Search Results for: compact fluorescent

Compact Fluorescent Bulb Autopsy

I fished the failed CFL bulb from the recycling box:

Failed CFL - case damage

Failed CFL – case damage

The straight-ish crack between the tube ends looks like it happened as the (yellowed) plastic ruptured and hardened.

Not wanting to get a face full of glass fragments spiced with metallic mercury, I wrapped a blast shield around the spiral tube:

Failed CFL - tube wrap - shattered base

Failed CFL – tube wrap – shattered base

The terminal ends fit loosely in the crumbling base at the start of this operation, leaving the tube wobbling above the base. The plastic cracked as I wrapped the tube, so, for lack of anything smarter, I applied a pin punch to break away the rest of the upper base.

The tube doesn’t fit into a socket, of course, and terminates in four wire connections:

Failed CFL - tube terminals

Failed CFL – tube terminals

Those wires pass through notches on the edge of the PCB, bend around the board, pass through vias, and get soldered to pads. The solder side faces the tube, with all the components nestled into the base toward the screw terminals:

Failed CFL - PCB solder side faces upward

Failed CFL – PCB solder side faces upward

The component side sports a surprising number of parts:

Failed CFL - PCB components - 2

Failed CFL – PCB components – 2

A view from the other direction, where you can see the tube wires curling around the edge:

Failed CFL - PCB components - 1

Failed CFL – PCB components – 1

I generally harvest inductors & suchlike, but it got really really hot in there and, methinks, cooked the life out of the parts:

Failed CFL - overheated capacitor

Failed CFL – overheated capacitor

The PCB date code stamp could be “730”, suggesting either 1997 or 2007. In any event, it’s been a while.

I hope LED bulbs outlast these things, but I have my doubts …




Failed Compact Fluorescent Bulb

An overhead light in the Basement Laboratory went dark:

Failed CFL bulb

Failed CFL bulb

One end of the twisty tube got really really hot as it failed!

The Lab didn’t smell of electrical death, so the bulb must have failed while I was elsewhere. Metal enclosures with actual UL ratings suddenly seem like a Good Idea …


Compact Fluorescent Bulb Lifetime: Another Data Point

Each of the three chandeliers in the Poughkeepsie Train Station sports 36 bulbs in two rings. When the station opened in 1918 they installed those newfangled incandescent bulbs that were all the rage at the time. The color of the bulbs in this Wikipedia picture, dated October 2007, suggests that tungsten ruled for at least nine decades:

Poughkeepsie Train Station Interior

Poughkeepsie Train Station Interior

Since then, they installed chunky compact fluorescent bulbs that probably provide the same amount of light, minus the pinpoint highlights from tungsten filaments in clear bulbs. This view from below the central chandelier shows the layout and some detail of the carving & decorative sockets:

Pok RR Station Middle Chandelier - detail

Pok RR Station Middle Chandelier – detail

In addition to being decorative, those chandeliers also give useful data on the reliability of compact fluorescent bulbs. With the contrast stretched the other way to make the bulbs easier on the eye, count the number of deaders in …

Chandelier 1:

Pok RR Station Chandelier 1

Pok RR Station Chandelier 1

Chandelier 2:

Pok RR Station Chandelier 2

Pok RR Station Chandelier 2

Chandelier 3:

Pok RR Station Chandelier 3

Pok RR Station Chandelier 3

I took each picture from a vantage point showing all the deaders; the bulbs hidden behind the central dingus work.

Let us assume all 108 bulbs were installed at the same time and, given the number of deaders, haven’t been touched since then (although they’re not covered in fuzz, which suggests that they’ve been dusted within living memory). I was there in mid-afternoon, so the bulbs probably burn 24 hours/day and aren’t subject to early failure from frequent starts.

So, in no more than five years, 108 CFL bulbs have a 4.6% failure rate, which works out to 0.9%/year, more or less, ignoring any infant mortality. If they’ve been up there for the last 2.5 years, then it’s 1.8%/year.  Replacing deaders since installation, of course, makes it worse than that.

