Author Topic: Why do incandescent light bulbs have a frequency rating?  (Read 15897 times)

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Offline helius

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #25 on: January 12, 2019, 08:04:29 pm »
[I have a computer which has the strangest problem. Most computers have problems when they get too hot but I have a computer that hangs in cold winter weather. It took me a while to figure it out but now I just heat it and the easiest way is with a small incandescent light bulb.
This can be a condensation problem. Not only does it cause malfunctions but can cause increased corrosion over time. For network infrastructure there are specific switches that disable power-saving modes, just to increase the operating temperature in cold climates.

...bulbs with halogen capsules in them are readily available and behave exactly like a traditional bulb with slightly higher efficiency.
Halogens must reach their operating temperature, which is higher than an incandescent, to regenerate the emissive material. When operated below this temperature, for instance by being dimmed or only turned on briefly, they become darkened and fail. By contrast, incandescent bulbs last longer when dimmed. So far from behaving "exactly like a traditional bulb", they behave exactly opposite to one.
« Last Edit: January 12, 2019, 08:06:11 pm by helius »
 
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Offline james_s

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #26 on: January 13, 2019, 06:04:30 am »
...bulbs with halogen capsules in them are readily available and behave exactly like a traditional bulb with slightly higher efficiency.
Halogens must reach their operating temperature, which is higher than an incandescent, to regenerate the emissive material. When operated below this temperature, for instance by being dimmed or only turned on briefly, they become darkened and fail. By contrast, incandescent bulbs last longer when dimmed. So far from behaving "exactly like a traditional bulb", they behave exactly opposite to one.
[/quote]


While this can be an issue, in practice I have not found it to be a problem. For about 8 years I had some GE Halogena lamps in the light above the dining table because that light is on a dimmer and was only rarely used at full brightness. I never had one of those lamps darken or fail, I only replaced them when sufficiently attractive dimmable LED bulbs became available. This is real world actual experience I speak from here, not speculation.

I did once have the tubular halogen bulb in one of those torchier lamps that were popular in the 90s blacken but that happened when someone left it on all night and the next day at a very dim glow such that it wasn't even noticed until it got turned up the next evening. The halogen capsules in bulbs designed to replace standard incandescent lamps are hard glass rather than quartz and do not run as hot as typical quartz halogen lamps. They are not as efficient or long lived either, however they are modestly better than standard incandescent on both counts.
 

Offline james_s

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #27 on: January 13, 2019, 06:19:29 am »
... you may have to look just a little bit harder they are available.

I don't have to look hard at all as I have a stock to last me the rest of my life and I travel to China regularly so I could always get some more there.

of course I expect the tree-hugging SJW to condemn my lack of solidarity.  The same ones who drive huge SUVs and use ten times more energy than I do. You can't win for losing.


Do what you want, it's not about you. Fortunately most people are less stubborn than you are so the ban worked exactly as intended. LED bulb adoption picked up rapidly and prices plummeted, goal accomplished. The fact that a few people insist on being contrary or are so resistant to change, or so bent on making some kind of political point that they hoard a lifetime of bulbs is of no real consequence, the rest of us can now enjoy low cost, long life, high efficiency lighting and the dramatically lower average energy use by lighting that has taken place over the past 20-30 years gives us lower cost energy and cleaner air.

If someone is so intent on clinging to incandescent lighting they are free to do so, as you point out it isn't particularly hard to jump through the hoops required to do it. All that matters is that a significant portion of the population is persuaded into trying something new. People overall are notoriously resistant to change.
 

Offline spec

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #28 on: January 13, 2019, 09:13:29 am »
We still have some halogen downlighters in the kitchen, most are now LED.  Can anyone explain why it is that when a halogen bulb fails it trips the fuse, not just once, but every time.
 

Offline soldar

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #29 on: January 13, 2019, 10:59:45 am »
Can anyone explain why it is that when a halogen bulb fails it trips the fuse, not just once, but every time.
I suspect when the filament breaks it starts an arc which eats away the rest of the filament and provides almost no resistance and the current skyrockets.
All my posts are made with 100% recycled electrons and bare traces of grey matter.
 
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Online Ian.M

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #30 on: January 13, 2019, 11:29:30 am »
Traditional mains voltage incandescents often had a fuse in one of the filament leadouts inside the hollow glass stem supporting the filament support wires to break the circuit if the bulb arced internally when its filament failed.  In combination with an appropriately rated supply fuse or breaker this provided discrimination such that a blown bulb would NOT usually trip the circuit feeding other parallel bulbs.   However small capsule halogen bulbs have no space for such a fuse. 

You may still find a fuse in the stem in some better quality incandescent replacement bulbs that have a conventional glass envelope with an inner halogen capsule, but it appears to be commonly omitted from the budget ones.
 
