[Collins] 872a Lamp, revisited

[ah7i@atl.org]

I know this.

Is my English that bad or are you guys dropping context?

THAT'S why I suggested the ballast in the first place.

The only reason one mght need a little R is if the drop across the
Hg rectifier tube is lower than the drop across the flourescent tube
for which the ballast is configured. If this is the case, the ballast
will overheat.

I build a lot of stuff and if the goal is ot light the tube with
minimal effort...
It's a hell of a lot easier to add a current limiting resistor than to
go out and find enough additional L to add to a scrounged Hg lamp
ballast than it is to add a resistor....

The 872A has a 15V drop for 1,5A or so (it's rated) continous current
So as a lamp, it's a 20-25 Watter. The ionization path is shorter
than a typical flourescent lamp which operates with a drop of about
30V. So your best bet for efficiency is to run two of them in series...
with a common surplus 40-50W ballast. If you only have one tube I suggest
a resistor in series to limit the current. A cap might work as well...

-Bob
ah7i


On Sun, 31 Aug 2003, Dr. Gerald N. Johnson, electrical engineer wrote:

> BUT the ballast doesn't do it with R, it does it with L and magnetic
> saturation, not with R. Otherwise the efficiency of the fluorescent lamp
> system would be too poor.
>
> 73, Jerry, K0CQ
>