USB Powered Xmas Lights

  01chris 18:32 30 Apr 2006

I have a set of christmas rope lights which have LED's in them. It is powered from the mains but would I be able to power it from my USB port? I WOULD take the LED's out and put a few of them on a normal USB cable but I want the little box on the end of the lights which controls the flashing patterns.

Basically would I be able to power a set of christmas lights from USB? Am I right in thinking USB is DC and mains power is AC, does this matter?

Hope that make sense

  SANTOS7 18:37 30 Apr 2006

click here=
might be better to buy dedicated light systems.........

  rmcqua 19:30 30 Apr 2006

The USB ports in a PC can typically provide up to about 500mA total at 5V DC. This would be OK to power a few LEDs, but you would need a series resistor in line with each. Assuming an LED that draws around 20mA, the value of each series resistor would need to be around 150 Ohms.
I would doubt that the "little box that controls the flashing patterns" operates from 5V (check the mains power supply output rating), in which case I think you are stuck with SANTOS7's suggestion.
Please forgive me if I am wrong, but I am guessing that you are not an electronic engineer, in which case I would not recommend trying to use the USB ports as a power source.

  Fruit Bat /\0/\ 19:30 30 Apr 2006

Leds are DC you will have a mains adapor to change the AC 240V to an much lower DC voltage

a USB port will only power upto 500mA thats not many lamps. If you blow the fuse in the USB port thats it port us forever,

  Totally-braindead 19:46 30 Apr 2006

Agree with the others its really not a good idea, too many problems and theres a good chance of destroying your USB. click here they do Xmas trees powered by USB - little ones but only nearer Xmas. If you want something silly or whatever then how about this click here

  €dstowe 20:32 30 Apr 2006

Is your next trick going to be attaching a hard drive, keyboard and mouse to your Christmas tree?

  01chris 22:28 30 Apr 2006

Ok thanks everyone. No I'm not an electrical engineer, I'm a 14 year old kid who likes messing around with stuff like this!

Oh well, I just wanted to make my old Imac look cool.

Thanks anyway

  01chris 22:30 30 Apr 2006

PS. I dont want to use Cold Cathode lights or anything like that before anyone suggests them, I was just trying to use up old bits and bobs I had lying around.

  01chris 22:36 30 Apr 2006

Oh, and do I presume that, for the same reasons, Firewire isn't an option either?

  Stuartli 23:30 30 Apr 2006


Don't play around with electrical goods, no matter what they are, if you don't know what you are doing.

Remember, you can't see electricity coming and if you get it wrong it can/could seriously injure or prove lethal.

  €dstowe 06:56 01 May 2006

If you do want to mess around with electronics "gubbins", have a look at Maplin click here who do a whole host of stuff which fits in with what you say you're interested in.

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