As the electrons are swept across the broken down junction by 1400 V they can pick up enough energy to damage the lattice since the junction was not designed to operate that way (and, in all likelihood, it's ability to behave well under those conditions was sacrificed in order to get better performance under the conditions that it WAS designed to operate under. I would not be surprised that the sacrifices made to achieve the tradeoff are more severe for diodes that are designed to carry higher and higher forward currents.

Interesting! -- Your observations are certainly consistent with my experience (assuming the 'altered' diodes' reverse leakage indeed owes to 'junction insufficiency' -- as opposed to external 'electrolytic conduction') -- Though I must confess to no small surprise! - Apparently junction fabrication in rectifier diodes varies significantly from that in BJTs? -- I have, for instance, seen several (mass produced) designs wherein the B-E junctions of Si BJTs are biased for Zener operation

Many thanks and very best regards
HP

 

HP admit it! You'd be lonely without your ghosts!

Perhaps I should furnish the guest wing with Casper mattresses?

TTFN
HP

 

Re, Post #20:
I suspect the dye is applied after firing. Its purpose is to seep into very small cracks, which can then be revealed by UV or other methods (see below). After application of the bulk dye, it is wiped off, which leaves only that dye retained in cracks.

With metals (including cast or forged pieces), we wiped with a solvent after the initial spray. Then, a fine powder like chalk or talc ("developer") was sprayed on the component. The dye wicks back out of any cracks to give a color trace on the chalk/talc. One could use UV directly or after application of the "developer," but as it was for aircraft, we had to follow the directions. With some approved kits, UV was not required.

The color you see is just what adsorbed to the surface. If you have a Wood's lamp, take a look.

John

 

The color you see is just what adsorbed to the surface. If you have a Wood's lamp, take a look.

Thanks! I've just performed the suggested experiment!

Interestingly, irradiation by UVA (via a standard 'florescent black-light' [BLB phosphor, Min λ≈320 nm]) produces no florescence of the ceramic whatever Said observation, taken with the high 'gloss' and degree of uniformity seems to suggest the superficial material may be a glaze after all???

Many thanks for your continued interest!
HP

 

What part of confirmed hermit do you find incomprehensible/worthy of contemplation?

Just having more fun here. So the fly may only hear a muted bzzzzz?

 

Just having more fun here. So the fly may only hear a muted bzzzzz?

Should I neglect to cover that mirror the fly might require counseling!

TTFN
HP

 

Just having more fun here. So the fly may only hear a muted bzzzzz?

I think there was a Saturday Night Live skit about that in the days of John Belushi - "The Killer Bees".

 

Should I neglect to cover that mirror the fly might require counseling!

TTFN
HP

If you're truly a hermit (and I have no reason to believe the contrary) I can only imagine that, with time, the poor fly would end up talking to itself...

 

Should I neglect to cover that mirror the fly might require counseling!

...unless, that is, our hypothetical fly was of the fabled 'Amityville stock' -- in which case I expect 'la habitants du miroir' would make it feel 'right at home'!

TTFN
HP

 

...unless, that is, our hypothetical fly was of the fabled 'Amityville stock' -- in which case I expect 'la habitants du miroir' would make it feel 'right at home'!

TTFN
HP

Ughhh... you mean the big, fat green fly that usually appears when something organic decomposes?
Please don't put that image in my head !

 

Ughhh... you mean the big, fat green fly that usually appears when something organic decomposes?
Please don't put that image in my head !

What image did that green fly replace, @cmartinez ?

 

What image did that green fly replace, @cmartinez ?

ever watched CSI? I try to avoid that show when I'm having lunch!

 

Ughhh... you mean the big, fat green fly that usually appears when something organic decomposes?
Please don't put that image in my head !

'Bitten' by the green bottle fly, aye!

ever watched CSI? I try to avoid that show when I'm having lunch!

Paint me old fashioned - howbeit I find 'Quincy ME' more 'cerebral' (even if less accurate) -- Cuz ya see, for some unaccountable reason, I find that I have no interest whatever in the 'love lives' of public servants, etc...

TTFN
HP

 

'Bitten' by the green bottle fly, aye!

Paint me old fashioned - howbeit I find 'Quincy ME' more 'cerebral' (even if less accurate) -- Cuz ya see, for some unaccountable reason, I find that I have no interest whatever in the 'love lives' of public servants, etc...

TTFN
HP

I always thought Quincy ME was also too unbelievable to watch - an occupation that requires meticulous care and organization - then thinking of how many innocent people were going to jail (or guilty people getting set free) based on examinations completed by Oscar Madison.

 

I always thought Quincy ME was also too unbelievable to watch - an occupation that requires meticulous care and organization - then thinking of how many innocent people were going to jail (or guilty people getting set free) based on examinations completed by Oscar Madison.

Indeed! Jack Klugman was curiously cast in that role --- But the 'lightning-esk' celerity with which pathology reports -and especially- toxicology results 'came back' was pure magic to behold!

With nostalgic regards
HP

 

an occupation that requires meticulous care and organization

Put that way, one wonder's if Tony Randall might have been a better (casting) choice? But then I expect forensic pathology likely 'falls beneath' his 'aesthetic standards'

TTFN
HP

 

Just a footnote: The College of American Pathologists in Northfield, IL (https://en.wikipedia.org/wiki/College_of_American_Pathologists) frequently got calls for Dr. Quincy. Some of the staff joked about making a parking space for him.

What is scary is that the American TV audience can't tell fiction from reality. Unfortunately, that ignorance continues to be proved today.

John

 

Put that way, one wonder's if Tony Randall might have been a better (casting) choice? But then I expect forensic pathology likely 'falls beneath' his 'aesthetic standards'

TTFN
HP

My wife just told me a re-launch of the Odd Couple is currently airing with Matthew Perry (from Friends) in the Oscar Madison role. How odd, I would have pictured him as a Felix.

 

that ignorance continues to be proved today.

yeah, in the form of "reality" shows...

 

yeah, in the form of "reality" shows...

The really sad thing about that is that it is no secret. So-called reality show stars have a job!

John