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In this instructable I'll show you how to turn an old cellphone into a remote power switch for your Computer.
This is nearly free, if you have an old cellphone and a SIM-Card.
What you'll need:
- Mobile Phone
- Photoelectric sensor (found in many devices) or opto-isolator
- A little wire
- Solder iron
The Scematic is very easy.
You take the vibration-alert power to power a LED, that LED makes a photo sensor conductive, which is the same as you press a button. So you put the photo sensor paralell to the "normal" power switch.
I tried to use a transistor first, but it turned out, that it is way harder that the resistance is big enough if the telephone doesn't ring, but is low enough to turn on the computer if it does. So I used the photo sensor.
This is nearly free, if you have an old cellphone and a SIM-Card.
What you'll need:
- Mobile Phone
- Photoelectric sensor (found in many devices) or opto-isolator
- A little wire
- Solder iron
The Scematic is very easy.
You take the vibration-alert power to power a LED, that LED makes a photo sensor conductive, which is the same as you press a button. So you put the photo sensor paralell to the "normal" power switch.
I tried to use a transistor first, but it turned out, that it is way harder that the resistance is big enough if the telephone doesn't ring, but is low enough to turn on the computer if it does. So I used the photo sensor.
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We first apply the wires for the light sensor.
Many computers have something like the thing shown in the image on the mainboard. If yours does, just solder your wires to the PWR/POWER SW/POWER (or similar) and the GRD/GROUND/(-) (or similar) pin.
If your computer doesn't have somthing like that, you can direkly solder to the main board (you'll lose guarantee and you can damage your computer) or you can rip of the isolation of the wires from the normal power switch and solder it there. If you want to be very careful you can also use needles, solder this wire to them an put them into the cables from the switch.
You can test your setup: If you put together the end of the wire, the computer should boot. If it doesn't contact me.
Many computers have something like the thing shown in the image on the mainboard. If yours does, just solder your wires to the PWR/POWER SW/POWER (or similar) and the GRD/GROUND/(-) (or similar) pin.
If your computer doesn't have somthing like that, you can direkly solder to the main board (you'll lose guarantee and you can damage your computer) or you can rip of the isolation of the wires from the normal power switch and solder it there. If you want to be very careful you can also use needles, solder this wire to them an put them into the cables from the switch.
You can test your setup: If you put together the end of the wire, the computer should boot. If it doesn't contact me.
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But it worked and because the volatage of the charger was a little higher then 5.0V. Another point ist, that it only charges if the computer is turned on. An old bat like in this phone doesn't last that long (for Holidays or whatever).
So I decided to let it as it is.