reusing scanner lamp w/o heavy duty adapter?

I've been trying to do something similar to these


I want the lamp to work without a heavy duty ac to dc adapter, but it looks like there's no practical power cord that has low enough voltage. I've tried using a basic voltage converter ( http://www.amazon.com/VX-79NP-MULTI-PURPOSE-CONVERTER-MULTIPLE/dp/B0014JUGTQ/ref=sr_1_20?ie=UTF8&s=electronics&qid=1209273618&sr=1-20 ) set at 12 volts, but the bulbs don't light.

Does anyone know if there's a way to do this without the giant adapter, or if there's a way to light the bulbs using a USB connection? I've looked online, and the only thing I've seen is this: http://www.danielandrade.net/2005/12/27/howto-using-the-scanner-light-inside-your-computer/ but they're using a male molex connection. I'm just looking for a plug that's a little more practical: an electrical outlet being my first choice, a usb port being my second.


seebrown (author) 9 years ago
I think I figured out what was wrong. I actually had two sets of bulbs. One wasn't working at all, and I think they were burned out. The others worked with a 9volt battery, so I'm going to modify my design to work with the battery. Thanks so much you guys!
seebrown (author) 9 years ago
I just read the wires, and they are 15VDC. I basically have no equipment to give any sort of reading on voltage, and since this is probably a one-time project, I'd rather not have to purchase anything for it. Would I need double voltage to light both lamps? Is there any way to do this without using a regulator? Maybe the battery is the best solution (although if it needs 15 volts or more I don't think that would work since the 12 volt adaptor didn't work).
I have done this before, just on batteries. I managed to get a 12 volt lamp to light at 9 volts. Anyway, all I did to test twelve volts was take any old 12 volt adapter and connect it to the transformer of the lamp. Lit right up. Maybe your lamp is really picky, and like NachoMahma said, maybe you need mor voltage. Try a 24 volt adapter connected to a variable voltage regulator. Set it to it's lowest setting, slowwly go up until it lights, and make it permanent.
NachoMahma9 years ago
. Are you trying to power a unit similar to the one shown in step 11 of your first link? Judging by the other links you provided, most of those units run on 15VDC, not 12.