"Free" ballasts and adjustable ODNO for smaller bulbs

[DarkCobra]

I've been playing with some ideas inspired by discussions on this forum. Maybe these will inspire you too.

"Free" ballasts for smaller fluorescent bulbs:

I recently had a household 14W fluorescent spiral burn out. Curiousity got the better of me, so with careful use of a hacksaw I extracted the electronics intact. Quite impressive what they manage to pack in there, it even had a fuse! The spiral bulb had four wires. So did the F15T8 I have in my kitchen fixture. F15T8 aquarium lamps are widely available and useful in smaller tanks. Hmm

With a few connections, I had it up and running. It worked perfectly.

Two days ago, a 23W fluorescent spiral died. Out comes the hacksaw... I hooked it up to the F15T8 for a noticeable increase in brightness. Free 1.5X ODNO ballast!

I will be saving all my burnt-out household bulbs from now on.

"Free" adjustable ODNO:

Yesterday I was at "Home Labyrinth", and I noticed a three-way fluorescent spiral bulb for $8. Runs at 15W/23W/32W. With two switches, this would let you run a F15T8 at normal brightness, or 1.5X/2X ODNO.

Adjustable ODNO is a pretty appealing concept. I don't think I have the patience to wait for one (or more) to burn out in normal use, so this wouldn't exactly be free though

-DarkCobra

Edit: Oops, forgot some safety notes. If you try this, remember you're working with bare electronics. The capacitors in the ballast module can hold a charge for hours, or even days, after being unplugged. Be safe and discharge them, or handle the module and all tools which might touch it with nonconductive rubber gloves. Also, these ballasts will need to be placed in an enclosure. Preferably a waterproofed one. I may experiment later to see if one of these can be sealed in potting compound, epoxy, or paraffin without overheating.

[Oqsy]

fantastic idea! i'd been curious about the ballasts inside those bulbs, but never got around to opening one up. of course you'll need to post some pictures and/or diagrams to show the rest of us how you wired the sucker up

Oqsy

[DarkCobra]

Show me the pictures, eh? That I can do.

Hook up is actually pretty self-explanatory once you've disassembled and seen one of these.

Here's the removed 23W ballast, from a LightWiz lamp. The wires were already attached, I salvaged as much length as I could:



The top two wires go to AC. Each pair of wires on the bottom go to a pair of pins on each end of the fluorescent bulb. The black sleeve on the left AC wire conceals a fuse.

For test connections, I used 4x 1' wires with small insulated spring-loaded hooks on each end, and a line cord with insulated alligator clips on the end. (Yes, I have these kinds of things laying around )

Those with a keen eye will see I've written on the board. Since the casing is gone, I thought it wise to write the wattage on there for later reference. Also, I tested and wrote the operating frequency, 35khz.

I didn't fully disassemble the 14W ballast made by Commercial Electric. The construction was slightly different (and visibly cheaper) than the 23W:



The board-to-bulb connections protrude above the board about 1/4". I bent them outwards for easier access. The ends are marked with a red dot in the photo. This ballast's frequency continuously wandered from 37khz-59khz. I suspect it has a partial component failure - but it doesn't seem to affect the light output.

Let's see some photons. This is 1.5X ODNO, 23W into a 15W GE F15T8-PL/AQ (grow light), with flash on:



And again, with no flash, but with bright room lights and daylight coming in the windows - a rather poor attempt to represent the brightness, but it may give you a general idea:



Experiments I'd like to try, and the anticipated result in parenthesis:

1) Can the ballasts be encapsulated in potting compound/epoxy/paraffin without overheating? (Probably - not much heat)
2) Can they drive two-pin bulbs? (Most likely, just a matter of figuring out which wire out of each pair to use, or if the wires need to be joined)
3) Can they be modified/heatsinked for greater power? (Since they don't get very hot, I think this is possible, not sure it's worth the effort though)
4) Can the output of two be combined for greater power? (Not directly, each will operate at a different frequency and the AC will cancel out. Might be possible to rectify the output of each to DC, then combine - not sure what effect this will have on bulb efficiency or lifetime)

-DarkCobra

[Oqsy]

this is exactly the kind of post that keeps me coming back to this board. FANTASTIC illustrations and explanation! I have a couple of 26 watt screw-ins in my current hood, but I'm not ecstatic about the poor spread of light through the front portion of the tank. running each of those ballasts to a separate bulb would do wonders for the appearance of my tank. I just hope the brand that I have are as straightforward as yours. I also wonder about using these to OD small (13w) power compacts in something like a 10g or smaller. you could really light up a nano tank with a couple of 23-26w ballasts and a couple of 13w pc bulbs.
Thanks for a great idea!
Oqsy

[creepingdeath086]

i didnt even realize they had a balast, when the light i have dies, its getting the hacksaw too, thanks for posting this, that is really cool, what do you do for a living?

[DarkCobra]

Thanks for the kind words. I'm just folllowing the lead of the other greats here. It really wasn't until I found this forum that I believed "yes, I *will* succeed in having a planted tank!"

