Author Topic: 12v CFLs all burned out at once  (Read 11487 times)

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Titantornado

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12v CFLs all burned out at once
« on: December 16, 2010, 11:36:07 AM »
Hello everyone!   It's been a long while since I've been on the board, but now I have a dilemma that I think only the Otherpower gurus can help with.

Since my last visits to this board, I had purchased land to build my off-grid home.  But before building that home, I required an (off-grid) base of operations.  That came in the form of a badly water-damaged travel trailer that I have rebuilt and modified for 4-seasons use.  In the course of reconstructing just about every possible thing, I decided to replace all the light fixtures, with their power hungry #921 style bulbs. (18w/bulb)    I installed 120v fixtures, simply wired to the 12v, and installed a mix of 12v medium base LED and CFL lamps throughout, with the CFLs doing the major portion of the lumens production.

All was working good, as I now manage to still produce 96% of the total lumens of the original lighting, while slashing power consumption by 69%.  The problem came when I decided to hook up to 120v "park power" to run the furnace and not suck the battery down.  The trailer has a built in electrical distribution panel for both 120v and a charger/12v distribution bank.  All the CFLs burned out in about 2 seconds when I applied power to the rig.   I'm assuming the increased voltage from the charger was the culprit. I haven't yet checked the actual voltage at the light sockets to see what it is, but I'm going to gamble a guess it will be something like 14.0~14.5 volts. (just going by the sound of the fan speed increase of the furnace blower)  All the LED lighting continues to work flawlessly. (not entirely surprising, as I believe most are rated 10~30 VDC)

Now, maybe the solution is as simple as using a different (more expensive?) brand CFL.  What I had was Feit Electric brand.  I heard the Camco brand is complete junk.  If anyone found CFLs with a more tolerable voltage range, irregardless of price, please let me know.    If not, I was kicking around installing individual voltage regulators in each fixture, but I haven't found one that would suit my purpose.  The problem I'm having is finding a regulator that has a steady output of 12 volt when the input is 12 or more.  What I found will work OK if the input voltage is 14.5, but the output drops too low when the input is just 12.5

I know what some of you are thinking.  Why worry about park power, when I'll be off-grid anyhow.  My concern comes when the solar array is charging the battery bank, likely increasing voltage throughout the rig.  Also, the possibility of running a generator to recharge the batteries for those cloudy/stormy days.

Anyhow, if you got this far, thanks for reading through my ramblings!  My fingers are crossed someone might have a solution!

Rover

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Re: 12v CFLs all burned out at once
« Reply #1 on: December 16, 2010, 12:35:12 PM »

Hi Titantornado,

As an alternative, you could use a buck/boost controller set to ~13 v to regulate your lighting load.
Rover
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ghurd

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Re: 12v CFLs all burned out at once
« Reply #2 on: December 16, 2010, 12:51:39 PM »
Nice to see you back!

Well...  I know what blew my stuff up on park power 30-some years ago!

First.
The 120VAC runs through a big "12V" transformer.  Then that's it.
Meaning the first round of my blown up stuff was because it was getting '12V AC'.
Sounds simple enough.  A bridge?

Leading to round 2.
A bridge?  Wrong.
The output voltage is dependant on the load.  Loaded pretty heavy the transformer put out 12V AC.
Loaded lightly it was more like 18V AC.
After rectified to DC, the DC output was around 24V DC.  Actually pulsating 24V DC.
That blew up a bunch of stuff too.

Any decent LED bulb will have a reverse protection diode and should be OK with the pulating DC.  
The "12V" eBay LED stuff may will the diode but tends to be over driven anyway, so they may not last too long.  
The type listing the input voltage as 10~30VDC probably has a switching regulator and it will be perfectly happy with the higher avearge voltage.
Many LED bulbs are rated for 12V DC and 12V AC, but most of them (all I ever saw?) have simple internal circuitry (bridge, cap, resistor) that will not like the higher voltage of the under loaded transformer.

The higher current incandescent bulbs had some voltage drop in the long small power wires, which act almost like a ballast resistor in a way. Win-Win.
The CFLs don't have nearly as much, and the LEDs have nearly none, so their voltage at the end will be higher too.  Lose-Lose.

Solutions.

1A-  Big giant bridge and heat sink on the transformer, and low drop out 7814 and caps for each bulb.
1B-  Small bridge,low drop out 7814 and caps for each bulb.

2-  Buy a 20A battery charger.
Plug it into the park power, connect it to the battery, leave the transformer switch (Park/Battery) set to battery.

I would do #2.  If you are running a gas genny for a larger load, can plug the battery charger into the genny to put some extra 'umph' into the battery.
And I would buy a 'dumb charger' instead of a 'smart charger'.  Some smart chargers have issues when run from small or cheap gas gennys.


