While they are dying out, you can still find incandescent bulbs. While these were once totally common, they’ve been largely replaced by LEDs and other lighting technology. However, you still see a number of them in special applications or older gear. If you are above a certain age, you might be surprised that youngsters may have never seen a standard incandescent lightbulb. Even so, the new bulbs are compatible with the old ones, so — mechanically, at least — the bulbs don’t look different on the outside.
It has been known for a long time that passing a current through a wire creates a glow. The problem is, the wire — the filament — would burn up quickly. The answer would be a combination of the right filament material and using an evacuated bulb to prevent the filament degrading. But it took over a century to get a commercially successful lightbulb.
We were all taught in school that Thomas Edison invented the light bulb, but the truth is much more complicated. You can go back to 1761 when Ebenezer Kinnersley first caused a wire to glow. Of course, wires would quickly burn up in the air. By the early 19th century, limelight was fairly common in theaters. Limelight — also known as the Drummond light — heated a piece of calcium oxide using a gas torch — not electric, but technically incandescence. Ships at sea and forts in the U.S. Civil War used limelights to illuminate targets and, supposedly, to blind enemy troops at night. Check out the video below to see what a limelight looks like.
Sir Humphry Davy demonstrated a dim, impractical light that used a huge battery and a thin strip of platinum. More practical was Davy’s electric arc lamp, which, after being refined by others, became common in some applications.
Arc lights had issues, though. They hissed and flickered. The carbon rods emitted carbon monoxide and ultraviolet light. They were extremely harsh and bright, and the rods burned up quickly. Everyone knew a better light bulb would be a winner, but no one knew how to create it.
Getting Closer
Starting around 1835, there were many experiments and demonstrations, but none of them really caught on. A Belgian, Marcellin Jobard, was on the right track in 1838 with a lightbulb in a vacuum with a carbon filament, but nothing really came of it. He also came up with what amounts to early emojis, but that took a long time to catch on, too.
Since platinum has a high melting point, it was a popular filament candidate. In the 1840s and 1870s, many inventors used platinum or carbon with varying degrees of success. During that same time period, there were many patents and demonstrations, but none were successfully commercialized. However, a Russian named Alexander Lodygin did patent a working bulb with carbon rods in nitrogen gas.
It isn’t clear if Henry Woodward and Mathew Evans knew of the Russian patent. In 1874, they filed a Canadian patent for a similar bulb. Ultimately, they failed to commercialize it, but they sold their patent to Thomas Edison.
Edison
Edison got serious about electric lighting in 1878. He experimented with different carbonized materials and platinum but finally settled on carbon fed by platinum wires. Using carbonized threads resulted in a bulb that lasted just over 13 hours. However, he would discover that carbonized bamboo could last 1200 hours. You can see one of the oldest surviving Edison bulbs at the Port Huron Museum and in the video below.
Many people worked on the problem throughout the 1800s. Edison arrived at a practical solution and had the mechanism in place to exploit it. However, others had light bulb patents. Albon Man and William Sawyer had bulbs that didn’t last as long as Edison’s but formed the basis for the United States Electric Lighting Company. That company’s chief engineer was Hiram Maxim, a name familiar to most ham radio operators, but this particular Hiram Maxim was the famous ham radio operator’s father.
The elder Maxim is one of several people who claimed they had actually invented the incandescent light before Edison. The courts eventually decided that some of Edison’s claims were preempted by William Sawyer’s patents, but that Edison still had other valid patent claims.
Modern Types
These early bulbs had little in common with modern bulbs. The inside of the bulb had to have very little oxygen and moisture, or the filament would oxidize or burn out. Initially, mercury vapor pumps and phosphoric anhydride were used, but this added expense to bulbs. Arturo Malignani found that red phosphorus would allow for a drier vacuum with cheaper pumps. Edison was quick to buy the patent.
However, Lodygin and others were on the right track, and using a metal filament and an inert gas to replace the oxygen would be more effective. This prevents the filament from burning and also reduces the evaporation of the filament. (See the video below if you want to see the effect of air on a tungsten filament.) He invented a process for forming thin metal filaments and sold the patent to General Electric in 1902.
The truly modern bulb is the result of a 1904 invention by Sándor Just and Franjo Hanaman. They created a tungsten filament that worked better in an argon or nitrogen atmosphere. The Hungarian company Tungsram sold these, and they could practically pass for a modern clear-glass bulb.
A modern bulb has a glass envelope and a tungsten filament, although they add a few impurities to increase the filament life. The bulb contains a low pressure of a gas like argon, nitrogen, krypton, or xenon. Modern glass bulbs are either clear or coated with kaolin clay from the inside. Some bulbs have pigments to change color or different glass to produce different colors. Bulbs used for heating sometimes have special glass or even fused quartz.