I have similar goals in mind as you. My 10 gallon planted tank uses two 23W screw-in fluorescents in a standard incandescent hood. This hood is an ancient one in a style apparently no longer made - it's unusually roomy, and made to be placed in the front of the tank, but can be slid back to the middle. This works out very well in terms of light distribution.

Now I want to convert my 2nd 10 gallon to planted, and since its modern hood isn't so versatile, I want to build one. Two or three F15T8 18" bulbs would provide uniform light distribution, better efficiency (much less restrike than spirals), and if driven by three-way ballasts, let me crank up or turn down the light as desired.

-DarkCobra

[Oqsy]

independent confirmation...

i was so interested in giving this a shot that I went ahead and opened some pretty old 19w jobs from HD (commercial electric). I have 2 15w fixtures over my malawi mbuna tank, and since there are no plants and the fish are from deeper waters, I've never really sought after a lot of light on that tank. However, the fixtures are both cheapo magnetic ballast "comes with the tank kit" strip lights. I've noticed that they hum extremely loud (i can hear it over the splashing of the bio wheels in the emperor 400 less than 6 inches away). So I decided this was the perfect application for a very slightly overdriven set of 15w bulbs on electronic ballasts. the bulbs I had were identical in circuitry to the 14w commercial electric in the diagram. it took a little work to get the bulb leads connected, and I would have preferred the insulated wires of the other bulb shown, but I digress. The bulbs were relatively easy to open (took a pipe wrench and gradually increased the pressure until it started to pop a bit. that was enough to loosen the glue and they opened right up with no damage to the electronics. clipped the wires from the bulb and the ac line and wired it up in less that 5 minutes. plugged it in, and with only a 5w increase in power, I could still tell it was brighter. it's no 4x OD, but it works perfectly for my setup. The more important thing, NO hum at all. crisp light, no hum, and INSTANT START! no more flickering for 10 seconds before they start. highly recommended mod if you have the right application and the right tools.

Oqsy

[DarkCobra]

Originally Posted by creepingdeath086

i didnt even realize they had a balast, when the light i have dies, its getting the hacksaw too, thanks for posting this, that is really cool, what do you do for a living?

Yeah, it's amazing what's considered disposable nowadays.

I do computer programming, networking, construction and repair for a living. Electronics is one of my hobbies.

-DarkCobra

[DarkCobra]

Originally Posted by Oqsy

independent confirmation...

Awesome!

Make sure there's no chance water or condensation can contact the ballast. One of my first spiral lights in aquarium use died violently after a few months - apparently as a result of condensation collecting in the hood, dripping onto the bulb casing, and seeping in through the seams. I came home to a room full of chemical smoke and a faint crackling noise - not to mention some VERY terrified cats. Ballast autopsy showed fire/arc damage, and corrosion indicating water had been in there a while. I'm lucky the damage ended with the bulb.

Since then I seal every seam, ventilation hole, and anything else water might leak into on a bulb with silicone prior to aquarium use. No further problems in several years.

-DarkCobra

[Oqsy]

yep, they're very well protected, in fact moreso than the magnetics that preceded them. my wife was pleasantly surprised at the lack of hum and ease of switching them on and off this evening when i showed her the new trick.

[Opiesilver]

Originally Posted by DarkCobra

I do computer programming, networking, construction and repair for a living. Electronics is one of my hobbies.

-DarkCobra

You're a BOFH!! Always tinkering huh? I've just got to try this one now.

[DarkCobra]

Originally Posted by Opiesilver

You're a BOFH!! Always tinkering huh? I've just got to try this one now.

Yes, I am. Pardon me while I glue 60-grit sandpaper in some unsuspecting luser's DVD burner...

Oh, and let me know how it goes if you try it.

-DarkCobra

[Opiesilver]

I was thinking maybe you could just wire that up to the door knob of the computer room myself. LOL!!

[compulsion]

damnit and i just thrown one away, this would be good for my mums smaller tank with her 15W.. i have a 23W compact left over when it dies.. ill also do this, ive been wondering whats in them and i thought it would be to small to be magnetic. thanks for the useful and ingenious idea. this will be great for people running nanos and smaller tanks.. i rekon there pretty similar to a cold cathode ballast by the looks of things. indeed very much the same size

[Oqsy]

darkcobra just pm'd me a follow up question on how my cfl ballasts were holding up... here's my response, many months after installing them for anyone that's interested in the longer term viability of this trick.

Originally Posted by Oqsy

I just took that fixture down 2 weeks ago, and not because of any problems, but because I was switching that tank to a new fixture that's housing a 2x55w AHS kit. Those lights with the ballasts still work like a charm, and took care of the awful humming that was coming from that tank

yep, those lights are actually for sale with my 29g setup that's posted in the swap/shop section. I'm considering trying this on some tiny NO t5's from the hardware store for a nano hood for my desktop shrimp vase (search the nanos forum for that experiment if it ever happens) Thanks again DarkCobra for the great idea.

Oqsy