A couple other hints.  Conserve conserve conserve.  You knew that.

Change the bath and furnace fans to something more efficient.  Some of those things can pull like 8 or 10A.
Homebrew higher voltage PMDC motors, or muffin fans?  The furnace will need a very high CFM and it would be best to do some research before fiddling with the furnace fan, but it would be worth it.

Any "12V lighter plug car chargers" for cell phones or AAs or USB equipment should be rated for 12~24V input on the package, and usually a small sticker or fine print rating of 10~30VDC.  They have switching regulators (usually MC34063) built in which can make them much more efficient and less prone to blow up with over-voltage.
eBay sells them Buy Now for 99 cents delivered now, if you find the right search term, which I can't right now.  Usually have to look at the closeup image to see if the sticker says 10~30V input, because they advertise them as 12V or automotive.  The last USB I saw was white with a pink backgrond, 99 cents free S&H, but I can't find it again.
EDIT-  Found one! ebay #270596738509.  Enlarge the image to see "Input DC 12V-24V".

G-
« Last Edit: December 16, 2010, 01:01:22 PM by ghurd »
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Titantornado

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Re: 12v CFLs all burned out at once
« Reply #3 on: December 16, 2010, 03:40:16 PM »
Good information there.  I suspect I'll find those wild voltages when I check.

Yes, I like solution #2 also.  While I don't have a switch for the transformer, it wouldn't take much for me to figure out how to equip it with one.

Another idea (which may or may not be good) that just came to mind from my ultralight flying days, was using a regulator typical for the 2-stoke lighting coil outputs.  Tied to the output side of the transformer, however it's only rated 16A, and I believe the transformer is rated 45A. I suppose I could just tie it to the lighting circuits with a bit of effort.

As with conservation, yea, I know that furnace fan is a power hog.  Kind of tough to change out, since it's a double shafted jobby that both does the inside airflow as well as the combustion exhaust, and it's really buried in there.   I have installed a direct vent wall heater that requires no power, but it's undersized, so only good down to about 45F. (it was a craigslist deal I couldn't refuse)  But at least I won't be sucking power until it gets colder than that.  Bath and range hood fans I'm not as worried about, since their use is fairly brief, but I will keep my options open. 

I thought for sure I could turn up a 10~30VDC CFL, but no such luck.  In any case, it sounds like dealing with/eliminating that transformer would be good medicine no matter what.  I just wish I could find a 50A regulator I could tie right into it.  Solution #2 still is a winner.

Rover

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Re: 12v CFLs all burned out at once
« Reply #4 on: December 16, 2010, 05:48:17 PM »
Ghurd,

Thanks for posting I had no idea he may be getting 12 V AC (or near that).

So why not just use a bridge rectifier to get to DC, then a buck/bost for regulation on the line fo lighting. Would not have to run  each light with a 78XX .

Even with a 20A charger there will be voltage fluctuations at the load, epecicaly if it is a smart charger and depending on the variable state of the batteries.... my cranky little solid state schumaker wants to go to 15+ v on some occasions (er don't recommend that unit), however even the xantrex on the boat pushes quite high also.

You can pick up .. ok cheap, but functional 150w 12v buck/boosts on ebay if you don't want to build your own.

just curious...I'm probably way off base



Rover
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dnix71

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Re: 12v CFLs all burned out at once
« Reply #5 on: December 16, 2010, 06:05:02 PM »
Something really doesn't sound right here. I have Harbor Freight 12v lights with edison bases and they have worked for years and don't mind 14.5 at all. I've run them on a lot less, too.

If you have a proper sized battery bank and everything is tight the voltage shouldn't spike anyway, assuming it's actually 12v dc for charging. If it isn't, then like GHurd suggested, get a 12v power supply. Personally I would recommend a computer power supply. They are common and cheap and it's 12 point zero volts, not 13 or 14.

http://www.geeks.com/details.asp?invtid=PS480D-BLK&cat=PWR   16 amps at +12v That should be more than enough. On an ATX supply you short one lead to ground to turn it on, so
a momentary switch is all you need to get it going. $13 plus shipping.

Rover

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Re: 12v CFLs all burned out at once
« Reply #6 on: December 16, 2010, 06:44:46 PM »
 hey  dnix71 ,

I'm pretty sure I miss interepreted , out of ignorance, what the plug -in supply may be.  And even my  previous post I wasn't thinking the whole way through. The inout is just transformed down, so the result could be ~12 v AC..

And now.. I'm assuming there is not battery involvement, it just plugs into the vehichle's 12 v "grid"

so anytrhing comming in , is "as is" ...

once again... I may be completely off base. I only have a boat (which is an rv in water), the only supply we get is 120 vac from a marina.

