Interior Lighting

[the_experience03]

I have a bunch of the "under cabinet" 13 watt tube units in my bus and couldn't be happier. I also have a fixture in my room that uses CFL's. The power draw is low and fluorescent lighting doesn't bother me in the least. I'd worry about serviceability with the LED's. You can get CFL's at the gas station.

 

[TygerCub]

Why one or the other? Why not both?

For workspaces, I absolutely must have fluorescent. But not the cheap models that buzz. I made the mistake of buying one of those inexpensive plug-in models from Lowes and the hum/buzz that most guys can't hear drives me and my mother crazy. No... for my crafting table, I'm going to have to go with the high end light fixtures that have a good defusion cover (to minimize shadows) and daylight color tubes. Any crafting work... be it leather, painting, woodwork, or just plain old playing around with "stuff"... requires great lighting.

But for ambient light throughout the rest of the bus, I'm going to go with LEDs. They have come a long way since their introduction decades ago. LEDs now come in a variety of colors, including "daylight". And, depending on the type of bulbs you buy, you can have light so bright you can't look at it without it hurting your eyes (I have a SINGLE BULB flashlight like that), to light that's just bright enough to see where you're going. The main problem with LEDs isn't the bulb's dying, but rather the hardware that breaks first. Good bulbs last a freakin' long time. Good fixtures should outlast the bus.

Another reason I want to use LEDs is to minimize heat in small spaces. Mainly my bunk area. Gotta be able to read in bed. Can't lose the space to a clawfoot tub, so I'll take the alternative and read in bed .

 

[Nachtwulf]

Hi Smitty,
As far as efficiency (from and electrical power and consumption standpoint), you really can't get any better than the LED's because of the almost 1:1 ratio of electrons passing through to photons being given out. I also agree with TygerCub that they have gotten better and the selection has become wide enough to get pretty much what you want. The LED's themselves are solid state, so unless you over-voltage them, overheat them (external temperature or trying to get too much wattage output without proper heatsinks), or physically destroy them, they pretty much last forever. The light output drops very slowly until the final few hours of life when it takes a nosedive, but 100,000 hours plus is not at all unusual. (That is 11.5 years of continuous light) I am a firm believer in building what you want, because only you know what suits your needs the best. If you need some ideas and info try this site http://www.instructables.com. Just type in LED Projects in the search bar, and you will get far more info than you ever wanted. I left the home URL for the site because other people might be interested in some of their other subjects.

Having said all that, I must say that there is nothing quite like the warm comforting glow of a lantern or gas lamp on a Winter evening... Ahhhhhhhh.

I wish you the best, Sir.
Lee

 

[Redbear]

Those propane mantle wall lamps were standard in the campers my neighbors had in the ''60s. And they are BRIGHT. I have one or two that work off of the small disposable bottles. But I HATE the hissing noise. I like quiet.

CFL's are easy. Just screw them in and turn them on. There are some negatives, though.

They have electronic circuit boards that pulse the tubes somewhere around the AM or shortwave bands instead of 60 Hz. Expect some interference if you have interests in those areas. They are pretty much all made in China, even with a US brand name. I've had GE outdoor CFLs with a 10-year warrantee die in 6 months. I've had others that have never been replaced since they were put in. Circuit board quality is a crapshoot. I'd say 4 out of 20 died a premature death. They are also most susceptible to power surges, not the tubes but the circuit boards. A lightning hit a mile down the road might or might not fry them. And they have hazardous innards to dispose of, if you do it properly.

LEDs aren't so easy. You can't say they are not ready for prime time, just look at the bright police light bars today. Some dealers aren't ready for prime time, though. And you really can't tell the quality of the design without risking destruction of the LEDs.

The problem with LEDs is that the current, not the voltage must be regulated. They get brighter and dimmer with changes in current. The current must be externally controlled. (External to the LED, that is. LED "bulbs" SHOULD have this put in.) If the voltage is constant, a series resistor is a dirt-simple way to control the current and protect the LED. When I had to add indicators to radio equipment, I would install a standard 2.1 volt, 20 mA LED in series with a 1200 ohm resistor. At 14.1 volts, the LED would be at half power 10 mA. The voltage would have to reach 26.1 volts to supply full current, and the LED would last "forever." The problem is the same as incandescents. I was using 2.1 volts for light and 12 volts heating the resistor, wasting 85% of the power.

So you can series the LEDs to drop more of the supply voltage. Some of the LED "bulbs" do this, as you notice the individual LEDs fail in groups. A daisy-chain of five standard LEDs in series require 10.5 volts. Add a 100 ohm resistor in series and connect to 12.500 volts, and you get full 20 mA brightness, it only draws 1/4 watt, and only 16% of the power is wasted as heat. Start your engine or battery charger, and the 14.5 volts through the 100 ohm resistor now provides 200% power to the LEDs, with another 28% wasted as heat. Then one LED goes "pop" and you have zero heat, zero light, and zero power consumption. This is probably what is happening with the cheap stuff on the market.

Change the resistor supplying 5 LEDs to 200 ohms, and the string can stand up to the charger, but the LEDs have only half power at 12.5 volts, and only 38% power at 12.0 volts. Using this scheme, they dim rapidly when boondocking.

The simple answer is a regulated voltage plus a current limiting resistor. You can easily regulate down to a fixed voltage below the battery voltage. A common 5 volt regulator chip or parts from an old 12-volt cell phone charger, plus limit resistors could step down 12-15 volts to 4.2 volts for pairs of standard LEDs. I think I will probably build fixtures with a 9 volt chip supplying strings of 4 LEDs at 8.4 volts. (Note: the new white and colored LEDs have higher non-standard voltages.) Another option is to pick up tractor-trailer taillight assemblies, and use them as dome lamps, if you can live in an amber or red environment.

The light from each LED is generally uni-directional, so they work better as reading lamps and task lamps than as area lighting. I am thinking of strings of them under cabinets or in a soffit to provide low-current indirect area lighting.

 

[TygerCub]

Smitty, if you get a reading lamp, may I suggest you pay the big bucks and get a good lamp from a sewing supply shop. They range from $40 to $80, but are made for folks who quilt and want "daylight" colored lamps. I bought a cheap ($20) reading LED lamp from a drug store that worked great for three months before the switch died. Loved the light, but the fixture was too cheaply made. I've since fixed the switch and it works great again... but for the hassle, I should have invested in a better quality light.

 

[Sojakai]

I was going to suggest that Smitty buy one or two of the LED lights to see how he might use them, and If he likes them. But he beat me to it.

oh, and the best part about LEDs, you can file down the tips of them to direct light into other directions. One of the Instructables required filing (faceting) LEDs to make them look like gems and to redirect the light coming out.