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Offline james_s

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #31 on: January 13, 2019, 06:25:14 pm »
The fuse is omitted from a lot of cheap conventional incandescent lamps too, although I don't recall having a failed bulb trip the breaker I have seen the lead in wires melt down to stubs. That surprise flash and pop is something I really don't miss, always seemed to happen when I'd walk into a dark room late at night half asleep and turn on the light.
 

Online Ian.M

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #32 on: January 13, 2019, 06:53:32 pm »
Ah the joys of cheap Bulgarian incandescent bulbs!  No fuse, and even odds of tripping the breaker when they blew.  Roughly one time in ten, they'd blow the glass out of the base with a loud bang, showering the area with broken guts as well as tripping the breaker, and if they did that, often as not the remains of the base would jam in the bulbholder. 

Then there was the retrofit project to replace the halogen downlighter bulbs with LEDs.  It wasn't too successful as the contractors used cheap LED downlighter bulbs with a tendency to explode, leaving live wires and the remains of the circuit board dangling out of the ceiling.  After a spate of failures in the first couple of months, one of the ones over the CEO's desk blew while he was under it.   Legal got the contractors back in to replace them all with western branded bulbs at their expense over the weekend!
 

Offline Mazo

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #33 on: January 14, 2019, 12:07:59 am »
Ah the joys of cheap Bulgarian incandescent bulbs!  No fuse, and even odds of tripping the breaker when they blew.  Roughly one time in ten, they'd blow the glass out of the base with a loud bang, showering the area with broken guts as well as tripping the breaker, and if they did that, often as not the remains of the base would jam in the bulbholder.
As a fellow Bulgarian I should confirm that our incandescent bulbs do burst often when they die so if you still have some of those,be prepared.Also get pliers to unjam the holder :) The good news is we have moved on to manufacture of LED bulbs that are cheap but TBH they rarely last more than around 2years
 

Offline cdev

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #34 on: January 14, 2019, 03:12:13 am »
Is it true that in some Eastern European countries people were often so poor (and electricity so unreliable) that some families only had a single light bulb which they moved around from one socket to another? 

Also I was told that condoms there were in such short supply that they were often washed out, dried and reused.

I don't think this was a joke but it was second hand information. (Hearsay)
"What the large print giveth, the small print taketh away."
 

Offline james_s

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #35 on: January 14, 2019, 06:26:45 am »
I remember going to a house party many years ago at a dumpy place rented by a bunch of guys I knew. There were so few working light bulbs that for much of the evening I took one with me from room to room. Seems unlikely people would be too poor to buy light bulbs but still able to pay for electricity to run them. In the case of the place I mention it was mostly a matter of people being far too lazy for their own good.
 

Offline helius

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #36 on: January 14, 2019, 07:23:03 am »
In many old films you can see people turning lights on and off by twisting the bulbs directly. You could certainly be able to afford bulbs (they were always cheap) but unable to afford to install enough switches to control each one individually.
 

Offline Mazo

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #37 on: January 14, 2019, 01:20:39 pm »
Is it true that in some Eastern European countries people were often so poor (and electricity so unreliable) that some families only had a single light bulb which they moved around from one socket to another? 

Also I was told that condoms there were in such short supply that they were often washed out, dried and reused.

I don't think this was a joke but it was second hand information. (Hearsay)
No problem with getting light bulbs in socialist times or ever.There was a time that electricity was available only in certain times of the day, but that was more of a political stunt (we produce more electricity than we use since the 1970s at least....).As far as condoms go they were common but AFAIK weren't known for durability and were far too thick so they weren't really popular.I think we went offtopic though  :-DD
 

Offline james_s

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #38 on: January 14, 2019, 04:34:40 pm »
In many old films you can see people turning lights on and off by twisting the bulbs directly. You could certainly be able to afford bulbs (they were always cheap) but unable to afford to install enough switches to control each one individually.

Even as recently as the late 80s there was an outbuilding on my grandmother's property where the light was controlled by screwing the bulb in. I think that was reasonably common in more utilitarian settings like sheds.
 

Offline Taalica

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #39 on: January 18, 2022, 11:50:57 am »
It seems to me that on this issue only people will help you who are well versed in the electrics. I used to trust only professionals after my light bulb burned down in the car.
 

Offline Alti

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Re: Why do incandescent light bulbs have a frequency rating?
« Reply #40 on: January 18, 2022, 08:19:22 pm »
We still have some halogen downlighters in the kitchen, most are now LED. Can anyone explain why it is that when a halogen bulb fails it trips the fuse, not just once, but every time.
I do not think this has anything to do with halogen design. Every incandescent bulb ends its life by drawing an arc across the filament. It is physics, if you break the circuit where current flows then the inductance of the circuit is going to kick back. Works like a charm in my car, every single time. Sometimes the arc extinguishes itself fast enough and sometimes not, leading to excessive currents.
By coincidence it happened that you only use halogen and that is your observation. You should not use incandescents without suitable protection because, even though house wiring protection is provided, its job is not to extinguish arcs in cheap bulbs that lack the built-in fuse.
 


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