Turn Your PC on With a Car Remote Fob!




About: I build stuff because it isn't available to buy, or is too expensive, or the ones you can buy don't do what I want them to. Sometimes I don't have a reason, I just want to build something. For me it's about...

Just for fun:

My computer is an arduous 2.2m from my sofa. I bet I waste a load of energy turning it on:

This paper (http://large.stanford.edu/courses/2011/ph240/maher...) from Stanford University suggests humans consume about 967W whilest long distance running at an average 10.1 km/h.

Assuming I used all 967W to accelerate my lumbering 70kg body from 0-10.1km/h.


Work = Force x Distance,

Force = 439.55N

Acceleration = Force/Mass

Acceleration = 6.27929m/s^2

Assuming the trip is 50% acceleration, 50% deceleration, we hit a top speed of 3.71m/s Using SUVAT equations. And that takes 0.59 seconds. Double that for the full trip, double it again for the return. This gives a total of 2.37 seconds. 967W at 2.37s gives a total energy expenditure of 2291.79 Joules!

Measuring my unit, is pulls a staggering 0.6w of power. So that's eating my energy to turn it on every 3820 ish seconds, or just over an hour... It pulls 12W whilst you press the button too... Bugger... So this isn't going to save the planet... But it will save my slothdom! Let's put a remote start on that thing. Here we go!

Step 1: What You're Going to Need...

  1. RF key fob relay like this:
    1. https://www.amazon.co.uk/JIUWU-Wireless-Control-Ch...
    2. https://www.amazon.co.uk/dp/B01A6VO79M?psc=1
  2. Basic electrical tools including a soldering iron.
  3. A spare PC fan power extension cable.
  4. 12V DC power pigtails:
    1. https://www.amazon.co.uk/5-5mmx2-1mm-Power-Pigtail...

Step 2: Wire It Up

  1. Chop your fan connector in half, and strip the wires
  2. Tin the ends
  3. Attach extension cables
  4. Wire extension cables into output side of the relay
  5. Wire pigtail into the input power

Step 3: Put It in the Computer

  1. Unplug the power switch from your mobo.
  2. Plug in the fan plug
  3. Plug the power switch from the front panel into the other side of the fan extender
  4. Pass the 12V DC jack out of the computer.

Step 4: Done! Test It Out.

Mines been working for about four years without changing the batteries. Works a treat!



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    4 Discussions


    1 year ago

    very nice solution! exactly what i was looking for. build it today for my pc and can now control the system with broadlink rm pro, rm plugin and amazon echo without dealing with the hole WOL, Windows Update and unified remote struggle!



    2 years ago

    Does the 12 V female power cable connect to a wall outlet charger, or could I hook it up to a male connector hooked up to a battery pack?

    1 reply

    Reply 2 years ago

    Either way would work. Thinking about it, you could have an internal rechargeable battery that recharges every time you power on your PC: Smart! I have an abundance of sockets so a wall adapter works for me.