How to power on a computer by remote control
In this project I will show how to connect a remote control module to a computer so it can be activated by RF remote control.
This is useful if the computer is in a far to reach place and therefore it isn’t easy to have access to the front panel start button. Furthermore we also have the option of disconnecting the front panel button and thus the activation will be done exclusively using the remote control, preventing anyone else from using our computer.
(The video has English captions available)
Materials used
(and where I bought them from:)
1. 2 Channel remote control kit
http://www.emimikos.gr/TEL-925N/
Alternatively, and if we want to keep costs down, we can use a single channel module.
2. QLT Power QDC1S 0512S integrated circuit
Edited 2/5/2015
http://www.acdcshop.gr/converterdcdc1wuin12vdc30mppmc100khzsil4pin75vpp-p-12505.html?page=2
The part above was incorrect! The right part: http://www.acdcshop.gr/converterdcdc1wiout83mauin5vdc002ppmdegc80khz18g-p-10212.html?page=2
Datasheet: qdc2s-2405s
Any similar IC can be used instead, or any assembled DC to DC boost converter from 5 to 12Volt, minimum power of 1 Watt or more.
3. Two small electrolytic capacitors
I used 220uF caps rated at 25Volts. We have to mind the correct polarity when installing them. Also the voltage rating must not be lower than 16 Volts.
4. A small piece of perfboard
5. Female pin strip 1 x 2, 2,54mm (0.1″)
http://www.acdcshop.gr/socketpinstripsfemalepin2straight254mm1x2len32mm-p-12019.html?page=4
6. Various wires for the connections
I used the internal wires from a length of alarm cable.
Any kind of wire can be used, for example UTP network cable, but alarm wire is thin and flexible, so it is easier to use.
Construction of the power supply (DC to DC converter)
The remote control module works with 12 Volts. But when the computer is turned off the only voltage available is 5 Volts stand-by (purple wire). For this reason we need a mini power supply to raise the voltage from 5 to 12 Volts.
I used the QLT Power QDC1S 0512S integrated circuit:
Two capacitors must be connected in parallel with the input and output respectively. The datasheet doesn’t specify type of capacitor or capacity, so I tried the circuit with two plain 220uF electrolytics and it worked fine.
This is the assembled power supply on perfboard, next to a 20 cent eurocoin for scale:
Wiring up the relays
Since these remote controls can be accidentally activated while we have them in our pocket, I connected the two relays in series. So for turning on or off the computer, both buttons on the remote control have to be pressed at the same time.
This is how I wired the relays in series:
Installing the module into the computer
I have connected the input of the DC to DC converter to the main PSU socket. I have simply stripped the ends of the wires and inserted them from the top of the socket, then secured the wires with some insulating tape. Red wire goes to 5VSB (purple), black wire goes to ground (black).
The yellow/green wire comes from the relays and I have connected it on the motherboard pins where normally the computer’s power button wire is connected.
The connector of the power button can be seen below the yellow/green wire. It is currently not connected anywhere, so the computer can be turned on exclusively by the remote control.
