Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

One big advantage of laminated glass over toughened is you can still see the road after a stone strike. Certainly in the UK there was probably more hazard due to that than hitting the screen post the seat belt law.
This is what drove the laminated requirement in the UK at least. In the Construction and use regulations there was a change in the mid 1980's from requiring "safety glass" to "specified safety glass" (reference my printed copy of the construction and use regulations of the era). Apart from laminated, there was an option for a selectively toughened glass where the section directly in front of the driver "primary vision area" was not toughened and remained clear if the rest shattered (BS 857). This glass was not common (I've seen one windscreen like this in broken condition). Most companies switched to laminated bonded windscreens because of the saving in weght and increased body stiffness.
Having had a toughened screen break (on a classic car with no warning and no stone thrown up as no other car around) it's pretty scary. I was on a twisty narrow road at night and I was doing the speed limit. I ended up pretty much across the road at a bend. Fortunatly nothing was coming the other way.

Just out of interest and because I happen to be in an e-mail back and forth with the engineer responsible for the glass in my current product (because the rain/light sensor isn't working as it should), I asked him whether the windscreen is tempered / toughened etc in our vehicle. His "you philistine's!" answer was: We are all simplifying the glass down to a single object with a single process, it is far from that simple. Modern glass will have different heat treatments for different areas of the glass, depending on the surface area, curve, total size of the screen, angle of the screen, glass thickness etc. It could have multiple areas with different processes and different levels of tempering / toughening. It's not completely tempered, but it's also not untempered.

By the way, although the UK like to have their own BS standards, no car manufacturer that I know of actually uses them. As most OEMs want to sell their cars in many countries, the ECE Regulations (No. 43 in this case) are what are normally used (even in traditional UK companies).

McBryce.

The UK uses the harmonised EU standards, which IIRC, all carmakers use some form of compatible standards otherwise their export markets are severely curtailed. The last time we in the UK used pure BS standards was before we joined up with the EU in the first place, otherwise we could not join the club unless standards were the same for obvious reasons.

[bd139]

Oh, why, oh why the flying fuck is the input-ground-output pin sequence on LM7815 and LM7915 not the same?

Because that would be too simple... 

It made the internal IC layout simpler so yes 

[med6753]

Oh, why, oh why the flying fuck is the input-ground-output pin sequence on LM7815 and LM7915 not the same?

Because that would be too simple... 

It made the internal IC layout simpler so yes 

I almost fell for that when redesigning the +/- 15V Fluke 8000A PSU to utilize the 7915 and 7815. I guess for once the ass-u-me kicked in. 

[Cerebus]

By the way, although the UK like to have their own BS standards, no car manufacturer that I know of actually uses them. As most OEMs want to sell their cars in many countries, the ECE Regulations (No. 43 in this case) are what are normally used (even in traditional UK companies).

For your information the British The Road Vehicles (Construction and Use) Regulations 1986 (as amended) actually calls out both BS AU 178 and ECE regulation 43:

“specified safety glass (1980)” means glass complying with the requirements of either—

(i )the British Standard Specification for Safety Glass for Land Transport published on 30th June 1967 under the number BS 857 as amended by Amendment Slip No. 1 published on 15th January 1973 under the number AMD 1088, Amendment Slip No. 2 published on 30th September 1980 under the number AMD 3402, and Amendment Slip No. 4 published on 15th February 1981 under the number AMD 3548 (including the requirements as to marking); or

(ii) British Standard Specification BS AU 178 (including the requirements as to marking); or

(iii) ECE Regulation 43 (including the requirements as to marking).

And if you go to the BS site:

BS AU 178a:1980 is now replaced by the 1992 version which has been produced to align the standard with ECE (United Nations Economic Commission for Europe) Regulation 43.

So, as is often the case with national standards, it's essentially the same as some broader regional or international standard. In those circumstances I often find that the text is that of the regional/international standard just wrapped in the front/back pages and formatting style of the national standards body. Whether that's true for this particular BS I don't know as there's not a copy floating about on the web.

[Specmaster]

One big advantage of laminated glass over toughened is you can still see the road after a stone strike. Certainly in the UK there was probably more hazard due to that than hitting the screen post the seat belt law.
This is what drove the laminated requirement in the UK at least. In the Construction and use regulations there was a change in the mid 1980's from requiring "safety glass" to "specified safety glass" (reference my printed copy of the construction and use regulations of the era). Apart from laminated, there was an option for a selectively toughened glass where the section directly in front of the driver "primary vision area" was not toughened and remained clear if the rest shattered (BS 857). This glass was not common (I've seen one windscreen like this in broken condition). Most companies switched to laminated bonded windscreens because of the saving in weght and increased body stiffness.
Having had a toughened screen break (on a classic car with no warning and no stone thrown up as no other car around) it's pretty scary. I was on a twisty narrow road at night and I was doing the speed limit. I ended up pretty much across the road at a bend. Fortunatly nothing was coming the other way.