Real World Considerations
Light bulbs are one of those circuit elements we pretend are perfect, but they aren’t. Tungsten filaments have a low resistance when cold, which causes a bulb to draw a lot of current when it first turns on. As the filament gets hot, the resistance goes up, and the current goes down. Oddly enough, carbon filaments have the opposite problem. They draw more power as they get hot, which also makes them sensitive to power surges, since if they get hot, they draw more current, which causes them to draw even more current, which makes them even hotter, and the cycle repeats.
In high-reliability circuits, designers often highly derate a bulb’s specifications to get a dimmer light that lasts longer. A 5% reduction in voltage will roughly double a bulb’s lifetime but also make it about 16% dimmer. Some will also pass a small current through the bulb even when it is off to keep the filament warm. This reduces the current draw and heating associated with turning on a cold filament.
The other big problem with incandescent lights is that they are relatively inefficient since most of the energy produces heat and infrared light. A typical bulb is around 5% efficient in terms of visible light, and the best halogens come in around 10%.
Of course, this inefficiency is why there’s been a move to ban incandescent bulbs in favor of LEDs, fluorescents, and other technologies. LED lights, in contrast, can reach 30-40% efficiency. Still more light than heat, but almost an order of magnitude more efficient than plain-old incandescents.
So Much More
There’s a lot more to learn about light bulbs. In 1885, the U.S. had an estimated 300,000 carbon filament bulbs. By 1914, there were 88.5 million. In 1945, the market was around 795 million. When you deal with that kind of scale there are many innovations both in the technology and the machinery used to build them. Want to see how lightbulbs were made? Check out the video below.
We’ve talked about the early lighting market and one of its pioneers, Lewis Latimer, a few years ago. We’ve looked at the checkered history many times.
Featured image: “Yellow Bulb” by [Daniel Reche]
I just threw away (“recycled”) another couple of LED bulbs that died. So much for “Lasts 10+ years!”. Let’s compare the impact of LED lighting on Mother Earth…
Incandescent Bulb components:
1) Glass
2) Metals (Aluminum, Steel, Tungsten)
LED Bulb components:
1) Plastic
2) FR-4 or similar circuit board (Epoxy, Fiberglass)
3) Electronics (capacitors, diodes (LEDs/rectifiers), doped-silicon ICs)
Which of these two devices is less harmful/polluting to the landfill they’ll end up in?
Turn up nuclear power (ideally, breeder reactors) and bring back the option that pollutes far less.
The trash aspect of a lightbulb is negligible either way. A few ounces of trash waste amortized over many years is essentially zero. Conversely, the energy needs of an incandescent light bulb are something like 1lb of carbon dioxide per HOUR. So until some future time when electricity generation produces no carbon dioxide, energy consumption is the only waste metric that matters for lightbulbs.
Plants love CO2. Carbon dioxide is not a problem. Our impact is negligible. A hotter, wetter planet means we have lots of food to eat and don’t freeze to death.
A hotter planet doesn’t change how many hours of sunlight a region gets. Growing seasons would remain the same, and tropical plants such as coffee and cacao wouldn’t be able to grow in regions with less sunlight. Meaning that they’ll be forced into extinction in a warmer climate.
But good job regurgitating that climate change denialism drek.
Wow, found one in the wild
However most light is needed in the winter when the “waste” energy contributes to the heating (At least in the domestic environment)…
But a lot of energy goes into the production of them also.
I’ve just had two new LED bulbs fail within a week. I suspect they’re a diff batch as others I’ve had have been ok, but still…
“A 5% reduction in voltage will roughly double a bulb’s lifetime but also make it about 16% dimmer.” Which is part of the reason the “1000 hour cartel” idea isn’t quite logical; a longer-lasting bulb of the same brightness would cost enough in extra energy consumption that changing them more often made a fair amount of sense.
“30-40% efficiency. Still more light than heat,” Should be more heat than light if that’s the case.
Interestingly, as far as I remember it tends to be that automotive incandescent bulbs are vacuum type, while home use bulbs are the inert gas filled as you mentioned. Most likely argon. Oh, and halogen bulbs are just incandescent bulbs except run at a higher power density made up for by the boost in lifetime from the halogen cycle that mostly returns tungsten to the filament.
