These actually are made for 12V input rather than 5V. But you could use any input voltage as long as you power them with that voltage. Some are 9V, some 12V. I have a Toshiba one somewhere that is a 24V input, and is about 15" long by 8" wide! But it takes about 4 or 5 amps, and that's way more than I want to use--my motor doesn't take much more than that while cruising at speed!
I picked these CCFL scanner lights because I had them
and because I already knew they could light up a room, or at least part of one, very well. I've used one identical to the square front one as my over-bed reading light for several years, before I ever started this crazy bike project. Even with one of it's two L_shaped bulbs broken, it puts out enough light that I have to squint a tiny bit to look straight at it from a foot away, even after staring at my 19" LCD with a mostly-white screen, when those two things are my only light sources in the room.
So I knew it would be bright enough to let me *be seen*, which was my major goal, and it'd let me see around me clearer than just a narrow-focused flashlight, at least for stuff within a few yards, which was my minor goal.
I started out using just the longer one, on the DayGlo Avenger upright bike, with a second one on the rear with some red stage gels on it for a taillight. Later I got the LEDs you see on the ends of it, installed them, along with red ones in back; they're my turn signals and marker lights for side visibility. I changed the rear one to a brake light isntead of just a taillight, after I got the red marker LEDs in there. Unfortunately CCFLs don't light up fast enough and have a few seconds warm up to get bright, so they don't make good non-steady lights.
I replaced the whole rear assembly with LEDs shortly after.
But as a headlight, they do a dang good job for close-up work, and are highly visible without being blinding, unlike LED and other types of lights--mostly because I'm not *trying* to get a focused spotlight; I'm trying to make a large-surface-area white light to make me visible from farther away, to give people more time to react to me.
Since I ride in the city, most of the places I go have decent street lighting, so I can already see what's around me well enough without a searchlight up front.
It's just the close-up stuff right next to me and right in front of my tire that I need to see better, and these do that very well.
Now, the catch is, they *are* thin glass bulbs--about like having a foot-long glass thermometer shape inside that plastic box. So they will break easier with abuse. So far, I havent' had that happen, even when I've laid down the DayGlo Avenger in skids/etc. Ripped the LEDs off the end once, but didn't break the bulb. They are generally anti-vibration mounted already, because those scanner enclosures are designed for the average consumer who is going to drop the thing at least once during it's life, because it has to be handled all the time to be used.
If you were to take bulbs out of just a regular scanner, rather than the transparency adapters that go on top of them, they might not hold up as well, because their end-mounts aren't usually designed to be as shock-absorbing. Can be fixed, but gotta be careful.
