71   General / Off-Topic / I'm tired...  on: February 21, 2026, 04:53:40 PM 
Started by Foxtronix - Last post by Foxtronix
If it was purely physical I wouldn't mind it much, but it goes so much further than that...

To put it simply, my life isn't going anywhere. I've only got physical health on the positive side, but for how long?

Mental health is in the dumps because my life has always been filled with conflicting emotions I can no longer avoid. The problem isn't so much their intensity, I actually appear quite stoic to people around me. But the choice between say solitude and (mild-ish) social anxiety is consuming me. I've probably been too emotional to have meaningful friendships my entire life, which also made me avoid college. But I must stop lying to myself and pretend I'm a-OK alone. The weight of solitude is real, has always been.

Now the whole situation is snowballing into despair and I feel powerless. Psychotherapy didn't help much and SSRIs scare me because of the potentially permanent side effects, plus they wouldn't solve the problem. I spent most of my life running away from anything (and anyone) unpleasant because I couldn't bear it. That won't work forever. And it's already made so much damage. I'm quickly reaching what is statistically the halfway point of life with a completely empty existence and nowhere to go. I understand that ultimately life isn't a race and most steps in life have a much wider window of opportunity than we like to think. I just can't help but wonder: at some point can things even be saved at all?

My philosophical journey brought me to Buddhism, which feels like a godsend now, otherwise I don't know what to do. I'm lost, and exhausted...
 72   General / General Discussion / Re: Transparent Alumina Arc Tubes  on: February 21, 2026, 03:34:14 PM 
Started by Multisubject - Last post by Multisubject
@RRK
Oh absolutely, all transparent arc tube technologies for CMH or HPS have been discontinued, and for good reason. I was just thinking that if they tried it with the much more expensive YAG ceramic, I would assume that they would try it with alumina as well.
 73   General / General Discussion / Re: Transparent Alumina Arc Tubes  on: February 21, 2026, 02:29:03 PM 
Started by Multisubject - Last post by RRK
I am for sure not competent in Al2O3 material science, but can speculate the reason is production costs, as always. Real efficiency benefits of having a transparent arctube are too small to bother.
 74   General / General Discussion / Transparent Alumina Arc Tubes  on: February 21, 2026, 12:14:12 PM 
Started by Multisubject - Last post by Multisubject
One method was devised for making transparent arc tubes out of aluminum oxide, and it was the process of growing a tubular single-crystal sapphire arc tube (Corstar) with the EFG process. Obviously Corstar did it's job semi-sufficiently, it was used for a little bit in HPS arc tubes. But I have a question:

Being a single crystal, the Corstar tube had a different CTE length-wise than width-wise (problematic for sealing). Well did they have any other choice? I think they may have, but I could be wrong.

On Lamptech, it is said that YAG (a ceramic material) can be sintered with a larger grain size to yield something similar in translucency to the typical PCA used for ceramic arc tubes, or could be sintered with very very small grain size to yield something with very high transparency (while presumably remaining more or less amorphous). I also know that YAG can be grown in a single-crystal format with the EFG process, but this appears to be done only for scientific or laser applications unrelated to lighting.

So to summarize, YAG can be made translucent with larger grain sintering (done regularly with alumina to make PCA), YAG can be made transparent with EFG (done before with alumina to make Corstar), but YAG can also be made transparent through smaller grain sintering (not done with alumina as far as I am aware).

What prevents them from sintering small (~1 micron) alumina particles to make an amorphous transparent alumina product with no weird CTE problems? Just like they did with YAG? This would have all of the benefits of PCA (uniform CTE) and all of the benefits of Corstar (transparency) combined into one product, while probably being a lot cheaper than YAG and more resistant to halide salts than YAG.

Here is the transparent sintered YAG lamp on lamptech that I speak of:
https://lamptech.co.uk/Spec%20Sheets/D%20MHC%20Toto%20YAG70.htm

Anyone know enough about material science to answer this question?

