ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
UL 508A SPACING
by ale348 - 03/29/24 01:09 AM
Increasing demand factors in residential
by tortuga - 03/28/24 05:57 PM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
Do we need grounding?
by NORCAL - 03/19/24 05:11 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
1 members (ale348), 302 guests, and 14 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 3 of 4 1 2 3 4
Joined: Oct 2000
Posts: 4,116
Likes: 4
Member
.... still running ....

Bill
[Linked Image]


Bill
Joined: Aug 2002
Posts: 1,081
T
Member
That must be a perennial bulb. [Linked Image]

Joined: Jul 2003
Posts: 394
B
Member
I seen some technical information from G E that showed live verses output of incadesent bulbs for various percentages of voltage above and below design voltages. It is amazing how much the life changes. I attended a church where a weekly job for the pastor was replacing burned out exit light bulbs. Several a week. I replaced all the 7 watt 120 volt ones with 11 watt 130 volt bulbs and the failure rate went down to a couple a year.

Joined: May 2002
Posts: 1,716
R
Member
Still running.

Hope you don't mind Bill. [Linked Image]

Roger

Joined: Oct 2000
Posts: 4,116
Likes: 4
Member
Thanks Roger!

We've been 'watching' this Bulb for almost 5 years ourselves now!

Time flies, doesn't it?

[Linked Image]
Bill


Bill
Joined: Mar 2005
Posts: 1,803
Member
The carbon filaments for bulbs were made from strips of carbonised bamboo.

Ah so, grasshopper, many Hans make light work! [Linked Image]


Wood work but can't!
Joined: May 2002
Posts: 1,716
R
Member
Bill,
Quote
Time flies, doesn't it?

It certainly does.

Roger

Joined: Dec 2005
Posts: 869
Likes: 4
R
Member
Great thread Bill.

Good it got bumped up.

Never read this one yet at ECN.

I'm aware of the fireststion lamp, amazing 100 years of service.

I'm into meters a lot and about 15 of my in house lamps have hour meters on them.

Most lamps last around 800 hours out of the claimed 1000 hrs.
Some so called long life lamps are actually rated for 250 Volts! while our nominal voltage is 230 - 235 V.
These appear to go for around 2300 hrs.
Certainly the voltage is critical for the life of the lamp, overvoltage is fatal undervoltage even 10 or 15 volts makes the bulbs last a lot longer although with less light output.


My outside lights which are on all night via a timeclock last around 8000 hrs with standard lightbulbs. These have a 1 N 5408 diode in series in the fitting to halfwave the voltage. and from the control point a 200 watt lamp in series to smooth in inrush peak. replacement around every 2 years, sometimes longer. the 3 bulbs used are 40 watts each.
Vibration is not good for filament lamps as are enclosed fittings where excess heat will cause early faillure.

Then the inrush current at switch on is hard on the filament too. most lamps tend to fail at switch on with the usual "ping"

I guess the US 110 or 130 Volt lamps last a lot longer due to the thicker filaments ?
or they are claimed to last 1000 hrs too ??

I got some of the CFL's too which have done 12349 hrs out of the claimed 15000 hrs. These are still going strong.


The product of rotation, excitation and flux produces electricty.
Joined: Mar 2005
Posts: 1,803
Member
'Inrush current' isn't be a serious problem for filaments until they get degraded with use. All lamp filaments lose material at the high temperatures of service- it migrates off the filament as metal or carbon vapor and can often be seen on an old bulb near the base, where the glass is coolest. Inert Gas filling reduces the migration of material, [as does use of a thicker wire of course]. 'Vacuum' bulbs are obsolete simply because gas filled ones last longer.

The 'inrush' "problem" is supposed to be worse with metal filaments, as resistance increases with temperature = high amps at start. The speed of the temperature rise in a modern bulb is such that this resistive effect is of little consequence, and there is negligable temperature overshoot. Failure may also be due to minute dislocations or faults growing in the filament material with each cycle of on/off, a function of material quality,
[ie 'They last longer if you leave them on'].
Tungstan wire is drawn from powder-metallurgy formed slugs- the material is never melted, so the wire is a 'welded' material. Carbon filaments were grown by a plant and so suffer from biological variability. Interestingly, carbon filaments had a negative resistance curve, the resistance falling with temperature rise. They still failed eventually - often by blacking out the glass surface with so much soot that the light couldn't get out! [Linked Image]
The '100 year' carbon bulb is running at a very low filament temperature. This has slowed migration to a negligable level, but eventually.....

Alan


Wood work but can't!
Joined: Feb 2006
Posts: 144
N
Member
side note, sorry for straying, I think this is really cool. Personally, I like that old fashoned orange glow. I have tons of little 11 watt exit sign bulbs in lamps all throughout my house. I was at a furniture store once that had these neat bulbs in all of their lamps for sale. They are kinda hard to describe, but, it almost looked like they had 2 filaments. They intersected in an almost heart shaped pattern, and glowed that orange like color. The woman running the store didn't know where they had gotten them, and I didn't feel like buying a $200.00 lamp just to get a bulb. Am I crazy or has anyone else ever seen anything like this? An "Edison" bulb of sorts. Any info appreciated.


They had a party for the bulb when it had a milestone birthday. I bet 1,000,000 hours (roughly) would be a neat excuse to have a big town party. I know that I am definately going to be sad when/if this ever burns out. It's a neat landmark to have. The worlds oldest lightbulb. kinda cool [Linked Image]

Page 3 of 4 1 2 3 4

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5