OK, for whatever reason, I've been on a #CRT kick lately.
Let's talk about the flood beam CRT - a defocused CRT with no deflection (and therefore no scanning), so the whole thing lights up.
As far as I'm aware, they've had three main applications.
Ferranti sold them as "vacuum light sources" with fast phosphors for stroboscopic applications as early as the 1950s: http://www.mif.pg.gda.pl/homepages/frank/sheets/074/c/CL60.pdf
Various manufacturers made them for large format displays, as seen below, source: http://www.industrialalchemy.org/articleview.php?item=1050
@kurisu As I said in the next reply... I think a lot of it is, you didn't really have to control the beam, you definitely didn't need all the deflection coils and scanning circuitry that most CRTs had.
And, all of the other technologies I can think of - really, until blue LEDs became viable - were impractical due to heat/power consumption issues or too slow cycling.
Why not use incandescent bulbs in large format displays? Heat generation and lifespan were huge concerns, and without deflection circuitry, you removed a lot of the cost of a CRT.
Which, speaking of replacing incandescent bulbs... the third application. There's a company that in this decade, is making flood beam CRTs (or "Electron Stimulated Luminescence light bulbs") for residential lighting: http://www.vu1corporation.com/products/index.html
No, this doesn't make sense. It's 1/3 to 1/4 as efficient as comparable LEDs.
For comparison, the comparable LEDs that I used:
* The Cree 65 watt BR30 replacement, at 8 watts, 605 lumens for 2700 K color temperature per http://creebulb.com/media/document/file/b/r/br30_sales_sheet_0716.pdf
* The Philips 65 watt BR30 replacement, at 8 watts, 800 lumens for 2700 K color temperature per https://www.usa.philips.com/c-p/046677473662/led-reflector/specifications
Note that they use less than half the power, and emit more light.
wait wtf
I'm watching a teardown, and apparently the thing actually has a yoke and a flyback and all: https://www.youtube.com/watch?v=pgiXcolLH9s
They actually bothered to scan the thing rather than defocus it? wtfffffffffffffffffff
https://www.lighting-gallery.net/gallery/displayimage.php?album=119&pos=42&pid=104441 claims it sounds just like a monitor. That implies 15.75(ish) kHz flyback frequency.
...why do I suddenly think that this thing is a way for some Chinese factory to use up stocks of 5" B&W CRT TV parts?
You know, I'm wondering if it has something to do with how they're dimmable - have the deflection circuitry widen the scanning as voltage drops, maybe, to keep the beam lighting the whole phosphor?
AFAIK most of the other applications of flood beam CRTs didn't care if the phosphor was only partially lit as intensity reduced, but in residential lighting, you do want the whole surface lit up.
@bhtooefr wondered how these worked but never looked it up. thanks!!
@bhtooefr I thought this was a rubix cube at first
This is the next phase of vaporwave