Yep, the date was April 1st 1985, cars used before that date could use safety glass, after that date had to be specified safety glass (1980)

[Specmaster]

By the way, although the UK like to have their own BS standards, no car manufacturer that I know of actually uses them. As most OEMs want to sell their cars in many countries, the ECE Regulations (No. 43 in this case) are what are normally used (even in traditional UK companies).

For your information the British The Road Vehicles (Construction and Use) Regulations 1986 (as amended) actually calls out both BS AU 178 and ECE regulation 43:

“specified safety glass (1980)” means glass complying with the requirements of either—

(i )the British Standard Specification for Safety Glass for Land Transport published on 30th June 1967 under the number BS 857 as amended by Amendment Slip No. 1 published on 15th January 1973 under the number AMD 1088, Amendment Slip No. 2 published on 30th September 1980 under the number AMD 3402, and Amendment Slip No. 4 published on 15th February 1981 under the number AMD 3548 (including the requirements as to marking); or

(ii) British Standard Specification BS AU 178 (including the requirements as to marking); or

(iii) ECE Regulation 43 (including the requirements as to marking).

And if you go to the BS site:

BS AU 178a:1980 is now replaced by the 1992 version which has been produced to align the standard with ECE (United Nations Economic Commission for Europe) Regulation 43.

So, as is often the case with national standards, it's essentially the same as some broader regional or international standard. In those circumstances I often find that the text is that of the regional/international standard just wrapped in the front/back pages and formatting style of the national standards body. Whether that's true for this particular BS I don't know as there's not a copy floating about on the web.

I looked earlier for one and I was directed to the BS site where they are I believe asking £95 for a copy 

[Specmaster]

Oh bugger, I got so wrapped in this thread about safety glass that I forgot to put my bid on a nice Fluke 85 and it went for just £25.70 delivered 

[McBryce]

Oh bugger, I got so wrapped in this thread about safety glass that I forgot to put my bid on a nice Fluke 85 and it went for just £25.70 delivered 

Sorry! That would have been a seriously good deal.

McBryce.

[med6753]

All I know about windshields is that the Civic is currently on it's third windshield due to careless dump trucks tossing stones on the highway. The CR-V had a star crack repaired with the clear epoxy 2 years ago.

As long as you have (and pay extra for) "Full Glass Coverage" on your auto insurance policy the cost is zero. The glass outfits will even come to your house and change out the windshield. Takes about 15 minutes and it's amazing to watch them.     

[Cerebus]

Oh bugger, I got so wrapped in this thread about safety glass that I forgot to put my bid on a nice Fluke 85 and it went for just £25.70 delivered 

[med6753]

Oh bugger, I got so wrapped in this thread about safety glass that I forgot to put my bid on a nice Fluke 85 and it went for just £25.70 delivered 

Have you no sympathy? 

[BU508A]

Oh bugger, I got so wrapped in this thread about safety glass that I forgot to put my bid on a nice Fluke 85 and it went for just £25.70 delivered 

Have you no sympathy friends? 

Fixed that for you. 

[mnementh]

It's the same problem as the Chinese have and should be in the US; the exponential growth of a parasitic drain on the world's electrical grid. Conservative estimates say cryptomining will be consuming 10% of the world's electricity in the next year or three.

That said... am I the only one here who sees that video as a very obvious fake...? Seriously...?

mnem

Does that mean we're going to restrict endless server farms for high frequency trading or perhaps the gold mining industry too? I'm not sure what's "obviously" fake about the video. The Philippines are known to destroy equipment they deem illegal and what look like typical ASICs are run over in the video. It could be a very high detail CGI render by Egyptian aliens but I couldn't tell.

Very high detail...? Are we both looking at the same video?   https://youtu.be/c_tcg9kOfkg   The render is fucking horrible; worse than XBOX, and I'm talking the original, not what they call a XBOX now.      I'm pretty sure bd could hand-draw better on his iPud. 

mnem
 

[mnementh]

hooray for diverse TECHNICAL discussion!!!

Fixed it for you. 

meh. 

mnem
raising yer blood pressure every once in a while is good for ya.

