First I want to say that this is my first instructable and I didn't take many photos.
also I got the idea from: USB controlled mini lava lamps by jamesh
this is a device that turns lights (or what ever) on with the push of the caps num or scroll lock
if you want you can use an xbox DVD remote with your computer and turn on your lights with that. so you can walk in to the room and push a button on the remote and the lights turn on
Waning. this instructable involves working with high voltage mains power, I take no responsibility if things go wrong.
Remove these ads by
Signing UpStep 1: Get the parts
3 transistor BD140
3 capacitors 10-60uf
3 resistors (so the LEDs don't burn out. unfortunately I forgot there value)
3 relays (the ones with 5 legs)
3 switches (single pole double throw) 240v (120 in the US)
1 (single pole single throw) switch 240v (120 in the US)
a box
wire
4 grommets
A keyboard with num caps and scroll lock lights
3 LEDs
7 (or more) meter extension lead
2 power sockets (see picture)
optional:
xbox dvd remote
USB cable
small blank circuit board










































Visit Our Store »
Go Pro Today »




Therefore, the value of the resistance is dependent on the wattage of your LED.
Example - 1/4W LED. 5V - 330ohms 9V - 680ohms 12V - 1kohm 24V - 2k2ohm
Look up Ohm's Law on Google if your voltage/wattage combination isn't listed.
HTH
By the way, can you do this without using a keyboard?
I mean just controlling the power switch turn them on and off just using programs on the PC. No manual intervention needed... Via USB connection...
Originally I plan to connect it to a main switch but dont know if it can be possible for very hign voltage...
http://en.wikipedia.org/wiki/Solid_state_relay
easier methinks
My design is different though.
different ways to the same end is what instructables is all about !!!