 
Rover
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dnix71

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Re: 12v CFLs all burned out at once
« Reply #7 on: December 16, 2010, 07:25:46 PM »
My parents lived on a boat for many years. They had more power on the internal deisel genset than shore power. Shore power was 120vac via a twistlock connector.

They also had 12v on board for running most things. There was a lockout transfer switch involved in all this. Plus some circuit breakers. The fridge ran on 12 vdc but had an auto switching power supply that would take 12 vdc or 120vac whatever came in and converted that if necessary to 12vdc to operate.

The lights were all 12vdc, but common edison base 12v shop light style incandescent, which were not at all efficient. The radio and radar were 12v dc too. Only the a/c and tv and microwave ran directly from 120vac and there was not enough shore power at 30amps to run all 3 at the same time. When cooking my mom had to switch off the a/c compressor until the food was done.

If this travel trailer is wired for 12v, park power at 12v should be no problem as long as he has batteries large enough to buffer it. That seems to be a problem though, so taking 120vac and converting it with an ATX power supply should work fine, and cheap and easy. ATX power supplies are universal for P4 computers. Pretty much 90% of desktop computers can use that supply or one like it. The voltage regulation is very tight too because computers parts are expensive and sensitive to voltage.

Ungrounded Lightning Rod

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Re: 12v CFLs all burned out at once
« Reply #8 on: December 16, 2010, 09:19:22 PM »
I'd take a hard look at the batteries and the wiring to them, including for corrosion, loose connections, etc.  Also if their water level is up.  Also where the converter connects into the circuitry.

If they were properly connected, not sulfated, and not 'run dry", the voltage shouldn't have immediately gone up more than a volt or so when the converter was turned on (unless it was suitable for use as a welder).  It should have ramped up slowly over minutes to hours.  (And if the voltage HAD gone up that fast the batteries should have exploded shortly afterward.)

Titantornado

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Re: 12v CFLs all burned out at once
« Reply #9 on: December 16, 2010, 11:01:08 PM »
I didn't get a chance to check voltages and such.  (too busy putting out other fires tonight)  I did look up the power distribution panel.  It's made by Parallax Power Supply, and supposedly is a regulated, filtered DC converter.   I'm wondering if the bulbs are just cheap junk that can't handle any more than 12.x volts.  Sounds like I should give the Harbor Freights a try.    I'll start planning more once I get some voltage readings.

ghurd

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Re: 12v CFLs all burned out at once
« Reply #10 on: December 17, 2010, 11:04:30 AM »
I think there must be a power supply problem.
If the supply is regulated and filtered, then the 12V CFL bulbs should have been OK.
They should have a design voltage capable of handling at least 14.8V.

My camper only had a giant switch to go from battery mode to transformer mode.
When in transformer mode, the battery was out of the picture and would not hold the system voltage down.

Not sure any more, but it seems like it had another separate transformer output to trickle charge the battery at maybe 1A or something, but not what I would call a battery charger.
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Titantornado

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Re: 12v CFLs all burned out at once
« Reply #11 on: December 19, 2010, 06:34:07 PM »
First, I had a different model than I thought.  It's a Magnetek 6345.

OK, found the problem.   The way the converter/charger works is like this.   Not having park power connected, the 12v trailer circuits are connected direct to the battery through a NC relay.  With park power connected, the relay switches, connecting the 12v trailer circuits direct to the converter and disconnecting the battery from the trailer's 12v circuits.  Meanwhile, a separate 9A 'smart' charger is engaged for the battery.

When taking voltage readings, I did so first with the furnace running, and got a satisfactory reading of 12.6~12.8 volts.  However, when the furnace shut off (and pretty much no loads existed) voltage jumped up to 20.6 volts! (and so hence the execution of my CFLs)  So, the regulator portion is obviously toast.  Everything I've read about the Magnetek 6300 series is that they are pure garbage.   I guess I'll be looking to install a new one, or use Ghurd's original idea of disabling the converter portion altogether, running a separate charger when needed.

Rover

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Re: 12v CFLs all burned out at once
« Reply #12 on: December 19, 2010, 08:18:20 PM »
Based on the latest , I would go with Ghurd's idea.

1. Peace of mind, decent charge contrller takes the worry out of the equation. I'd probablu get rid of any switch over mechanism as well.
Rover
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Titantornado

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Re: 12v CFLs all burned out at once
« Reply #13 on: December 19, 2010, 08:30:49 PM »
Indeed.

