Sometimes it's the challenge fo fixing things yourself. Sometimes it's about saving money. I had two recent experiences. Of the car alarm, I chose to pay a small amount rather than spend house tracing wires.
I finally made the switch this year to LED bulbs. I bought the EcoSmart brand from Home Depot. They are indoor/outdoor rated, flicker-free (I assume full-wave rectified), and the one-light-doesn't-take-out-the-whole-strand variety. I'm extremely pleased with them so far. They also seem to have thought out the connector a little better, as they utilize a pair of round female pins to accept the LED lead that's folded over against a plastic pin. I have found a few sloppy female contacts but they are definitely better than the traditional ones.
Is a full wave rectifier enough to remove the flicker? One could add a filter capacitor, or use a nice regulated laboratory supply. LEDs usually want a current regulated supply, though, and I don't know how they actually do it.
A couple of years ago I bought a bunch of strings of LED Christmas lights to go along the 200 foot fence in front of our house, thinking that this would be a one-time investment. Boy- was I ever wrong. The LED's didn't fail but the sockets did. All the lights got donated to the Thrift Store just after Christmas. During the after-Christmas sales last year I ended up buying some "commercial grade" LED lights that were permanently attached to the string (no connectors!) and had a 5 little volt switching supply for each string. They've been up since Thanksgiving, and so far there are no failures (knock on wood).
Glen, there are a number of posts and blogs about various flicker free designs and how to make flickering lights not flicker. The common wisdom is that the cheapest lights use a single diode for half wave rectification. Apparently a full bridge is how most "hackers" fix theirs, and how some companies solve the flicker. I have seen reports that some use capcitance instead. One post I saw someone make a "dongle" out of old plugs to go inline that had a full bridge. The problem I see with this is that you now are running the LEDs twice as hard. Current limiting resistors in the strands are likely to overheat and the life may be affected of the LEDs themselves. While LEDs tend to be very high life, those in these light strings seem to be very low quality and very prone to failure. So... I decided not to tempt fate and just go for a strand that was flicker free from the start.
Most of the light strings I own came with a spare fuse and a few spare bulbs. The challenge is in finding those spares if and when needed. I do agree, however, that at such a low price, they really are disposable.
If I question a particular string for any reasn, I tend to throw it out. Given the price point, I have to assume that every part of the string is made as cheaply as possible and I'd rather not risk a fire than save a few bucks.
Curie_US, I liked your green comment! It is funny to me that we take live trees, kill them, set them up in our home and then add small distributed heating elements to them all around. As a kid I never thought of this as being odd or wrong, now I am considering moving to a live potted tree with low power lighting and then planting it in the spring.
All that said;
I do really enjoy the balsam fir smell in the house and agree that the lights are a real pain the 2nd or 3rd year of use, which is when they start to fail. It took 3 hours this season to fix all the lights and at the end, I had 3 bad strings and 3 working! I wonder how hard it would be to fabricate a LED string (all parrallel) by hand? Does anyone have a suggestion for a cheap but robust connector that could be used for this effort? Merry Christmas..
I agree! The smell of fresh balsam fir @ CHRISTmas time is VERY magnetic to the season! We don't have that many resources for good live trees here in FLA. The artificial plastic ones have taken over dominance unfortunately.
I am of the age when we recycled an awful lot of daily items, so when I see comments about "green", it makes me LAUGH like heck! We recycled diapers, beverage bottles, milk bottles, and all sorts of items. But, the past 40+ years has put consumers into this "throw-away" mindset, and now we're bombarded w/ the opposite message. Like it or not, but one of the stimuli for this mode of living was due to a lawsuit. It seems that someone bought a quart bottle of beer (remember those quart bottles??? ... I SURE do!), and there was a used matchbook still inside which survived the washing/sterilization process. That person sued, and that was the end of returnable beverage bottles.
I can tell you one thing..... IF there was MORE recycling at the home level by re-use, the landfills in this country & elsewhere would NOT be so overwhelming in size, nor would they be so expensive to maintain from a government point of view.
As we approach this "special" holiday (Holy Day) .......... BLESSED CHRISTmas to all & HAPPY, HEALTHY NEW YEAR, too!
i too agree puttng up lights such an imporant thing that it can make many couple's fight on simple issue. But the lights available especially the low cost ones are so bad in quality, you cant think of usng next year and another source of e-waste.
We have also really enjoyed our LED strings except that the X10 modules we use to time all the various trees and outdoor lights don't detect them and think they need to turn off - it took us a while to figure out it was the X10, not the LED strings. We had to return to old fashioned timers.
BobsView, LEDs do have a fantastic lifespan, which should far outlast this sort of products typical lifespan. I think there are two issues here. First, these particular LEDs tend to be so cheaply made (die, leads, and wirebonding), and poorly tested, that they have much-higher-than-usual failure rates for this sort of product. Second, I suspect that the vendor probably does some final testing or color binning on the strand itself. If not, then I suspect they still prefer sockets to allow for a single strand to be populated with different colors as customer demand merits. Keep in kind that labor in these countries can be ridiculously cheap. As a for instance, a friend who was in China at the time relayed to me how the first major fiber optic deployment from Beijing to Shanghai was trenched entirely by hand (shovel). The use of trenching equipment was more expensive than manual labor.
NASA's Orion Flight Software Production Systems Manager Darrel G. Raines joins Planet Analog Editor Steve Taranovich and Embedded.com Editor Max Maxfield to talk about embedded flight software used in Orion Spacecraft, part of NASA's Mars mission. Live radio show and live chat. Get your questions ready.
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