I found that diodes in parallel are surprisingly common around the industry.
This is such a thing which you are pretty much told on day 1 of any electronics course that it is impossible to not to know.
My only thinkable conclusion was that people keep doing it on purpose.
Other extreme cost cutting measures I saw were things like LEDs being used in double role as a diode. Wire wound around PCB used as inductor. Plug pegs being directly soldered to the PCB. Near paper thin plastic with holes from molding defects. Through hole components being soldered to each other. Flybacks without feedback. A 555 coaxed into use in a charger circuit.
You cannot come with any of that unknowingly, nor will you find any of that crap on the open market easily even in China.
It's pretty much an engineering equivalent of a "controlled flight into terrain," a direct result of suppliers being consciously directed into "stripping to the last cent" of the products by such unwitting buyers.
I wouldn't be surprised if reference circuits would have the double diode. Sad, but not surprised.
You've got these manufactures that are struggling to make basic AC->DC inverters and now you want to throw on a negotiation step? Yeah, not going to end well for these cost cutting idiots.
There are going to be destroyed devices and fires because some idiot decides "Just hard wire 20v and be done with it!"
http://www.righto.com/2012/05/apple-iphone-charger-teardown-...
http://www.righto.com/2016/03/counterfeit-macbook-charger-te...
But then how did you assess the quality of Apple's chargers? Can the same methodology not be applied then to other brands as well?
How do you judge the quality and safety of charger purely by size? Is bigger safer, or is smaller safer? And if so, why don't other brands of the same size meet your quality standard based on that yardstick.
>and demonstrated product quality in other areas
Like their multi-year run of defective butterfly keyboards or hinge design that would cut through the MacBooks display cable over time causing the famous "stagelight effect" AKA "flexgate" where you'd being charged $600 to fix the $6 ribbon cable[1]?
[1]https://www.extremetech.com/computing/284236-some-apple-lapt...
Edit: Ah, I see the downvotes are already here. I guess criticism of Apple with proof is not tolerated on HN.
I'm pretty sure spoonjim was referring to the size of Apple, not the size of the chargers they make.
And how does one battery incident from one brand prove that Apple is the best at making chargers? We're talking about different things here.
"iPhones don't explode so Apple must be the best?"
Samsung Note 7 exploded before it was taken of the market, but any other brand or model did not, so unless you want to hang on the 2016 Samsung Note 7 incident as strawman argument, you have provided no valid arguments.
Who is more likely to commit murder, a randomly selected person or a randomly selected person from those with an existing murder conviction?
How does one negative battery incident from Samsung prove that Apple makes the safest chargers of ALL the major electronics manufacturers?
Because so far you provided no proof or arguments to support this other than "murderer" metaphors and opinionated brand loyalty wrapped in whataboutism focused towards one particular incident, then move the goalpost from safety to quality instead and I showed you proof that quality does not equal safety or vice versa.
Apple phones had antenna problems. You probably should not buy that brand anymore.
If you keep moving the 'logic' goalposts to justify 'Apple is the best', then let me point out to you that bad reception IS just as bad, if not worse than batteries that could potentially explode.
If you've got an accident or an emergency in a more remote area and can't get a reception to communicate all the details to the emergency services in time, then you or others could very well die.
And, as opposed to batteries which due to chemistry reactions are more unpredictable and complex to lab-test for real world use, antenna design and reception quality can be easily tested in the lab before launching the product (RF engineer here), instead of blaming the users for "holding it wrong", so Apple gets no pardons from me on this life endangering fuckup.
Plus, the phones with battery issues that have actually exploded were not more than a handful, so the risk of you actually being affected was low but all were recalled and refunded vs iPhone 4's poor antenna design which would plague all the phones, all the time and instead of a recall you got a rubber bumper lol.
It's well known that Apple prioritizes thinness, aesthetics and industrial design over function and reliability which is ironic given how stupid the magic mouse looks when it's charging.[1] How Jonny Ive green-lit that is beyond me.
Source? Sound interesting!
Overall most of those companies have excellent track records, but I bet everybody still remembers the exploding batteries from Samsung. Meanwhile, Sony actually has a pretty spotty track record (depending on where privacy and safety overlap for you), but most people have forgotten the root kit scandal.
https://en.wikipedia.org/wiki/Sony_BMG_copy_protection_rootk...