So, anyone think it's worth trying to repair the CFLs?  I'm not very good with electronics, but I can get by as a parts swapper. (desoldering/soldering)

dnix71

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Re: 12v CFLs all burned out at once
« Reply #14 on: December 19, 2010, 10:36:46 PM »
Repairing your cfl's might be possible if you can get them apart without breaking something. If they blew immediately there may be a fuse.

http://store.sundancesolar.com/12vdcledreli.html  Sundance Solar has a whole page of 12v dc cfl's with edison bases. Maybe it would be easier to buy replacements and experiment with repairs later.

ghurd

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Re: 12v CFLs all burned out at once
« Reply #15 on: December 20, 2010, 07:59:32 AM »
Much like cheap inverters, I kind of doubt repairing them will be economical in your case.

Swapping which parts?  Order and swap the obviously melted parts, which melt again because they melted parts were melted from some unobviously melted parts, order and swap the 1st set of parts and the 2nd set of parts, which melt again...

Even if you get them working, between 10 parts orders with S&H, etc, it would not be unheard of to spend far more on the S&H than replaceing the CFLs would cost.
Been there, done that, not planning to repeat it.
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Titantornado

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Re: 12v CFLs all burned out at once
« Reply #16 on: December 20, 2010, 08:25:18 AM »
That's all I need to hear.1  :)

ghurd

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Re: 12v CFLs all burned out at once
« Reply #17 on: December 20, 2010, 08:43:22 AM »
Also, DC CFLs.
My experience is until they get to 11W, they almost use the same power as the 11W, but make less light.
7W uses nearly as much as the 11W, but makes like half the light?
Noveltity size 3 ~ 4 ~ 5W use a little less power, but they don't make enough light to be of much use, and even a semi-decent LED bulb makes more useable light with less power.

My experience with generic DC CFLs has been less than good too.  Short life, low output, high input, poor color temp, poor construction, etc.  I have come accross some generics that are OK, but being generic means I have no idea who made them or how to get more.

For DC CFLs, I pretty much only use Solsum 11W.  Cheaper than they used to be!
http://www.solar-electric.com/sol12voldcli.html
Edit-  They have not been made in Germany for many years, that part about "Do NOT use these lights on anything power source but 12 volts DC." is probably for people who have 12V AC in their camper.
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« Last Edit: December 20, 2010, 08:46:36 AM by ghurd »
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Titantornado

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Re: 12v CFLs all burned out at once
« Reply #18 on: December 20, 2010, 09:38:17 AM »
The Feit brand I have (had?) are 13w.  I have no complaints over output or color temp.  (looks just like 60w incandescent to me)  Life span I've yet to have the privilege of comparing.  I do have to use the more compact twisty bulbs to fit in the low clearance light fixtures I used for my 6'-5" ceilings.  I do agree that I wish there were quality 12v CFLs available, (like ones rated 10~30VDC and would be willing to pay a premium) or at the very least, lower prices on the already poor quality ones available now.

I'd love to use LED edison base bulbs, (I'm already using three Sunmia's 3Ws in one fixture, @ $27/bulb) but they can't even come close in lumens or color temp. (yet)  Now if they could cram 12 watts of LEDs into that bulb, they'd have something there. (though color is still horrible)  I wonder if I could influence the color by applying a transparent pigment on the bulb. (though, that would definitely kill the warranty)

ghurd

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Re: 12v CFLs all burned out at once
« Reply #19 on: December 20, 2010, 11:09:47 AM »
If most of the time the LEDs are doing the lighting, maybe try $1 120VAC CFL and a efficient 225~400W inverter with a known name on it?
Reliability is Hit&Miss, IMHO.  Some people have had great luck.

Honestly, for the price, ebay has some pretty decent LED bulbs lately.  Might take a try or 2 to find one you like.  Some are pretty sad.

I am pretty happy with one I recently ebay'd.  12V AC/DC.  4x1W LEDs.  Wide angle (60).
I had to get it in MR16 because the spacs looked closer to what I like, but the ebay adaptor was only 99 cents free S&H (different seller).  Or could pigtail the MR16 however you like.
More about it here-
http://fieldlines.com/board/index.php/topic,144188.0.html

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Rover

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Re: 12v CFLs all burned out at once
« Reply #20 on: December 20, 2010, 04:31:23 PM »
Yep, I like new crop of LED lamps. Most recently the ones using 5050 SMD LEDs , you can get them in  tower or corn configuration as well with e27 bases.

Titantornado, don't throw out those blown 12v CFLs , you can pry them apart and salvage the bases (you can do that on the 120v versions too) you end up with a nice e27 base with two wires. I just ordered a reel of 300 cool white SMD LEDs (5 meters, 60 LEDs/meter,trimmable every 3 LEDs), gonna make some of my own corn style lamps.  Color is 6000K (but I like bright white, I'l be making these for outdoor use) .

36 of the SMD 5050's gets you close o a 40W bulb at ~ 5W. I'm gonna go for 60 to 100 and see how it fares
Rover
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