Electronic Ballast
 

A fluorescent ballast for my son's aquarium blew a couple resistors. This
part is built into the cover of the aquarium so I'd rather try to replace
the blown components than the whole thing. Can anyone assist with
determining the value of the resistors so I can try replacing them? I can't
find any info using the ballast model number. The bulb is 8w.

Picture of ballast:

http://members.cox.net/4wdcivic/images/ballast.jpg

TIA! - JIM

"Jim M." writes:

A fluorescent ballast for my son's aquarium blew a couple resistors. This
part is built into the cover of the aquarium so I'd rather try to replace
the blown components than the whole thing. Can anyone assist with
determining the value of the resistors so I can try replacing them? I can't
find any info using the ballast model number. The bulb is 8w.

Picture of ballast:

http://members.cox.net/4wdcivic/images/ballast.jpg

TIA! - JIM

I bet more is blown than those resistors.

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"Jim M." wrote in message
. 6...
A fluorescent ballast for my son's aquarium blew a couple resistors. This
part is built into the cover of the aquarium so I'd rather try to replace
the blown components than the whole thing. Can anyone assist with
determining the value of the resistors so I can try replacing them? I
can't
find any info using the ballast model number. The bulb is 8w.

Picture of ballast:

http://members.cox.net/4wdcivic/images/ballast.jpg

TIA! - JIM


If you replace the resistors they'll just blow up again. I bet you'll find
both power transistors are shorted, particularly since they've used wimpy
TO-92 transistors where big TO-220 cased devices were obviously the original
design.

Personally I wouldn't even mess with it, you can get a suitable ballast
circuit board out of a compact fluorescent lamp, or you can get a nice
electronic ballast on ebay that'll work. I used a Triad ballast designed for
18W CFL's to replace the shorted chokes in my spa ozonator which has an 8W
lamp.

"Sam Goldwasser" wrote in message
...

I bet more is blown than those resistors.

They didn't burn up - they blew like fuses. That's a bad sign.
--
N

"James Sweet" wrote in
news:EpAee.4848$Vu.827@trnddc07:

you can get a suitable ballast
circuit board out of a compact fluorescent lamp, or you can get a nice
electronic ballast on ebay that'll work. I used a Triad ballast
designed for 18W CFL's to replace the shorted chokes in my spa
ozonator which has an 8W lamp.


Ok, I'll forget about trying to repair it. Should I use the ballast from a
9W CFL lamp and/or is it possible to wire two 8W bulbs in series to an 18W
ballast for double the light?

THX!

Jim

"Jim M." wrote in message
. 6...
"James Sweet" wrote in
news:EpAee.4848$Vu.827@trnddc07:

you can get a suitable ballast
circuit board out of a compact fluorescent lamp, or you can get a nice
electronic ballast on ebay that'll work. I used a Triad ballast
designed for 18W CFL's to replace the shorted chokes in my spa
ozonator which has an 8W lamp.


Ok, I'll forget about trying to repair it. Should I use the ballast from a
9W CFL lamp and/or is it possible to wire two 8W bulbs in series to an 18W
ballast for double the light?



The wattage doesn't quite work like that. Various classes of fluorescent
tubes are rated at specific currents, and the length of the tube roughly
determines the voltage across it and hence the wattage it runs at. The
rating is just nominal, you can under or overdrive them by 10-20% or more at
the expense of lifespan so it's really not too critical. There's a smaller
version of this
http://cgi.ebay.com/ws/eBayISAPI.dll...345 6886&rd=1
which turns up from time to time which would work well for you, it's
designed for 1-2 16W CFL's, that'd be ideal if you want to run either one or
two lamps. You can't just run them in series, you won't have cathode heat
and the tubes will fail soon. Either pull the ballast out of a 9W CFL, or
find something similar to what I described. If you get stuck I think I have
an extra one somewhere I'd part with.