Now some really interesting ones were nernst lamps and the carbon button lamp; the first one uses a ceramic that doesn’t get oxidized away (so that it beats carbon for efficiency, although apparently not necessarily incandescent despite the greater temperature). Though the limelight is debated, I think in general the idea with them is both a bit similar – very very high temperature oxides don’t oxidize away in air and make a fairly nice color temperature. https://hackaday.com/2020/06/16/retrotechtacular-the-nernst-lamp/
The second, the carbon button, was an odd Tesla idea that I’m not entirely sure if anyone’s put full effort into finding the limits of – not that it’s great, but it’s interesting at least. I’d like to see if a variation on it may be made a little like a carbon arc lamp, but without the second carbon electrode and the adjustment mechanism. If so, would be nice to get an (inefficient) high power high intensity discharge out of it. May be unavoidable that the power density can’t get high enough while keeping the lifetime up; there’s a reason we have short-arc xenon now.
The best LEDs are about 75% efficient. http://donklipstein.com/led.html
Its interesting how insular communities can be. In my circles ‘Hiram Maxim’ is the inventor of the machine gun and no one’s heard of Hiram Percy Maxim, who is, apparently, famous among radio enthusiasts (who have probably never heard of his father;)
Most amateur radio enthusiasts are aware of the family heritage, but most don’t choose to celebrate that part of their legacy. Your circles probably would be aware also of Hiram Percy’s invention of the firearm sound suppressor (silencer), which continues to present day in the form of industrial noise control.
Wait so one of them is famous for inventing the machine gun, the other is famous for radio, but the radio one also invented the firearm silencer? Yeah that is confusing lol
The Edison story is mostly an American thing, I think. It’s their hero.
Here in Germany, for a long time we considered Heinrich Göbel as the inventor.
Also, there are indications that the ancient egypts had primtive glowing lamps already.
Thinking of the ancient Bagdad battery, it’s a possibility.
In practice, though, the light bulb likely had many inventors throughout human history.
The books of history are under constant contruction.
Science itself is just a momentary snapshot and ever changing.
So let’s relax. ^_^
Sir Joseph Wilson Swan was knighted by King Edward VII for inventing the light bulb, unfortunately he wasn’t an American either and is therefore as irrelevant as Heinrich Göbel.
I’m surprised there was no mention of Joseph Swan the English physicist who is also credited with developing incandescent lighting independently from Edison. He went into partnership with Edison forming the Edison & Swan United Electric Light Company, commonly known as “Ediswan”. It’s all in Wikipedia.
It’s pretty much guaranteed that a US-centric article wouldn’t mention any British inventors ;-) ! I wouldn’t be surprised if most Americans still thought Blue Flame had the World Land Speed record (in fact it’s been held by the UK since the early 1980s)!
Hiram Maxim was British…
Ha! Touché, I didn’t know! From a British perspective though, we’re always trying to fight the corner for Swann, because I understand there was some kind of joint patent for incandescent light bulbs at least with regard to them being sold in the UK.
-cheers!
Appliance bulbs, such as those in an oven, are (often?) incandescent.
For a while “Rough Service” bulbs existed as incandescent after regular incandescent bulbs were NLA.
I tried using an LED bulb in my garage door opener (GDO), a typical rough service application, but it gave off RFI which prevented the GDO from receiving the signal from the car remotes. The current LED in the GDO does not interfere.
Many of the older LED bulbs used switch mode power supplies and they tended to produce a lot of RFI. Now that we have high voltage, multi die LEDs, most bulbs use linear power supplies. That makes them RF quiet as long as they aren’t used on a dimmer.
So why was Latimer selected for an article, out of all these colorful inventors? :)
Actually, I originally drafted this with blow by blow of everyone I could find and it was so long I was going to have to do a two parter. Then I realized we had covered much of this earlier so I included a link, deleted a bunch, and put in the line about many others. A number of people mentioned are not American but I suppose everyone sees what they want to see. Regardless, if you really want to see the details of everybody who had a potential incandescent lamp invention just before and just after Edison, the other article linked from a few years ago does a great job of covering that.
i’m an incandescent hold out- i have a stick pile of them- but i also have dimmers and i almost never have my bulbs on 100%- i’ve tried to lay out my lighting to able to be bright at 75%. because of how low i run them that last a really really long time. I have one lamp that’s on every evening from sunset to 10:00 and it’s over 15 years old
So you don’t care about the extra electricity costs?
I once toured a chem lab that had a large glove box maintaining an argon atmosphere. There was a little incandescent flashlight bulb in one corner with the glass broken off.
When I asked about it, they said “That’s hooked up to an alarm. If oxygen starts getting into the box, the filament burns through in a few minutes, and the alarm goes off.”
Try THAT with an LED bulb.
When Edison was still trying to brute force the filament material to have lamps that last more than few minutes, The Italian Alessandro Cruto was already selling 1000 hrs lamps in large quantities, as completely industrialised products.
Saying that edison invented the incandescent lamp is false and stupid as saying that Jobs invented the smartphone o Bell invented the telephone. Only Americans can believe that….