Followups set to sci.engr.lighting.
In sci.engr.lighting Steve said:
Does anyone know where I could find a 12V ballast for a F8T5
fluorescent lamp?
These guys have some, but the smallest one they list is for a single
lamp of 15 to 22 W, bigger than the 8 W tube you have:
http://www.powerstream.com/ballast-1.htm
This place has them from a couple of different vendors, and they go
down to the 8 W range you need:
http://www.solarseller.com/12___24_...cent_ballasts__lit__light_it_technologies.htm
Standard disclaimers apply; I don't get money or other consideration
from any companies mentioned.
I have a scanner where the main board has quit powering one of the
lamps.
A couple of thoughts:
The built-in ballast may be running the lamp harder than an off-the-
shelf ballast would to get more light, or maybe a little bit differently
than an off-the-shelf inverter would to get a slightly different color
from the lamp. (Other people here in sci.engr.lighting will know more
about this second point than I do.) The test for this would be to scan
the same photo on a working scanner and then on a scanner with the
replacement ballast and see how well the colors match. Even if this
happens, it might be possible to fix the color changes in software.
The built-in ballast may have some kind of status reporting back to the
main microcontroller, such that the scanner will refuse to work if it
thinks the lamp is not there. The test for this is maybe to remove the
lamp from an otherwise working scanner and try to do a scan, maybe with
a flashlight or some other light source where the original lamp was. If
the scanner works but produces a dark or dim picture, then OK. If the
scanner refuses to even start, you'll have to figure out how to fool it
into thinking that the lamp is still there.
At the prices you cited, IMHO it's worth taking a little time to play
with it to see if you can come up with a workable way to replace the
built-in ballast.
Matt Roberds