Thanks!
 75   General / General Discussion / Re: AJC - HAWK pedestrian signals confuse some drivers  on: February 21, 2026, 07:19:31 AM 
Started by rjluna2 - Last post by sol
A town nearby has a pedestrian traffic signal at a busy crosswalk on a busy street. It consists of standard red-yellow-green signals on the street and standard hand-walking-person signals on the crosswalk. The main difference between this one and other intersections is that it has signs prohibiting turning right on red and no automatic operation. By default, it always shows green on the street and the hand on the crosswalk. Pedestrians trigger the cycle manually with the button so it shows red only when needed. No confusion. This configuration is quite rare because of costs probably, but is perfectly understandable by drivers and pedestrians because it uses familiar components. It is located in Atlantic Canada.
 76   General / General Discussion / Re: Visual Flickering Caused By Switching Off a Magnetic-Ballast Fluorescent Light  on: February 21, 2026, 07:03:59 AM 
Started by rapidstart_12 - Last post by sol
I know what you’re talking about. I believe it might not be related to the magnetic ballast like you think. I’ve had it happen to me with incandescent light. I don’t turn on the bathroom light in the middle of the night anymore because I now have a proper night light in there, however.
 77   General / General Discussion / Visual Flickering Caused By Switching Off a Magnetic-Ballast Fluorescent Light  on: February 21, 2026, 06:27:16 AM 
Started by rapidstart_12 - Last post by rapidstart_12
OK, I may sound a little crazy for this one, but hear me out. Recently, I replaced the high-frequency electronic ballast in the fluorescent light fixture in my bathroom with a traditional line-frequency magnetic ballast. I am very satisfied with the results, however, I’ve noticed a weird effect that occurs to me when I turn the light off abruptly at night.

Occasionally, I have to get up and use the bathroom in the middle of the night, as I’m sure we all do. Usually, when I go in there, I turn on the fluorescent light so that I can see what I’m doing. I experience a bit of eye strain when I first turn on the light, but that’s nothing out of the ordinary. The strange part occurs when I turn the light back off, abruptly going from the magnetic-ballasted line-frequency fluorescent lighting to nearly complete darkness. In the past, with the electronic ballast, everything would look relatively normal to my eyes after enduring this transition. But ever since the magnetic ballast went in, I’ve been noticing that there’s some sort of a “flickering” effect that occurs in my eyes after the light is turned off. It lasts for several seconds but it usually goes away when I close my eyes. Visually, the color of the flicker is white, it sort of looks like increasing and decreasing the opacity of a photograph if that makes sense.

I am really curious as to why this occurs. I am pretty certain it has something to do with the magnetic ballast, since it has only been occurring since that went in. My theory is that my eyes are adjusting to the inherent flicker of that lighting, and then when the lighting is removed, my brain tries to fill in the gaps by producing “flicker” of its own. I don’t think there is any bodily damage caused by this effect, it’s just a strange sensation. Has anyone else experienced a similar thing before? Is it true that the magnetic-ballast fluorescent lighting is the source of it?
 78   General / Off-Topic / Re: Neon-Filled CRT with Visible Electron Beam!  on: February 21, 2026, 03:41:17 AM 
Started by Multisubject - Last post by LightsAreBright27
@lightsofpahrump raster would be cool, but it doesn't work well on slow scan CRTs. If you want to make the scanning rate faster, the neon beam would be moving too quick so it will become too faint to see
 79   General / Off-Topic / Re: Neon-Filled CRT with Visible Electron Beam!  on: February 20, 2026, 10:51:02 PM 
Started by Multisubject - Last post by lightsofpahrump
I would like to see that displaying not only vector, but raster graphics. The glow filling the tube would look cool.
 80   General / General Discussion / Re: EOL Protection Questions  on: February 20, 2026, 03:42:51 PM 
Started by Emersyn - Last post by RRK
This depends on which ballast/lamp system we are talking about.

It is problematic to implement a comprehensive EOL protect circuit in a magnetic ballast. Usually a bimetallic switch (if any at all) is placed inside the coil to limit maximum temperature. Thermal time constant for its trip may be in some minutes to tens of minutes.

Starters used with fluorescents on magnetic ballasts may have a thermal bimetallic cut-off built-in.
Electronic starters for fluorescents employ some ignition timeout too, and usually an one-time thermal fuse.
Electronic ignitors for HIDs on magnetics sometimes add a time out circuit for the case when there is no lamp or the lamp fails to ignite.

Electronic ballasts for fluorescents typically use a circuit which monitors high resonant voltage for the time lamps string is gong to ignite. Any longer than a fraction of a second, circuit goes to shutdown. Too high voltage over the tubes in the running phase also triggers a shutdown. Thus a stress on the ballast components is limited, and also cracking of the tube with EOL electrodes that have spent all of the activation may be prevented. Many electronic ballast for fluorescents also have a circuit to monitor filament continuity. But adding such a circuit is complicated, and only a limited number of filaments, not all of them, is monitored. So, this circuit works more for 'lamp present check' and 'lamp change reset' functionality.

Electronic ballasts for HIDs today most universally employ a microcontroller, so may be made quite clever. It is programmed to catch abnormal lamp behavior like voltage too high, power too high, voltage too low and failure to run up, failure to ignite and so on. Some implementations are even attempting to detect a dreaded dangerous EOL behavior with arcing in the outer bulb or over the base.
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