48V DC DC BALLAST FOR FLUORESCENT LAMP 20W

Use an invertor, or a cheap UPS.

John.

Try looking at railway-oriented sites for 48V DC - 110V DC inverters: it is often used in locomotive and signalling installations, I believe. Google inverter railway 48 110, or something similar, such as converter - I got a lot of hits there. You can also try some of the suppliers on GlobalSpec!

Many new electronic ballasts convert AC power to DC and then generate high frequency AC power to operate a fluorescent lamp. I like to think of a fluorescent as a bi-polar DC device because it will operate on AC or DC as long as it is current limited. The problem with DC operation is that after an hour in a horizontal fixture, the mercury migrates toward one end of the lamp, leaving the other end dark. AC power prevents migration. High frequency allows for physically small components. There are lots of ballast designs out there. If you find one that used something close to 48 volts DC then you could bypass the conversion to 110/220VAC. Check out some of the Integrated Circuit manufacturers for electronic ballast chips. The normal voltage drop across a 20 watt fluorescent lamp (depending on the type) should be about 45 to 55 volts. That makes for a nice fit for your power source!