Bright, simple, cheap, durable, rustic dome light!

[gyroguy]

I wanted a bright, simple, cheap dome light that looked kind of rustic to go with the wood paneling inside the Crocodile Tear. I put in a regular 12V dome light, but it isn't bright.

Since I was using a 12VDC to 120VAC 130-watt inverter, i could use an AC bulb. At Home Depot I found 5 13-watt fluorescent bulbs for $9.99.

These will work with a cheap square-wave inverter (unlike fluorescent tubes!) and are very bright for the wattage. 13 watts fluorescent = 60 watts incandescent. 23 watts fluorescent = 100 watts incandescent.

Next step was designing a protector for the little curlique light bulb. I found that either the 13 watt or 23 watt would fit into a 1 quart Mason jar with a 3" mouth. I could put the jar lid in the jar ring and screw the lid to the wall. Actually, I got a piece of 1/8" aluminum, cut it the diameter of the inside of the jar ring, and filed down the thickness so the aluminum fit neatly onto the jar ring. I bolted the aluminum to the wall, which also stopped the jar ring from turning. Next step was to make holes through the aluminum top and the wall, add rubber grommets, and run the wires through the wall to the inverter and a wall switch.

The Mason Jar dome light is attached on the wall over the front closet. I've got the height of the jar lid up enough that the side of the jar touches the ceiling. The jar screws on for a friction fit. It's a tight screw-on that really protects the fragile little bulb. Also looks rustic, rustic, rustic! My East Texas horse-riding friends like it a lot. And it's bright enough to read stock quotations from the newspaper at night. The bulb doesn't run as hot as an incandescent light, and you can put your finger on the lighted bulb without getting burned. The bulbs last something like 2,000 hours.



FYI, if you're running a 12 VDC system only, check the camping department in Wal-Mart for a 12-volt version of this fluorescent bulb.

In the Gyroguy personal album, I have a partial picture of this lighting fixture in the Crocodile Tear. Look for the dome light/vent photo. BTW, the black thing on the bottom of the vent is a 25 CFM computer fan.

If you want a bright, simple, cheap, durable (and rustic!) dome light, consider this one.

[Dale M.]

Unfortunately those type of florescent bulbs are not supposed to be used in a enclosed fixture... Read instruction/warning on florescent bulb package...
Although they are low power consumption there is still a heat issue in enclosed fixture...

Dale

[Chuck Craven]

I have one in a lamp with a glass shade that is open on the top and bottom. The glass shade gets quite hot. Not enough to burn but if the lamp was enclosed; it would burn one or start a fire.

Chuck

[GHOSTSSX]

What does it say???(For those of us who do not have one handy!!)

Thanks,

CHUCK

[Dale M.]

What does it say???(For those of us who do not have one handy!!)

Thanks,

CHUCK

....do not place in enclosed fixture.....

Dale

[gyroguy]

Unfortunately those type of florescent bulbs are not supposed to be used in a enclosed fixture... Read instruction/warning on florescent bulb package...Although they are low power consumption there is still a heat issue in enclosed fixture...Dale

The package of 5 "Ultra Mini Spiral Lamps" made by Commercial Electric of China says, and I quote: "Usages: Suitable for totally enclosed fixtures. Usos: Apta para equipos de luces completamente cerridos." Here's a copy of the package label:



I wouldn't have put the bulb in an enclosed Mason Jar otherwise.

I've used a pair of these 13-watt bulbs in my totally enclosed bedroom ceiling fixture for the last three years. All the bulbs were bought at Home Depot. The brand on this particular bulb appears to be "Commercial Electric," and the bulbs were made in China. They are 10,000 hr bulbs.

In the Crocodile Tear, bulb has not been on continuously for more than 2 hours. Weather has been cool. The Mason Jar gets warm, but not what I'd call unreasonably hot (this is subjective, since I haven't put a thermometer on it).

Agree, Dale, there is a heat issue in an enclosed fixture. Need to use the lamp and Mason Jar more to see how significant the heat issue is. I expect the heat issue would be a larger issue with the 100-watt equivalent bulb. I have not used one yet.

Dale, thanks for the comment, since it concerns safety. Any clue why your bulb and mine would have contradictory labels?

[mikeschn]

I suspect that someone's English is not 100% up to par. The photo on that package does not illustrate fully enclosed light fixtures. Made in China? That's explains everything.

Mike...

[sdtripper2]

Why not go to Incandescent-to-LED-Relamping inserts
for brighter light in the same fixture you have now for your dome light

The light can be much brighter than regular filament bulbs and there is less
of a heat issue in the small space and save battery power as well.

Here a couple of sources for LED replacement for old bulbs:
LEDtronics, Inc
http://www.ledtronics.com/ds/B606/
Festoon Dome Bulbs
http://superlumination.com/festoon.htm
***

Incandescent-to-LED-Relamping Energy Cost Savings Calculation
http://www.ledtronics.com/savings/default.asp

[Dale M.]

