One of my aquarium lights was burning through lamps a while ago, and then quit working altogether. Recently, I’ve been moving my one good light back and forth between aquariums, and looking for a new one at the pet stores, and aquarium store. Tried to get the aquarium store to order me one, and they couldn’t get the right size; ditto Amazon.
I don’t know why I was so dumb about it, but it dawned on me today that the light has a ballast in it, and given its behavior, that’s probably what went bad. So I opened it up, took the connectors off the wires going to the plug, and checked for continuity. I used two long pieces of wire to jump the fixture. Couldn’t get continuity no matter what I did, so the ballast must be shot.
I bought the light used, and I’ve had it for about 8 years. It could be 18 years old.
Anyway, I started Googling the part, and I’d just typed in ballast and the first two letters, when the whole part number came up. Amazon sells it, so since I have Prime, I ordered it there; no shipping.
New fixtures run about $40. The ballast is $14.50. Yay! I’m going to have to solder two connections, and replace six screws. It’ll be here Monday.
We had a similar deal with our pellet stove - the combustion blower wasn’t blowing. I thought we’d need to get a new one. Turns out it was just very sooty - all it needed was a good cleaning. Whew!
Yes, if the SS Poseidon had had all their fluorescent lights working, they never would have turned over. You know damn well what the trouble is – it’s that bastard Linarcos!
The ballast regulates the voltage/current that goes to the bulbs; it used to be done by a small neon bulb that was screwed into the circuit. If we’re lucky, a Doper electrician will come along and explain it better (it’s actually magic).
BTW, Lad, you must be a young’un to not know what a ballast is.
This isn’t really a big DIY project. It’s connecting six wires in such a way that you’d have to try to do it wrong. The ones coming out of the left side, you connect to the left end; the ones coming out of the right side, you connect to the right end, end the ones coming out of the bottom, you connect to the switch. I do have to strip about 1cm of the ends of the wires I cut, but that’s day 1 stuff as well.
I’m going to solder them, because I know how, and have a soldering iron and solder (flux core), but strictly speaking, I don’t have to. I could just twist them together and tape them over.
If you’ve ever lifted a fluorescent fixture at the DIY store and wondered why they’re so heavy for something that’s just flimsy sheet metal and a bit of wire, all the extra weight is from the ballast. It’s a type of transformer, which is a very dense hunk of mostly-iron. Like an old-fashioned wall-wart. Modern wall-warts aren’t transformers and are much lighter than they were in Ye Olden Dayes of, say, the 1990s.
I don’t know that “ballast” in the electronic sense is connected to its surprising weight versus the whole fixture. But it might be.
“Ballast” means “To give stability.” Ballast on a ship gives it physical stability by lowering its center of gravity. Ballast in an electric device balances the power load by serving as a regulator.
Congratulations on just needing a part. I ran into a similar thing on Friday. The router on my CNC machine just didn’t turn on. The lights were on, but nobody working. Turns out I just needed new brushes for it. So $15 instead of $120.
