# Found an induction bulb in a retail store



## PhotonWrangler (Jun 21, 2019)

I walked into an office supply store today - their name rhymes with Maples - looking for some ink cartridges for a pen. While browsing the aisles I was startled to see a couple of induction bulbs for sale - a 60w equivalent and a 100w equivalent. The package calls it a "Acandescent" lamp. They're notably less efficient than the LED bulbs that were right next to them, but I've never owned an induction bulb before so I snapped up a 60w version.

Rated color temperature is 2700k. While it lights up right away, there is a 20 second or so warmup period during which it gets brighter and a little whiter. The package states that the 800 lumen rating is valid when operating the bulb base down, with a difference of 5% when operating base up. I'm assuming this means 5% dimmer. On a positive note it's rated for fully enclosed fixtures.

The globe gets pretty warm pretty quickly, but the base remained notably cooler. I plan to try to remove the globe so I can see the guts of the bulb. I also plan to check for 60/120hz flicker and look at the lamp's RF emissions on a spectrum analyzer. I suspect it's going to be pretty noisy.


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## FLfrk (Jun 21, 2019)

Induction? What does that even mean? Sounds like a full blown science project, I like it!


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## PhotonWrangler (Jun 21, 2019)

It uses a strong electromagnetic field to excite mercury, causing it to glow with UV light, which in turn excites a phosphor. It's similar to a fluorescent lamp except in the way that the mercury is energized.

They're also called electrodeless lamps as they don't need electrodes inside the glass envelope like fluorescent lamps do, making for a better seal.

Here's a unique example of the induction lighting principle. Science! 

And here's another good description of induction lamps including a partial teardown of a Philips bulb showing the inductor/antenna.

**Edit**

I've just tested it with a shortwave radio and I pick up a signal at 2.650mhz from the bulb that's modulated with 120hz hum.


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## lightfooted (Jun 22, 2019)

I would guess that some business in town must make use of them for outdoor lighting or something, maybe a small warehouse. They probably don't want to replace the fixtures yet. Interesting find for sure.


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## yuandrew (Jun 23, 2019)

They were announced a few years back as the "Finally" light bulb by Boston, Massachusetts based startup Lucidity Lights. Hadn't heard of them being on the retail store shelves until now. Not much info on their website though, just a signup for announcements

http://finallybulbs.com/

https://www.candlepowerforums.com/vb/showthread.php?400842


They basically work in a similar manner to a typical fluorescent lamp except instead of using electrodes at the ends of a tube, they use RF induction to excite the gasses. Lucidity touted them as being new but the technology has been around for while already; years ago (early to mid 90's), GE marked an induction lamp in an R-30 reflector shape called the Genura and more recently (2006 ?) Sylvania had a lamp called the Dura-One


An old experiment I did

https://youtu.be/cZctmAiDxvk?t=61


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## PhotonWrangler (Jun 24, 2019)

Thanks Yuandrew. Yes it's the "Finally" bulb. Apparently they've been sitting on their shelves for awhile; there was a layer of dust on top of the cartons.

Your microwave experiment gave me an idea - a small, electrodeless fluorescent capsule mounted inside the oven to act as the oven light. It doubles as a diagnostic indicator for magnetron output.


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## PhotonWrangler (Jul 14, 2019)

So I looked at the RF output of this lamp on a SDR and found a strong carrier at 2.86mhz that slowly drifted to 2.85mhz as it warmed up. I can't think of any household devices that operate in that range so I don't see any local interference happening other than shortwave radio interference. Surprisingly I didn't see any harmonics in the output. I also found a patent from the manufacturer that describes these bulbs.


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