Biggest engineering mistakes in audiophile gear

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There is pressure today for Tesla to recall 158,000 cars in USA as they use consumer grade flash in the infotainment unit. Unfortunately if that goes down you lose a few critical things like rear view and control over window demisting and other stuff.



You might have thought that they would have employed at least one person with history of speccing auto grade components and FMEA analysis.
 
Tefal, who make the Jamie Oliver pan are a French company...

Please friends, dump all your Teflon coated frying pans tomorrow. A parrot will die immediately from someone frying an egg meters away in a Tefal pan.

Talking about 'biggest engineering mistakes" Canaries in the Kitchen | EWG

Edit: a parrot is a clever bird, the look of an egg might trigger strong parental instincts in it, but I gather it will not die on the spot out of ethical despair in this scenario.
 
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There is pressure today for Tesla to recall 158,000 cars in USA as they use consumer grade flash in the infotainment unit. Unfortunately if that goes down you lose a few critical things like rear view and control over window demisting and other stuff.



You might have thought that they would have employed at least one person with history of speccing auto grade components and FMEA analysis.


Ahhh. Automotive PPAP’s. How well I remember it. FMEA’s galore. 3 lots of 78 with full 1000 temp cycles, HTRB etc. Zero failures allowed.

Tesla need their a-holes fried for that.
 
Please friends, dump all your Teflon coated frying pans tomorrow. A parrot will die immediately from someone frying an egg meters away in a Tefal pan.

Talking about 'biggest engineering mistakes" Canaries in the Kitchen | EWG

Edit: a parrot is a clever bird, the look of an egg might trigger strong parental instincts in it, but I gather it will not die on the spot out of ethical despair in this scenario.
I was prepared to argue wit you, since the temps listed were far too high.

Then they mentioned broiler.... oh yah, there's that.

I always use the fan..

Jn
 
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We accept the challenge.
Looking at topo maps, I believe that Amsterdam wins. It seems to have a variation of about 1 meter over a distance of 18 km. My city changes by 2.5 meters over the same distance. Still, it is hard to notice these hills. :)

Florida rises to 95 meters along the central ridge. I usually take supplemental oxygen when driving across that part - and a parka for the cold winds. Luckily down in this part of the state it doesn't get above 10m.
 
The time constant from the dissipative junction to the copper package back is in the roughly 1 to 100 milliseconds. From package case to heatsink is roughly a second. To the dissipative surfaces, 10 seconds or longer. That heatsink won't work well if high power transients last more than 5 or 10 seconds.

Aluminum isn't as good as copper w/r to heat capacity, so heat does travel faster (higher diffusivity). But copper as you mention, is much better.

I saw mention of fan reliability. As an antique clock repair instructor, I shy away from bearing solutions, as they never last as long as bushings. I use brass or bronze, and after broaching to ID, use smoothing broaches.

At work, we have thousands of fans, and over the years (roughly 10), we are replacing many units because the bearings are seizing up.

We are now replacing some with bushings, and find in the literature that bushings that are oilite and well designed are supposed to be the ultra reliable ones. Apparently even with oilite bushings, it is possible to mess them up if you do the machining steps either out of order or incorrectly. I suspect (and hope) that Mr. Hoyt will chip in with some of his (intimidating to me)

Jn
I have heard that you should not ream Oilite bushings... something to do with smearing the pores closed and blocking off oil flow.
 
When I had the time and saw the office in I would ride the bike at least one way from time to time.
It is a 24 mile trip with a 350 foot climb out of Boulder going towards Denver.
I think my house in Denver is about 90 feet higher than the office.

Aside from picking the safest streets and paths, I had to optimize for terrain.
Going straight north from home seems the easiest but is the most punishing.
I got tired of encountering a 150 foot quick drop with a likely red light at the bottom, had to re route.
Eventually they built a bike path that does not have traffic and is perfect for terrain.

Still cannot ride a 3 speed or fixed gear for sure.
 
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Looking at topo maps, I believe that Amsterdam wins. It seems to have a variation of about 1 meter over a distance of 18 km. My city changes by 2.5 meters over the same distance. Still, it is hard to notice these hills. :)

Florida rises to 95 meters along the central ridge. I usually take supplemental oxygen when driving across that part - and a parka for the cold winds. Luckily down in this part of the state it doesn't get above 10m.

Hello Pano,
If you cycle regularly , dont smoke and take care of your BMI all those bumps in your state wont be that much of a challenge.
Of course dont get tempted to get an electric bike. Here everyone is buying them. I only would consider one if i need to commute a big distance on daily basis.

Talking about quality how about le Creuset ( iron pans that adds a bit to your cooking skilss)and Peugeot ( pepper and coffeebean grinder).
I know people who moved their tube based table radio to their unheated garage 40 years ago. It KEEPS working and the stereo gear that replaced their Philips Bi-ampli has been replaced every 8 years on average.
My Philips also still fires up perfectly. Philips was long time considered quality brand!!
Philips B5X04A Engels
The Germans also had some nice brands that keep working. Loewe opta, Grundig, Telefunken,
I remember my friend had a British made Racal army receiver. Build to last.
Greetings, Eduard
 
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HTRB... by far the most difficult...

You clearly understand reliability..

Jn

I wasn’t on the engineering side, but the product dev team was embedded in the product line, so we were all at the rock face and sweated it out together (platform dev was handled by a central group - standard semi business model).

Nasty stuff - especially gate leakage current on power mosfets destined for ABS and ECU applications.

Worst situation was running all the tests and then right at the end after 3 months you get a failure.

Sometimes you could (I stress sometimes) produce an 8D report and the customer would pass it with a pending follow up test but that was very rare. Most times, back to square one.
 
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When I had the time and saw the office in I would ride the bike at least one way from time to time.
It is a 24 mile trip with a 350 foot climb out of Boulder going towards Denver.
I think my house in Denver is about 90 feet higher than the office.
Wow, that's quite a ride. How long did it take? And how many gears did you need? When I lived on Maui the office was 2.5 miles from home and about 80 feet higher, I would always walk or ride my bike. Coming home was fun, I didn't have to peddle at all for the first 1.5 miles. It was a gentle 1% grade.
Then I moved to Kona where the office was 1500 ft below the house. Going the back way it was a 4.5% grade, or straight down at a 9% grade. My ears would pop at least twice. No, I did not ride my bike. ;)
 
I got down to about 90 minutes when in shape and could hit 80 minutes with a little wind assist. At the height of biking to and from work there was a long term road project that made driving less fun. I found myself looking at the clock in the truck at times and realizing I just cleared an hour and I am not home yet. Wising I was on the bike instead. Road conditions for the car and bike route have improved.

I just have a 7 speed on the back and got rid of the front deraleur for weight loss. A brother ran a bike shop and helped me get a good pair of wheels for $450 and a Soma steel frame for cheap due to some painting/decal error.


I need to get on the bike again more this year and just hope we get to do a decent mountain biking trip this spring.
 
Worst situation was running all the tests and then right at the end after 3 months you get a failure.

Here is one, my father told me. There were too many trouble with too many failures at equipment panel lights.
So he asked the sourcing guys to test them.
Things got much worse. He yelled at them, the answer was, they did test the bulbs.
At last, he went to see them. He found they had a board to test ALL received light bulbs and those that had stand many hours of service were religiously put back in their box labeled Good.
 
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