[med6753]

With respect to the Heath V-5 VTVM this kit is proving to be somewhat of a challenge to build. I really doubt a beginner would get it right the first time. Many of the Heath tips and detailed instructions seen on later kits aren't present. Some examples. No wire lengths are given. You are left to your own devices to figure it out. No mention of proper lead dress either. But the biggest issue is the designation locations for various parts. There is one small diagram showing the locators. But these locators are NOT shown on the large fold out pictorials. So you have to flip back and forth in the manual to cross check. For example it will say "install wire on Z-3 (S)". Well "Z" turns out to be the AC Balance Pot. But unless you flip back to that small diagram you have no idea what that means.

Another thing is when it says "NS" for no solder in later kits when you come back to that point it will say something like "S2" to indicate that there was a prior wire installed at that point. Not this kit. It simply says "S". Obviously Heath learned over the years to add these small helpful details probably because they were overwhelmed with non-functional kits. 

[mnementh]

PHE have suggested that Pfizer is 96% effective and AZ is 92% effective against hospitalisation so far against Delta. That's pretty good.

We appear to be the only country which has any decent data on anything at the moment which is also pretty good.

We have very little into on long covid, of course. That may well be more significant than the death rate, over the coming decades.

Yes that is my main concern. I've lost one team member to it already.

Tomorrow, in the UK, is being called "Freedom Day", where legal restrictions on what we can w.r.t. covid are being removed. We will be living in a petri dish, watched by the entire world.

Most sheeple think "freedom" refers to their freedom. A more useful realization is that the government has given themselves the freedom to absolve themselves of the consequences, and shift the blame onto the "feckless people".

And in America, it's the wealthy few who enjoy the fuck outta that particular privilege... which disease is spreading virally worldwide, and will destroy us all far more surely than COVID.

mnem
But hey... it will make for some interesting mineral deposits when men are ought but bedtime stories told by rabbits... 

[Specmaster]

Oh bugger, I got so wrapped in this thread about safety glass that I forgot to put my bid on a nice Fluke 85 and it went for just £25.70 delivered 

Sorry! That would have been a seriously good deal.

McBryce.

Thats OK, it was sold as spares/repair as they didn't know how to test it anyway, although it was switched on in the mV range and with no leads plugged was reading 0.7mV which is about the right value for free air anyway. Besides did I really need another meter, not really but this is TEA after all 

[med6753]

To our German friends. Are any of you affected by that flooding? I saw some of the videos and holy shit what a mess. 

[mnementh]

Neither have I. Protecting Gorilla-glass with more Gorilla-glass always seemed like a pretty futile exercise to me.

McBryce.

Actually if stuck together with a non rigid adhesive it adds a lot of extra strength. That is why windshields and bulletproof glass are laminated.

Kind of. Car windscreens are mainly laminated to keep the glass together after it has shattered instead of having a wall of shards flying towards you if something breaks the windscreen.

McBryce.

It's both. They're stronger and large shards are kept captive. If it were just the shard protection, they'd be made of tempered glass that shatters into tiny grit like the side windows.

In many modern cars, the windshield(s) is/are actually part of the stiffness of the monocoque; it provides part of the roof crush support that used to be entirely provided by traditional A/B/C pillar design.

There was a lawsuit a decade or so back in which a replacement windshield popped out of a vehicle during an accident due to improper installation, and the roof of the vehicle collapsed breaking the driver's neck, when according to the manufacturer, it should have maintained integrity. Lots of investigation, enginerding, etc... but ultimately it was found that the windshield was cemented in place improperly, making the glass company liable.

mnem
 

Front windscreens are made of tempered glass and shatter in cubes just like the side glass, and although they do offer some physical strength / stiffness to the vehicle during a rollover, this factor is ignored in the mathematics because the pillars need to be able to support the weight of the vehicle even when all windows have failed. So it's a bonus, but not essential.

McBryce.

Car windscreens have not been made from toughened / tempered glass for many years. They are made from laminated glass with very few exceptions (it is mandated for car windscreens in most countries).The added strength when bonded in is imprtant to many car designs.
 EDIT, Cerebus beat me to it.

Cars still use tempered glass, as this is what makes the glass break in cubes rather than long sharp shards. Lamination is usually only on the front windscreen but some manufacturers have started using it on side windows too which can be a problem. The windscreen of course adds strength to the design, I wasn't saying it didn't. I was just pointing out that the pillars still have to be designed strong enough to support the vehicle if the glass is missing / broken. The stiffness, especially in X/Y plane torsion is the main structural component of the windscreen.