> He kept insisting on completely bizarre design changes, and ridiculous cost cutting on design like using 2 cheaper through hole diodes in parallel instead of one a cent more expensive (did not believe my ears, the guy failed EE101 right here,) dispensing with NTC inrush limiters, removing safety caps (he did not know what they are for) and asked us to redo the mold 6! times in order to save some grams of plastic per run.
I've seen this happening plenty of times, too. The higher-ups in many consumer (and even non-consumer!) companies are 100% clueless about these things, but they "know" that Chinese OEMs try to "rip you off" on designs, so they will demand their staff to squeeze them (and will promptly fire or replace anyone who dares tell them that a design is actually okay).
So every once in a while one of these smart guys will show up and make completely stupid demands. And explaining someone who doesn't understand basic electrical engineering concepts just why these demands are stupid is completely unproductive -- they don't just lack an understanding of the jargon, they lack an understanding of the most basic concepts. It's akin to trying to explain someone who doesn't know what a for loop is why you're using a hash table in a place where "a simple array would suffice".
Obviously still ridiculous when talking about charger safety but it’s important to remember we only see one side of the story here. Who knows what actually happened. I’ve worked with talented EE engineers on the client side complaining about how the contractor fucked up a board layout, wired things up incorrectly, or swapped out for cheaper “equivalent” parts that were out of spec in some incorrect way.
Branded siemens, and ericsson chargers for phones were $100+ circa 2001
If this charging block was from the Kindle, you're looking at significantly higher volume & several years of advances that drive the cost down. Additionally, since everyone has shifted to stock USB chargers, all chargers have gotten drastically cheaper due to scaling. You can buy a wall USB (C or A) charger for a few $ MSRP which means it costs like 20-50 cents for the components that go into it.
Makes me think I could intentionally ask for 1 or 2 stupid things, and see if the supplier tells me about it?
Now, because of your reply, I found this old HN post:
"Why Van Halen's tour contract had a "no brown M&M's" clause"
Just an idea, would it be possible to ask suppliers to jack up prices of THT power diodes so price follows forward current rating?
Right now the only incentive they have is to give you a part that just barely won’t break for the absolute cheapest amount.
As a side benefit this would weed out the bad suppliers and the good ones will seek you out.
Apple is probably the most cargo-culted company out there, after Google maybe. The number of "Steve Jobs wanabes" that I met who didn't have the billions nor the string of successful products behind them was staggering. I have no doubt Tim Cook is cargo-culted as much as Jobs was.
For anyone attempting this, keep in mind he built a team of world class experts around him.
Indeed, any kind of specialized skills suffer from the same problem, when you want to cut costs.
You can only get what you paid for.
(and I’m not saying paying for is a sufficient guarantee either...).
Well, technically, once the first one burned out he still had a spare ;)
You should have insisted on current limiting resistors in series :)
On another note, I can see a small business in selling matched pairs of diodes...
Hah but that will make it cost 0.0005 more per unit, can't have that
> ...years later I found out that the design of the first Kindle charger exactly matched...
So your employer's client was Amazon?
I don't believe they could've reused the design for some other client.
I've seen many guys like Tim Cook, most worse off ones.
He squeezes suppliers, and know what he is doing.
Others squeeze suppliers, and don't know what they are doing.
On one of my first jobs, I've been witness to one such negotiations down to single cents, and microns of plastic for a few million units customized charger order.
The order was such a whopper for a small sourcing agency, that higher ups were willing to do just anything to not to spook the client.
Our guys quickly understood that the consultant guy doing negotiations on behalf of the client was a round idiot with a level of engineering knowledge of a first year dropout.
He kept insisting on completely bizarre design changes, and ridiculous cost cutting on design like using 2 cheaper through hole diodes in parallel instead of one a cent more expensive (did not believe my ears, the guy failed EE101 right here,) dispensing with NTC inrush limiters, removing safety caps (he did not know what they are for) and asked us to redo the mold 6! times in order to save some grams of plastic per run.
We managed to at least push back on safety critical parts, on a point that it will fail the certification.
Many years later I found out that the design of the first Kindle charger exactly matched the one we did in everything, but having an extra label.
And 5 years ago I learned that Kindles had multiple issues with melting chargers, and safety recalls.
9 out of 10 companies in the supply chain will just shoot themselves in the foot if they go on doing it like that.
Nobody will point how unreasonable your demands are if you are a giant multinational corporation, moreover so in China. If you do this, and don't know yourself if you are asking a for something stupid, who will know? No one will.