Over the course of a decade, a compounded 0.9% failure rate will kill 9.4% of the bulbs. After 20 years, 20% will be dead. A 1.8% annual failure rate kills 20% and 43%, respectively.

Now, I’ll grant you that tungsten bulbs burn far more energy over that time, but replacing a percent or two of those complex and somewhat eco-hostile CFL bulbs every year cuts away a big chunk of the rainbows-and-pink-unicorns delight involved in Saving The Planet.


Early Compact Fluorescent Bulb Failure

Early CFL Bulb Failure

Early CFL Bulb Failure

Being that sort of bear, I tend to make notations like this. Sometimes I’m delighted the next time the inscription sees the light of day and sometimes it ticks me right off…

Much of the energy-saving advantage of CFL bulbs comes from their touted long life. I’d say a year isn’t nearly long enough to reap any benefits…

There is certainly a warranty on the bulb, if only I’d:

  • saved the empty package and
  • had the original receipt and
  • be willing to call a presumably toll-free number and
  • go through whatever hassle they impose to swap the bulb

They know none of us will get very far down that checklist…

FWIW, the box of smaller CFL bulbs on the shelf says they have a two-year warranty “in normal residential service of 3 hours per day”. I’m sure the number of starts factors into it, too.


Fluorescent Shop Light Ballasts, Redux

As usual, several shoplights didn’t survive the winter, so I gutted and rebuilt them with LED tubes. Even the fancy shoplights with genuine electronic ballasts survive less than nine years, as two of those eight “new” lamps have failed so far.

The dead ballast looks the same as it did before:

Electronic ballast - label

Electronic ballast – label

Some deft work with a cold chisel and my Designated Prydriver popped the top to reveal a plastic-wrapped circuit board:

Electronic ballast - interior wrapped

Electronic ballast – interior wrapped

Perhaps the flexy gunk reduces the sound level:

Electronic ballast - interior A

Electronic ballast – interior A

While also preventing casual failure analysis and organ harvesting:

Electronic ballast - interior B

Electronic ballast – interior B

The black gunk smells more like plastic and less like old-school tar. It’s definitely not a peel-able conformal coating.

One the other paw, the two magnetic ballasts in another lamp sported actual metal-film capacitors, which I harvested and tossed into the Big Box o’ Film Caps:

Shoplight choke ballast - film cap

Shoplight choke ballast – film cap

If a dying ballast didn’t also kill its fluorescent tube(s), I’d be less annoyed. I’m running the remaining tubes through the surviving fixtures, but the end is nigh for both.

The new LED tubes produce more light than the old fluorescents, although I still don’t like their 6500 K “daylight glow” color.



Long-lived CFL Bulb

This compact fluorescent lamp seems to have survived nearly two decades of use in a desk lamp:

Desk Lamp - long lived CFL

Desk Lamp – long lived CFL

It had plenty of starts, although maybe not so many total hours, as the other CFLs you’ll find mentioned around here.

I swapped in a similar CFL and we’ll see what happens.

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LED Bulb Lifespan vs. Warranty

I picked up a $35 LED bulb that’s allegedly equivalent to a 75 W incandescent, replacing a 100 W equivalent compact fluorescent bulb that an X10 relay switch couldn’t turn off cleanly, for a torchiere floor lamp. ‘Nuff said about early CFL failures.

It has both upward and downward facing LED chips that light up the diffuser and ceiling in equal measure. Both strings are visible from the side due to the heavy molded plastic lens around the chips:

LED Bulb

LED Bulb

Some interesting bits from the package:

Home Depot LED Bulb Warranty

Home Depot LED Bulb Warranty

A 22.8 year lifespan at three hours per day works out to 24.983×103 hours. I wish I could have heard the arguments about whether they could claim a 23 year lifespan…

At the same duty cycle, the 5 year warranty covers 5.479×103 hours. Huh.

The URL at the bottom leads to some general info, but nothing you didn’t know already.

It works well enough, but at $35 it’s really a capital investment that I suspect will never actually pay for itself…