[anonymous200912]

Hey, can someone send me a link or tell me what hardware i'm after. Basically I went IKEA today and they had some cupboards with tiny sensors in them which turned LED's on when they are opened...

I believe these are PIR Sensors, but all I can find on the internet are the large ones you have for alarms, where can I buy the sensor which is small and easily hidden?

[SOSA_]

Pretty simple circuit. Let's assume your cupboard is about 70cm long. Get an IR light and an IR reciever. Next get an AA battery clasp, some circuit board, 330 ohm resistors and a couple LED's.

Easiest way to do this is set it up in series. So it would go something like
Battery
Resistor
IR light combo
LED
Negative end battery

I forgot to mention, set it up so that the IR light and receiver are on 2 seperate panels

[anonymous200912]

This setup just had the one sensor though, I would prefer that really.

[thisshitisannoying]

There's a lot of ways you could do this. The easiest thing I can think of is to just get a normally closed switch, put it up against the cabinet door, when you open the cabinet door the switch closes and electricity flows to the LEDs. I did this before in an old vehicle that had no light in the glove box. Keep in mind you'll be able to see the switches so if it's for something you want to look really nice maybe stick with the sensors.

[SOSA_]

This setup just had the one sensor though, I would prefer that really.

I wouldn't know how to do that. Sorry man.

[thisshitisannoying]

A simple search on ebay for "mini pir motion sensor" returns a lot of good results. You can find them for less than $3.
You will have 3 pins on the sensor, Voltage In, Output, and Ground.
Parallax also sells a mini PIR module for $9.99 they have good quality products, you get what you pay for.