OK....

Well for anyone contemplating buying this type of florescent bulb, I suggest you read the package before purchase to see if it is applicable to your application....

Dale

[gyroguy]

Why not go to Incandescent-to-LED-Relamping inserts for brighter light in the same fixture you have now for your dome light? The light can be much brighter than regular filament bulbs and there is less of a heat issue in the small space and save battery power as well.

This is a good idea, and I considered it. It appeared to me that I would need four or more little dome light bulbs to equal one 60-watt incandescent... or LOTS of LEDs. Remember, I want a dome light I can read by. How many LEDs wouild it take to produce 900 lumens? What would it cost?

Mike, the label I printed has one totally enclosed lighting fixture... the one on the far right. That is the same kind of lighting fixture as on my bedroom ceiling. It is not vented.

I'm not mentioning this to be picky. Real question is, what is safe? It wouldn't matter if every label said totally enclosed usages were OK, and my trailer caught fire!

[sdtripper2]

Gyro:

I think you are over estimating the 900 lumen's you will need to read inside
a cabin where the light source will be less than 3 feet from your book.
I have standard lighting for a dome light and it is more than enough to read
by? I can't imagine one needs a light source the size of a 60 watt bulb inside
a small TD to read. Maybe you need a dome light with two standard light
bulbs for double the light source but to have a standard light bulb seem over
kill to me.

I wonder what others think?

Do others use the light source that Gyroman would have in their TD?

[bdosborn]

Steve,

I'm not a big fan of the quality of light the CF puts out. Too blue for me and bad color rendition. They can also have problems starting in cold weather. Here's what I plan to do for my next lights:
http://www.myroadtrek.homestead.com/LEDLights.html
http://www.title-3.com/LEDLights.htm
Incandesent and LED so I can have the best of both lamp types; good color rendition if I need it and low power consumption if I don't. Camping World has the light for around $10.
Bruce

[sdtripper2]

Bruce:

Now your suggestion for both light sources seems the E-ticket to do the job.

I think my light has two light bulbs but this model you suggest has both with
an LED as one source.

This would make me happy if I were in Gyroguy's search mode.

Will wait to see if he agrees?

[gyroguy]

Incandesent and LED so I can have the best of both lamp types; good color rendition if I need it and low power consumption if I don't. Camping World has the light for around $10. Bruce

Good idea, Bruce.

I was trying to figure out a good way to be objective about light output. Just for the fun of it, I set my photographic light meter at 200 ASA and adjusted it to measure the light falling on it. Then I took a tape measure and put the head of the light meter 15 inches away from the light source.

Here are the EV (Exposure Value) readings (taken at night with the light listed as the only light source):

EV 13.3 13 watt fluorescent bulb, 120 VAC, with power from 12 VDC to 120 VAC inverter. 120 VAC bulb, 13 watts, 0.1 amps.

EV 13.3 12VDC dome light with #1141 incandescent bulb, with power from 12VDC automobile battery. 12.8 VDC bulb, 18.4 watts, 1.44 amps.

EV 13.6 60-watt clear incandescent bulb, 120 VAC, 0.5 amps.

EV 13.6 15-LED flashlight, 2” reflector, 6VDC, flashlight batteries, measured in the cone of brightest light. Watts, amps unknown, but probably the least of all. For 18 LED bulb in a dome lite, estimate 12 VDC, 1 watt, 0.083 amps.

The first three lights are all about the same brightness, but the amperage needed to run them varies considerably. The 13-watt fluorescent is most efficient of the three.

I have to fudge on the LEDs, because all I had was a flashlight. I took the light reading in the brightest reflected light. Would I get as much light from 15 LEDs in a dome light fixture? I doubt it.

So here are my thoughts.

For dry camping, onboard trailer battery only, I'll take the 13-watt fluorescent bulb. With the low amperage draw, my battery will last longer. (I realize there is an amperage penalty for using the inverter.) I don't see the color rendition problems you mentioned, and I use these bulbs in my home.

For shore power with a battery charge being maintained, I'll take the 12-volt bulb in the dome light.

The LEDs appear to use the lowest amperage, with 18 LEDS about 1.2 times as efficient as the fluorescent bulb. I don't know if they produce as much light because I don't have one to check. But at $18 per bulb, versus $2 per fluorescent bulb, they are expensive alternatives.

Okay guys, I've done my homework. What do you think?

[bdosborn]

gyroguy,
Nice write up. I think this is the first real light output test I've seen on the forum. One thing to remember is that an inverter that is lightly loaded can be pretty inefficient. I wouldn't be surprised if the total current draw for the fluorescent lamp on the inverter isn't about the same as the 12V incandescent. My LED strip light uses about 1/2 amp at 12V DC.

Bruce
P.S. Here's a link to some LED lights I made:
http://home.comcast.net/%7Ebdosborn/tea ... htBar.html