Name two things that will probably never happen...

[Matt Day]

Jim, by the time there are flying cars they will surely be driverless and require no human input. So it won’t matter if we’re still a bunch of “tick bit yahoos”.

[Mel Fulks]

Matt, I think it was Ford in the 1950s that wanted to make flying cars. The wings folded up in "street mode". I think the Feds complained.

[John K Jordan]

My house is all LED lighting. I have had one LED bulb fail in three and a half years. Cree replaced it with TWO bulbs of a newer design that work better in enclosed fixtures. Previously, I was replacing CFLs monthly in a fixture with three bulbs. I would literally take a dozen bulbs at a time to Home Depot for recycling. The bulbs were GE brand and cheap with subsidies.

There is always anecdotal "evidence." I had one low-wattage CFL burning continuously, day and night, for 7 years - the one I replaced it with has about a year on it now. Most of those in my garage are almost a decade old. (BTW, I read good advice once about extending the life of CFLs - when turned on, it can help to let the bulbs come up to temperature before shutting them off. The article suggested 15 minutes. From what I know of thermal shock in electronic circuits it makes sense.)

Let's all check back in 5 or 10 years with updated light stories.

JKJ

[lowell holmes]

Politicians worrying about us instead of themselves.
And my Lab staying off of the couch.

[John K Jordan]

- An "inside-outside" cat that wants the door opened fewer than 30 times a day.

- My Lovely Bride preparing a less-than-incredible meal. (she who lives to cook)

[Lee DeRaud]

There is always anecdotal "evidence." I had one low-wattage CFL burning continuously, day and night, for 7 years - the one I replaced it with has about a year on it now. Most of those in my garage are almost a decade old. (BTW, I read good advice once about extending the life of CFLs - when turned on, it can help to let the bulbs come up to temperature before shutting them off. The article suggested 15 minutes. From what I know of thermal shock in electronic circuits it makes sense.)

I've had regular incandescent bulbs last decades in rooms with dimmer switches. My guess is that it's because the bulbs ramp up over the half-second or so while I'm sliding the dimmer on rather than just the instant full-power surge from a regular switch.

[lowell holmes]

Swmbo saying " That mess is OK, just leave it until tomorrow".

[Lee Schierer]

1. Getting younger

and

2. A woodworker saying he has enough clamps?

[John K Jordan]

I've had regular incandescent bulbs last decades in rooms with dimmer switches. My guess is that it's because the bulbs ramp up over the half-second or so while I'm sliding the dimmer on rather than just the instant full-power surge from a regular switch.

Yes, I understand reducing the power-on surge can be a big help to many things electrical; that and the mechanical expansion/contraction of circuit traces and components from heating/cooling cycles are apparently common killers of devices. I think one reason for the long life of circuits today in things like tablets and phones are due in part to almost microscopic surface-mount components combined with minuscule current draw. (For an eyeopener, take an outdated smart phone apart and look at the circuit board with strong magnification.)

Also, if you sometimes use the light at least partially dimmed, fewer molecules boil off the white-hot filament and it will last longer. Years ago I started buying bulbs rated for 130 volts, more expensive but they definitely last longer. A small decrease in the voltage gives a huge increase in bulb life with just a small decrease in light output (and color temperature). Look at how the live doubles with a 5% voltage reduction:

voltage_vs_bulb_life.jpg
Applied Illumination Engineering, Jack Lindsey

You also used to be able to buy a button sized dimmer to drop in the light socket under the bulb and reduce the power to the bulb a little - this made the bulbs last "forever".

I have maybe a dozen of these desk lamps in the shop and house with dimmers and incandescent bulbs (halogen) and I rarely use them at full brightness - some of the bulbs are probably 40 years old now with some use every day. The only bulb I've ever had to replace was on a lamp I loaned to teenager who probably used in on full brightness all the time. And probably accidentally left it on all day.
https://www.staples.com/Tensor-Halog...product_382362

JKJ

[Bill Jobe]

I've had very poor luck with CFL and led screw in bulbs.
As for energy savings, I'm not convinced the technology is there yet.
Furthermore, these types of bulbs are far more of a pollution problem. How many people do you suppose take an led or CFL to a recycling center when it fails?
I have gotten some pretty good led ceiling lights over the years, but screw in....not so much.
I don't see the advantage of either over and incandescent in colder climates such as here in the upper Midwest in winter. Incandescent bulbs last longer, they are cheaper, they produce less pollution when thrown out, and, if the wasted energy goes to heat, where is the loss? We heat our homes in winter.
Seems to me a simple incandescent bulb is 100% efficient in winter.
But more than likely I lack understanding that would prove me wrong.

[Mark Bolton]

It's not the science but the product design and manufacture. As discussed in an earlier thread,

1) The tiny LED light sources inside the fixture or bulb will last an incredibly long time IF they do not overheat. I found some fixtures pay little or no attention to heat sinking to remove heat from the semiconductor. I bought some fixtures and returned those that did not properly disperse heat. It's not rocket science, just $$.

2) The electronics that drive the LED are complex and far more likely to fail than the light emitting diodes. Especially if kept hot.

I've had several LED fixtures fail and being non-repairable just added to the landfill problem and the slim wallet problem. My current policy: only buy fixtures with replaceable elements. I wish the best for those who have filled their shops with cheap LED fixtures.

JKJ

And not to mention when you start to figure that half of the countries utility companies are supplying an over-voltage condition because they are unwilling to invest in their aging infrastructure, you will see why everything from appliances to light bulbs last fewer and fewer hours. I will nearly guarantee you that the utility companies, or their executives, are vested heavily in financial gains from failed equipment and appliances. Entire dishwashers and refrigerators and any other appliance are winding up in the landfill because a motor, compressor, circuit board, failed in a couple years and the replacement, and installation, are 2/3 the cost of a new appliance so out with the old, in with the new.

[Lee DeRaud]

Also, if you sometimes use the light at least partially dimmed, fewer molecules boil off the white-hot filament and it will last longer. Years ago I started buying bulbs rated for 130 volts, more expensive but they definitely last longer. A small decrease in the voltage gives a huge increase in bulb life with just a small decrease in light output (and color temperature).

I vaguely recall that the life increase is something like the fourth power of the voltage reduction. (Started as a EE major 50 years ago, switched to math...go figure.)

It's also certainly possible that the dimmer circuitry itself never really gets to 100%: these are old-school analog widgets, circa 1990. I think I'm down to one or two of them, as various lamps and fixtures transition to LED and the dimmers themselves get replaced with 21st-century tech.

[Dave Anderson NH]

John and Lee. As you have both said, heat is the enemy of electronic devices. A 10 degree C rise in the junction temperature of an IC will cut the mean time between failure in half.

[Bill McNiel]

Politicians worrying about us instead of themselves.
And my Lab staying off of the couch.

Absolutely true, same here!

[Mike Kees]

I really like the toughness of the LED bulbs. They dont break in my trouble light or the bulb in my bandsaw light.