I was wondering how I would configure some sort of setup to get lights like this turn on a timer once activated by a motion sensor. I want them to turn on for about 15 seconds and then turn off once tripped by a motion sensor but I have no engineering experience and I don't know where to start. One of my friends told me I would need to configure an Arduino board setup causing it to shut off power to the lamps after 15s but after extensive research, I'm not even sure that's possible. Is there any way to pull this task off?

  • $\begingroup$ I don't know enough to answer the question. What I do know, though, is that an Arduino would work, but depending on the lamp's power you will need a secondary circuit to control the load for the lamp since Arduino isn't a high power solution. Using LEDs might curb that issue. You'll need some electrical engineering... $\endgroup$
    – Batman
    Jan 13, 2019 at 5:29
  • 2
    $\begingroup$ If you want this as a project then fine, if not these exist already as units to add to existing lights with a timer duration.. $\endgroup$
    – Solar Mike
    Jan 13, 2019 at 5:59
  • $\begingroup$ These exist? Where can I buy them and what are they called? $\endgroup$ Jan 13, 2019 at 7:08
  • $\begingroup$ @aadityak_968, they are called motion sensors and are built into the housing of a light fixture intended for use on the outside of your house, so if somebody walks up to your front door it will turn on the porch light. do-it-yourself hardware stores sell them. $\endgroup$ Jan 13, 2019 at 7:41
  • $\begingroup$ I found a motion sensor amazon.com/Westek-MLC4BC-Motion-Activated-Control/dp/B009KSEE4G/…. Are you guys saying if I plug the lamp into this and it detects motion, it will switch it on and off? Also how will I control the timer and stuff? $\endgroup$ Jan 13, 2019 at 8:02

2 Answers 2


Use standard PIR sensor for common motion-activated spotlights, like these:

enter image description here

Open it, and find the relay inside (it will usually be the bulkiest part, likely colored blue). Disconnect the output from the "NO" (Normally Open) pin and connect it to "NC" (Normally Closed) (you may need to cut a path and draw a wire to the pin). That reverses the PIR sensor operation; it switches the light off when it would switch it on normally. Then just use the 'timer' dial on the sensor to make it deactivate (and switch the light on) 15 seconds after motion stops.

It's quite possible you may find PIR sensors on the market that expose the NC contact alongside with the NO one, which would make the task even easier. Or if you don't want to modify the device, use its output to power another relay, and use the NO contact of that relay to control the light.


Here's a product that does what you want:

  • Socket outlet to plug your light into
  • Timer settable to 10s - 4 minutes

I'm sure they'll exist with other country's plugs on them.

enter image description here



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