 or lying around the house)

Tools:

Wire cutters or pliers that can cut wire

Terminal screwdriver

Knife of some kind

Optional - drill & large drill bits for modifying the plastic case of the sensor

Extension cords in Australia come with 3 wires inside them - a live, neutral and earth wire. The only ones we're going to use are the live and neutral wires so the earth can be cut off. The lamp which is being plugged into this lead only had an active and neutral wire anyway which is common for lamps (if they only have 2 pins on the plug they don't have an earth).

So first cut the extension cord where you want the sensor to be placed, have a look at where it'll be mounted and then find out how much electrical cord you'll need either side.

Then strip back the outside insulation of the extension cord - carefully run the knife around it in a circle and then bend it back and forth along the cut line until it breaks. Be careful not to cut the insulation on the wires inside. If you do, just cut the wires back and start stripping the outside insulation again, there should be plenty of cord available.

After you pull off the outside insulation, you'll be left with the 3 wires I mentioned before (live, neutral and earth). Live is brown and will connect to the live wire inside your home's electrical socket, neutral is blue and will connect to the neutral wire inside the socket and earth is green and yellow and...you guessed it, connects to the earth wire inside the socket. Strip these back with the wire cutters/pliers, leaving a cm or so of bare wire.

Do this for the other side of the cut cord as well.

CAUTION: do not mix up the live and neutral wires as if they're switched your appliance can still work, but it won't be turned off when you think it is. This is potentially dangerous.

Now open up your sensor - I don't know if they vary much from country to country, but this one has brown, blue and red wires inside it.

Brown connects to the live brown wire from the plug side of the cord.

Red connects to the live brown wire from the socket side of the cord.

Blue is where both neutral wires are connected.

The way I was taught to prepare bare wire is to twist it and then fold it over so there's plenty for the screw to grab onto. I did this for both live wires, and then twisted the neutrals together.

Then screw them in using a terminal screwdriver as tight as possible. Make sure there is no bare wire exposed outside of the plastic terminal.

Double check that you've matched up the wires correctly.

As this motion sensor was designed to be weather proof and have the electrical cords coming out of the back I had to use a drill to create space for the wires to come out vertically (hopefully you do a neater job of it...). This way it can be mounted on a flat surface and have the wires sit flush.

All there is for it now is to mount it! You can remove the back plate and screw it to a wall, cable tie to something (my step sons have one cable tied to their beds so the room lights up when they walk in), attached with mounting tape or just sitting on top of something.

Once again, this may vary on the country or brand, but this sensor has 2 dials for the time it'll stay on after detecting movement, as well as the light conditions it'll operate under.

This one goes from 5 seconds to 5 minutes on, and the lux setting is basically from bright light to darkness. It's just a matter of trial and error to get these right and they're easily tweaked.

Originally I was going to mount this on some furniture or on a piece of wood, but sitting under my monitor actually works just right. It now works like a normal extension lead, with my lamp plugged in at the socket end, but now with extra usefulness! (yes, my desk is a disaster, I have too many hobbies)

Now my lamp will stay on when I'm at the computer, and will also turn on when my partner stumbles sleepily into the office to do some writing when it's still dark but doesn't want to be blinded by the main light. It still has its inline switch so it can be turned off as normal if I don't want it triggered by motion (eg. if I'm watching a movie). My step sons' set up also has an inline switch so they can turn their lights off at night and not be blinded when they get up to go to the toilet - their setup is a bit different too as it's connected to 2 sets of LED lights that are mounted under their loft beds.

One more thing to consider - if you're using a "smart" globe I'd make sure that the time interval is dialled up a little so you don't trigger wifi pairing by accident. The lights we have try to pair when they're switched on and off quickly and start flashing so this could get annoying.

These sensors are so handy for making the lighting in your house more convenient! They can be used for garage lighting, cupboards, bedrooms, etc, etc. You can use them with existing lamps including LEDs, but there's also scope for other appliances.