I think that you are talking about the older type of cars that used a rubber surround to hold the windscreen in place. Modern cars are laminated and are held in place by a special type of adhesive and designed to prevent passengers from going through the glass and being ejected into the path of the vehicle in the event of an accident. Hence, why you can often see vehicles which have massive cracks in their windscreens, and the screen has not shattered into the cubes you mention like the door windows do. The side windows are so designed as they may be used as an emergency escape hatch in the event of the doors jamming each other shut after an accident, and you can buy special glass hammers to keep in the car for such an incident and hitting the side glass with the pointed part of the hammer will cause the glass to shatter and present a means of escape from the vehicle.

No, I mean current windscreens with bonding. Yes, they crack, but they don't shatter. The type of "chip" you get in a front windscreen could never happen with a standard pain of glass, even laminated glass, so the glass definitively has some level of tempering.

McBryce.

P.s. I am in discussions later this week with a Saint Cobain Engineer. I'll ask him exactly what process they are using on windscreens today.

P.p.s. Maybe I'm not explaining this properly, let's try with pictures. This is how standard glass breaks: Long sharp shards along the stress lines. And the other picture is how a windscreen breaks: Stress evenly spread across the entire surface. Not quite the "sugar effect" you get from breaking a side window, but far from standard glass too.

"toughened glass" and "tempered glass" have different names for a reason; they are different processes with different goals, as Cerebus has explained in great detail. Windshield glass is toughened to make it less brittle, which is why it does in fact shatter, but the laminate ensures that shattering is restricted to captive pieces. You still have shards, they're just a gazillion tiny slivers, which carries its own myriad safety risks, just not that of decapitation or shards large enough to slice open a vein as you would have with plate glass. This is a completely different kind of glass from tempered glass, which is given that name because of the very important role it plays in modern machinery of all kinds both from an engineering standpoint and from a legal standpoint.

On this point you are simply wrong. This has not been true literally for decades. Both from an engineering standpoint and from a legal standpoint a court of law in personal injury cases, this has been established and the windshield is, in most cases, considered an integral and essential part of the rigidity of the A-pillar structure, particularly for the purposes of rollover support of the vehicle roof.

EDIT: Both processes use heat-treating of the glass; that is not what I'm arguing here. "Heat-treating" and "tempering" are not the same thing here, just as they are not the same thing with metal.

mnem
 

[BU508A]

To our German friends. Are any of you affected by that flooding? I saw some of the videos and holy shit what a mess. 

Not so far, fortunately. But I am watching the weather maps closely.

[Specmaster]

To think that this discussion re the laminated v tempered glass all sprung forth out of a chat about Gorilla glass phone screen protectors, we must have covered just about every topic in this forum now apart from sex, who wants to start that one off then 

[mnementh]

mnem

[Specmaster]

To our German friends. Are any of you affected by that flooding? I saw some of the videos and holy shit what a mess. 

Not so far, fortunately. But I am watching the weather maps closely.

Let me ask you a question, but it is still really related to the topic. Do you have any organization whose job it is to maintain the rivers and streams over there? I ask because years ago we used to have a national network of county river authorities whose sole job was to keep rivers and ditches dredged, free from weed build up, and they used the dredged silt to build up the river banks. This served two purposes ensured the rivers were kept fast flowing, and higher banks meant they also had a greater flood capacity. Sometime around the late 1960's or 1970's these were disbanded and since then we have many bad floods which also means that now many people living in these areas are now, in many cases, trapped as they are both unable to sell their homes and cannot get any insurance cover.

So I was just wondering if that could be a contributory factor in the severity of the floods we have seen on the news?   

[mnementh]

Oh, why, oh why the flying fuck is the input-ground-output pin sequence on LM7815 and LM7915 not the same?

Because that would be too simple... 

It made the internal IC layout simpler so yes 

I almost fell for that when redesigning the +/- 15V Fluke 8000A PSU to utilize the 7915 and 7815. I guess for once the ass-u-me kicked in. 

It's because they are mostly the same silicon inside; only the reference is changed. You can actually use a 78xx in place of a 79xx and vice/versa by altering the reference/ground in the circuit.

mnem
 

[Cerebus]

OK, a +10 score on two fronts:


Click to embiggen.

Firstly, doing that above wearing the new 7 diopter Optivisor was a doddle. It was comfortable to wear and use (especially considering the room I was working in is currently at 30ºC). I got the whole job done in half the time or less than it would have taken me messing around with glasses, no glasses, loupe etc. I declare the Optivisor a win as far as I'm concerned.

Secondly, that was done with the mylar stencil shown that was cut on my little Silhouette Portrait arty-farty vinyl cutter. I've used it at 1.27mm, 0805 and 0603 before, this is the first outing that technique has had with a 0.5mm pitch part. Also winner winner chicken dinner.