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OT: expensive decorative lamps that won't light, for no obvious reason
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William Sommerwerck
Dec 14, 2014, 10:38:02 AM12/14/14
to
A few months back I got around to cleaning my condo's ceiling fixtures. These
use tiny bulbs with miniature Edison bases. Some had burned out.
Some bulbs had behaved oddly, going "dead", but responding to being tightened.
So I decided to examine all the non-lighting bulbs closely.
https://en.wikipedia.org/wiki/Edison_screw
All but one were burned out. The other showed no visible filament break, but
my ohmeter said "open". I put it aside and tried periodically to fix it.
(These lamps cost about a dollar apiece.) Though I unsoldered and resoldered
the base and thread connections -- and confirmed there really were wires going
to them -- there were no visible signs of damage.
This morning I gave one last shot. This time I twisted off the brass base,
this action apparently pulling out the broken part of the wire going to the
tip.
Using a magnifier, I could see that wire "ending" about halfway along the
internal glass stem. It appears the wire had (or developed) a high-resistance
section, which burned open the wire.
The same thing happened to the bottom Calrod unit in my oven several years
back, so I shouldn't have been surprised.
PS: I have plenty of things to keep my busy, but I enjoy Show and Tell.
use tiny bulbs with miniature Edison bases. Some had burned out.
Some bulbs had behaved oddly, going "dead", but responding to being tightened.
So I decided to examine all the non-lighting bulbs closely.
https://en.wikipedia.org/wiki/Edison_screw
All but one were burned out. The other showed no visible filament break, but
my ohmeter said "open". I put it aside and tried periodically to fix it.
(These lamps cost about a dollar apiece.) Though I unsoldered and resoldered
the base and thread connections -- and confirmed there really were wires going
to them -- there were no visible signs of damage.
This morning I gave one last shot. This time I twisted off the brass base,
this action apparently pulling out the broken part of the wire going to the
tip.
Using a magnifier, I could see that wire "ending" about halfway along the
internal glass stem. It appears the wire had (or developed) a high-resistance
section, which burned open the wire.
The same thing happened to the bottom Calrod unit in my oven several years
back, so I shouldn't have been surprised.
PS: I have plenty of things to keep my busy, but I enjoy Show and Tell.
Grant
Dec 14, 2014, 4:23:39 PM12/14/14
to
On Sun, 14 Dec 2014 07:37:51 -0800, "William Sommerwerck" <grizzle...@comcast.net> wrote:
>A few months back I got around to cleaning my condo's ceiling fixtures. These
>use tiny bulbs with miniature Edison bases. Some had burned out.
>
>Some bulbs had behaved oddly, going "dead", but responding to being tightened.
>So I decided to examine all the non-lighting bulbs closely.
>
>https://en.wikipedia.org/wiki/Edison_screw
>
>All but one were burned out. The other showed no visible filament break, but
>my ohmeter said "open". I put it aside and tried periodically to fix it.
>(These lamps cost about a dollar apiece.) Though I unsoldered and resoldered
>the base and thread connections -- and confirmed there really were wires going
>to them -- there were no visible signs of damage.
>
>This morning I gave one last shot. This time I twisted off the brass base,
>this action apparently pulling out the broken part of the wire going to the
>tip.
>
>Using a magnifier, I could see that wire "ending" about halfway along the
>internal glass stem. It appears the wire had (or developed) a high-resistance
>section, which burned open the wire.
Looks like you are describing the lamp's fuse?
>A few months back I got around to cleaning my condo's ceiling fixtures. These
>use tiny bulbs with miniature Edison bases. Some had burned out.
>
>Some bulbs had behaved oddly, going "dead", but responding to being tightened.
>So I decided to examine all the non-lighting bulbs closely.
>
>https://en.wikipedia.org/wiki/Edison_screw
>
>All but one were burned out. The other showed no visible filament break, but
>my ohmeter said "open". I put it aside and tried periodically to fix it.
>(These lamps cost about a dollar apiece.) Though I unsoldered and resoldered
>the base and thread connections -- and confirmed there really were wires going
>to them -- there were no visible signs of damage.
>
>This morning I gave one last shot. This time I twisted off the brass base,
>this action apparently pulling out the broken part of the wire going to the
>tip.
