DC flourescent lamp

I've never heard of a dc fluorescent lamp before...

You would have to limit the current by electronic means or by a resistor making it a waste of power.

Also the tube wouldn't last long as the electrodes would get depleted and soon burn out.

72 watts is also one heck of a powerful fluorescent tube!

John.

Check under Street Lights in any big catalogue (Sweet's Spec book probably can point you at dozens, and I remember seeing them @ grainger). Also, double check your specs, 72 vdc is a common use for highway lighting (though I can't for the liffe of me imagine why), and 120W is also a common enough spec. Don't know if I's care to work with someone who wouldn't spec in a dc/as inverter for major lighting, though. Sounds like you're working for an architect rather than an engineer. I'll pray for you

Depending upon the style of starter circuit, you might want to make sure that the starter circuit reverses the connections to the tube on a regular basis as otherwise, one end of the tube will fail very rapidly.

In the RN on DC ships in the 60's, we had someone go round and each compartment had a reversing switch to change the power + & - over each day for that very reason....I am sure that this can be or is done electronically today with very little effort.

I use small 8 watt tubes in my caravan on 12 volt DC with some sort of oscillator circuit, it does not seem to burn out one end first, but the tube's life is only a few years (with only a few months usage!).....good tubes from European manufacturers last longer and give better and more natural light !

i have never heard of dc flourescent lamp , specifications mentioned seems incorrect,

it may be 120V , 72W , or dc to ac converter that is inbuilt as a complete module .

Of course you can run fluorescents with DC, what have you got against it????

Just that in your experience it was not done, does not mean that it cannot be done.....

Believe me, a great many DC ships in this world use(d) it just in this fashion.

Think of it this way...

you purchase a Fluro that runs from DC, So you have a fluro lamp that runs from DC, you don't know about the little black (or mine is silver) box inside that does the DC-AC conversion, so your oblivious to how it runs, some think of it as "I don't care how it works, it just does"..

So are the specifications so far incorrect, or they are correct as far as the knowledge of the poster?

I would just like to mention that with 220volt DC, there is no need from the point of view of lighting a fluorescent tube to have an oscillator or any "electronics" so to say, but as I mentioned before, you need to change the tube polarity each day to ease the wear on one end of the tube and therefore prolong its life....we had 1000s of them in the RN in the 50s & 60s, especially on 220v DC Aircraft Carriers and older DC ships built (or designed) before NATO took over.....

You might want to explore some of the marine "yacht" lighting web sights.

Here is a place to start.

http://www.yachtlights.com/cat--Fluorescent-Fixtures--fluorescents

Mike

120VDC --- why DC?

DC is easier to store than AC?

The trains (the last I knew) in Mt Isa Mines were electric, DC, they ran from batteries, and I think it was 120V, I worked for a company (previous to now) that made the linear DC 400A & 600A regulators for each train.

Ah yes that is true, and there are various, other, applications using similar systems.

--- I was really asking so the guest (original poster) might enlighten us with the application he wishes to use the type of lighting he/she referred to. Maybe there is something better that the guest is not aware of and another member might just give that information.

It is always helpful when related information to the question is available for the folks here to evaluate and determine what help the questioner needs.

For example: So far we have answers related to mine trains, aircraft carriers, street lights, and who knows what will follow --- it should be interesting.

By the way the guest has not submitted another post to clarify his/her needs.