Tuesday, December 19, 2006

Discussion of LED Lights pt 3

Some Explanations and Clarifications

Item paying for itself.
At times I refer to a light paying for itself. I will admit to being quite a tightwad, and with this statement I am comparing the light either to getting a free standard flashlight, for which I would have to pay for batteries or in the case of electric lights, comparing to getting low cost standard bulbs at my local grocery store.

LED's in battery powered items vs electric items.
In time, LED's may be economical to use as household lights, but currently that is not really the case. They are still pretty much novelties, where the cost of the LED light will only barely be covered by the combined cost of replacing regular light bulbs cost of electricity saved.

In battery powered lights, on the other hand, LED's are well worth the small investment they require, and I suspect soon they will be on every hardware and department store shelf. In battery powered lights there is a twofold gain in economics. First, batteries cost more (by several orders of magnitude) for the electricity you get, and second, LED's used with batteries don't require a power supply to convert the relatively high voltage found in your walls to the couple of volts used by the LED's. (I will talk later about the failure of one of those power supplies)

In the gray area in between commercial electric costs and single use batteries are UPS power supplies and generators. Typically these sources of electricity seem to me to be about one order of magnitude more expensive than commercial electric power (I have studied generators and rechargable batteries, but not in depth).

Economists are already starting to talk about converting to LED's. If your favorite economist or home improvement expert isn't talking about them yet, check these references from Clark Howard.
clarkhoward shownotes 2006/11/23
3rd story is "LED lighting makes a spark"

and an older reference from his archives
clarkhoward.com shownotes-category 4/100/142
look at the Jan 12, 2004 story at the bottom of the page

What I would love to see is a discussion on having a secondary set of wires installed in homes to carry, maybe 4 volts, for LED lighting.

One last note:
Ideal low battery indicators.
I mentioned that my 5-LED headlamp would be better if it had a low battery indicator. Two problems I have seen with low battery indicators are they are either too subtle, or they take some energy to run - defeating a large part of the economy of the device. I would love to see a device like this designed so a couple of the LED's would quit when the batteries are down to about 20% charge left.

I expect to do maybe two more articles in this series on LED's - and maybe include discussion of compact fluorescent lights. I welcome any discussion, especially if you have any experience with household LED lighting or UPS or generators.


Sunday, December 10, 2006

Discussion of LED lights pt 2

My best and worst buys in LED lights have had more to do with my needs than with the products. Most of the items I have bought have been fairly good quality and did about what they said they would do. Therefore I will just list the items I have and their pro's and con's.

LED modification for Maglight.
I found a modification for a regular Maglight - the kind that takes 2 AA batteries. It is basically a replacement for the bulb and reflector and has 3 LED's The only drawback I can see is that it has no focusing. You get a semi floodlight effect. You can still take the top off, use it for the base and have the effect of an electric candle. On the plus side, it gives twice the light and about 3 times the battery life. I paid about $8 for it, meaning it will pay for itself in the time it normally takes to go thru 10 or 12 pairs of batteries. (Unfortunately, I don't use a maglight that much.)

LED headlamp from All Electronics.
Since a large part of my job involves working outside either just before dawn or just after nightfall, what I use the most is a headlamp. Using a headlamp means I can use both hands and the light just goes wherever I look. The one I currently use is the HL-1 from All Electronics. It is a fairly cheap one that runs on 3 AAA batteries, and has 5 LED's. It is very lightweight and runs for hours on a set of batteries. No moving parts except the switch and latch on the battery compartment. So far it has survived a few months where I work - and that is fairly impressive. One slight beef is that the light output drops off so slowly that I am straining before I realize what the problem is. Also the switch has 3 positions - one makes it a flasher. Don't need that, and I keep threatening to put a drop of glue in the switch path so it won't go there. I Haven't tested it in a downpour, and I don't expect it to be waterproof. It just doesn't have any seals. If it didn't have the flash, was waterproof, with a bit heavier latch and had a low battery indicator it would be perfect (for fair weather).

LED headlamp from Ray-O-Vac
(Available at many department stores and hardware stores).
I just purchased a similar headlamp from Ray-O-Vac. This one seems to be more watertight, and has a healthier body - including the switch. I also expect it to be more watertight than the cheaper one above. The switch has three on positions and off. First is two red LED's, then one white one, and finally a lamp like the one on a Mag Light. I haven't used it enough to comment too much, except that I think it should have one red LED and two white ones. There isn't much difference between the red and white settings except the color. The cost is about $13 dollars, so it will be a while before it pays for itself.

Also from All Electronics - 14 LED flashlight.
Costing about $11, this flashlight uses 3 AAA batteries and produces about the same light as the old 4 D battery flashlights of several years ago. The light isn't focused, so it doesn't have the "reach" of a 4 battery flashlight, but for most tasks it is more than sufficient. Eventually the savings in batteries will pay for it, but the biggest savings for me is the size and weight. At about 4 or 5 ounces, and about as big as two D batteries (without the flashlight) this frees up a lot of room in a tool box or backpack. It is marginally waterproof (has threaded collars and rubber o-rings), so a single rainstorm shouldn't cause trouble - but was not meant for that and after a thorough soaking you would probably find some water in it. I have been using this light for a couple months and it seems reliable. I dropped it once and it got flaky. A check inside revealed a bent spring, which I straightened and it is as good as new.

I will try to write more about these and others in the weeks to come.


Friday, December 08, 2006

Johnnie Bryant Hunt died yesterday

He was an industry giant (trucking), a Christian, and philanthopist.

todaysthv.com _ More than business

truckdriving jobs jbhunt _ Johnnie Bryant Hunt.htm

todaystrucking _ Trucking Icon JB Hunt

I suggest, in his memory, give to charity.

If you can't think of anything else, there are
thousands of Salvation Army kettles,
and they have food banks in almost every town.


Monday, December 04, 2006

Discussion of LED lights pt 1

Over the past year I have bought about a half dozen LED lights of various types. Flashlightss, "head"lamps, a lantern, and a reading light. Most I am very satisfied with, as they are more efficient than fluorescent and supposed to have a longer life expectancy.

The longer life is key to their economy in most cases because of the cost of the items themselves. In most cases, LED based lights will cost 2 or 3 times as much as their counterparts. While this initial cost is getting better, there is a long ways to go before LED's will become "mainstream."

In cases where the lights are powered by batteries, the LED's are making fast inroads, and all but one of my purchases have been battery powered items.

It should be noted that none of the LED lights I have bought are considered "cutting edge," even though some of them have only been around for 2 or 3 years. (LED's of fairly high intensity have been around for several years, but only recently came down to a price people were willing to pay.) There has been new generation of superbright LED's coming out over the past several months, but I have only gotten one recently.

Out of all of the LED lights I have bought, only one has failed, and that wasn't the LED assembly - but its internal power supply.

In future articles I will discuss the individual items I have tested, their good points and bad points.