>
>Using a magnifier, I could see that wire "ending" about halfway along the
>internal glass stem. It appears the wire had (or developed) a high-resistance
>section, which burned open the wire.
Grant.
William Sommerwerck
Dec 14, 2014, 6:53:14 PM12/14/14
to
"Grant" wrote in message news:rtvr8aplg64qn33fg...@4ax.com...
> Looks like you are describing the lamp's fuse?
I didn't know they had them. I assumed it was a sample defect.
> Looks like you are describing the lamp's fuse?
John Robertson
Dec 15, 2014, 2:17:26 PM12/15/14
to
intentionally added to the internal leads in case the filament shorted
inside the bulb...
Can't find anything in quick online searches though, and I don't have a
line voltage light bulb design specs book.
John :-#(#
--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
William Sommerwerck
Dec 15, 2014, 4:08:54 PM12/15/14
to
"John Robertson" wrote in message
news:QOednSgxFYRfrhLJ...@giganews.com...
awfully good at finding stuff.) This bulb obviously had a defective fuse. You
learn something new every day.
http://donklipstein.com/bulb1.html
news:QOednSgxFYRfrhLJ...@giganews.com...
On 12/14/2014, 3:53 PM, William Sommerwerck wrote:
> "Grant" wrote in message
> news:rtvr8aplg64qn33fg...@4ax.com...
>>> Looks like you are describing the lamp's fuse?
>> I didn't know they had them. I assumed it was a sample defect.
> I thought I recalled seeing something about there being a weak spot
> intentionally added to the internal leads in case the filament shorted
> inside the bulb...
> Can't find anything in quick online searches though, and I don't have
> a line voltage light bulb design specs book.
Here you go. Scroll down to "Why burnout is sometimes so spectacular". (I'm
> "Grant" wrote in message
> news:rtvr8aplg64qn33fg...@4ax.com...
>>> Looks like you are describing the lamp's fuse?
>> I didn't know they had them. I assumed it was a sample defect.
> I thought I recalled seeing something about there being a weak spot
> intentionally added to the internal leads in case the filament shorted
> inside the bulb...
> Can't find anything in quick online searches though, and I don't have
> a line voltage light bulb design specs book.
awfully good at finding stuff.) This bulb obviously had a defective fuse. You
learn something new every day.
http://donklipstein.com/bulb1.html
John Robertson
Dec 15, 2014, 5:40:07 PM12/15/14
to
Thanks!
Gee, an Internet light bulb database, who'd have guessed (OK, I should
have known better), and why didn't the search engines turn that up in my
earlier searches?
John :-#)#
William Sommerwerck
Dec 15, 2014, 6:25:21 PM12/15/14
to
"John Robertson" wrote in message
news:zPydnVSczNff_hLJ...@giganews.com...
> Gee, an Internet light bulb database, who'd have guessed
> (OK, I should have known better), and why didn't the search
> engines turn that up in my earlier searches?
John Robertson
Dec 16, 2014, 2:05:53 AM12/16/14
to
I found some interesting reading for "incandescent lamp lead fuse" - one
from some retired electricians writing in 1922 about early shipboard
lighting where fuses hadn't been considered...almost set the ship on fire!
Fourth down titled: Electric Fuses - Page 4 - Google Books Result
https://books.google.ca/books?id=8r-XrMvGm4YC&pg=PA4&lpg=PA4&dq=incandescent+lamp+lead+fuse&source=bl&ots=3cty9MSMHW&sig=qYmMtrc3__Z-dbQCbTYCSyDqcZo&hl=en&sa=X&ei=29ePVJC8Csu1ogSVzYDoDQ&ved=0CEIQ6AEwCA#v=onepage&q=incandescent%20lamp%20lead%20fuse&f=false
or a tiny custom URL:
http://tinyurl.com/IncandescentLampFuse
hrho...@sbcglobal.net
Dec 20, 2014, 11:38:30 PM12/20/14
to
I repair donated for recycling incandescent miniature Christmas lights and donate to the local Goodwill. A couple of strings that I have gotten have every single miniature light bulb burned out. Apparently the owner/user never replaced the burned out bulbs, and as the voltage across the lit bulbs increased due to the shunts on the filaments of the burned-out bulbs, there was an escalating burn-out. It must have made a spectacular flash at the final failure<g>.
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