I'm sure that what you said is quite correct for large companies, who place huge orders and can take their business elsewhere, but I was referring to products developed by other engineers I've talked to, where the orders are far smaller.
ar: Well I suspect that much of your argument is plausible, but I find it hard to believe that mega-billion $ SONY, PANASONIC, CANON, FORD, GM, VOLKSWAGEN, etal. would tolerate their products being re-engineered by some Chinese engineers. I'm sure that MOST of the products that are exported from China by non-Chinese companies are designed in their laboratories & engineering facilities around the "free" world. China has evolved into a manufacturing magnet because of the overabundance of inexpensive labor, lax environmental statutes, etc. The PLUS for China is that they get a massive infusion of world-wide cash to upgrade their entire infrastructure from military to mundane, AND they get immediate, unfettered access to a lot of technology quickly.
As far as repair is concened, I don't think ANY manufacturers, be they domestic OR foreign, want their products repaired! They want to sell, sell, sell!..... and the ONLY way to do that is to make the item irrepairable in the first place. Even though so many companies have joined the "environmentally righteous" bandwagon, they ignore the obvious...... filling our landfills with their junk!!!!! That's the dirty little "secret" of modern manufacturing. I am of an age where we recycled almost everything from old shirts used as polishing rags to soda & beer bottles, to just about every other item that one could think of which wasn't consumed somehow in the process of being used! We even burned the leaves at the curb in the Fall to eliminate the waist! That's BEFORE someone invented plastic bags for yard waste that the rubbish people pick up, OR the environmentalists decided that a bit of leaf smoke in the air was harmful for the ozone layer.......
Designing around parts availability makes perfect sense to me, but Chinese manufacturers nowadays do not want their appliances or gadgets repaired. They want to sell you new ones. I have talked to other engineers online and found out that Chinese manufactures will not manufacture products for you if they contain non-Chinese parts. If they manufacture them, they will redesign them to contain all Chinese-made parts. The Chinese do everything they can to force you to buy from them.
I don't know if my microwave was designed in China or Japan. Even a reputable company like Panasonic can make a mistake once in a while.
Since I'm a retired electrical engineer, now that I fixed the display, I could design and build a timer to keep the fan running for a minute or two after the cooking is complete. Then I'd have a perfect microwave. I have always liked Panasonic products when they were made in Japan.
The entire microwave (inverter, fan, light and turntable) is controlled by one SPST relay on the timer board. That will complicate building a fan timer a bit.
But, "Cheers" above claims they don't use the TORX screws for "security" reasons. So, my question then becomes, "why use the security version of the TORX screw instead of the garden variety of the TORX screw, IF NOT for "security" and limited access.
As far as minimizing the inventorying of all sorts of "extra" hardware items, I can speak first hand to that. Many decades ago, when printed circuit boards were becoming more prevalent, and point-to-point wiring was waning, the chief engineer issued a mandate that the minimum wattage for resistors shall remain at the 1/2watt ALLEN BRADLEY composition styles, with higher wattage styles used where deemed appropriate. Even though most of the circuits in our products were low level, and the entire product line COULD HAVE BENEFITTED from smaller p.c. boards by using 1/4w resistors, his reasoning was simple..... we shipped our products all over the free world, and THE MOST COMMON wattage carbon composition resistor was the 1/2watt variety! Every technical repair facility, whether in Houston, TX, or in S. Africa would have a broad assortment of 1/2w carbon comp. resistors on hand!
BTW, the Torx screws in my microwave are the "security" Torx screws with the center pin in them to prevent a normal Torx screwdriver from working. Still, the security Torx screwdriver bits are commonly available online and at your nearest Harbor Freight store.
We do not use TORX screws as some security feature or fear of litigation. We use them for two reasons: the production line folks can use electric (or air) drivers without stripping and TORX are the only screws that you can get consistant torque.
Every screw inserted into one of our products has a specified torque and all of the drivers are calibrated. Using a driver on Slotted, Philips and POZI screws takes more skill and has way more incidences of damaged screw heads or improperly torqued screws and greatly reduces product robustness.
Another aspect in a large corporation is materials management. If every assembly product has unique screw types and sizes the manufacturing and repair sites would have an infinite variety. It sometimes seems like a no-brainer to add a ten cent screw but when you add in the 10-20 minutes it took some repair tech to search stores for the right screw, at a 2-5 times overhead rate, your warranty cost is, or some customer pays, $60.
Your 20 minutes figure may be good for a single user, but is totally worthless when all my kids were still home or even worse when it is the microwave in the breakroom at work.
I think the idea of lawsuits is much more realistic. Or more likely still, is a company, Panasonic, riding on their reputation and knowing many people will buy brand only, so they can be slipshod and let occasional garbage through.
I also have a Panasonic Inverter microwave that is perhaps +8 years old and I like it. Have never had a problem with it. The LEDs issue described does sound like a monkey problem. But the fan doesn't:
The good microwave ovens blow air into the oven. It helps keep the humidity, created by heating/cooking items, from forming too much condensation inside the oven. The condensation can really make a mess of things, just look at the small cheap microwaves. To save money and power, one fan is used to cool the magnetron and blow air into the oven. The problem is that the fan stops when the oven stops. This leaves any condensation still in the oven,... in the oven. Perhaps the fan should run for another minute or two. So I also leave the oven door ajar after using it, to allow the interior to dry out. I also do this for the microwave at work which is not a Panasonic Inverter.
The inverter makes the microwave oven really nice. Rather than duty cycling on/off full power, the inverter continously controls the current through the magnetron(essentially, a diode vacuum tube). Changing the current changes the energy of the microwaves produced not the frequency. I have learned to tweak the microwave instructions on products. If it says high for 3-4 minuets, then I cook it at a lower power for a little bit longer.
After having this inverter oven, will always get an inverter microwave oven until something else better comes along.
AND, it's precisely because of the "bottom feeders" that you'll NEVER read a response from any current technology person in ANY corporation, either excusing or rationalizing a deficient design. I'm sure that there's literally tons of designers reading these same pages as we are, who are currently employed by these suppliers, and IF they COULD, they WOULD, but they appreciate that paycheck far more than the satisfaction of "ratting out" a dumb design.
Fauxscot, I did not mean to imply in ANY way that you were flinging.
My goal of the statement was that IF DN could convince a company to willingly sit in the hot seat to explain design intent with civil questions, we should be civil with our questions. Otherwise we ourselves will look like monkeys in the zoo (...flinging).
There was NOTHING wrong with your post and I apologize for even coming close to inferring that.
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For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.