How manufacturers cheat - [photo prefered] - Page 1
Forum section: electronics / general

author: nardev
author_rank: Unknown
timestamp: October 22, 2013, 05:15:21 pm
content: I haven't seen such a topic on this forum, i believe that many of us have similar experience.I start with this photo that i came across..

author: Anks
author_rank: Frequent Contributor
timestamp: October 22, 2013, 05:24:54 pm
content: That photo has been doing the rounds for years. Some people do that to keep the old cans in vintage amplifiers to maintain the look.

author: mariush
author_rank: Super Contributor
timestamp: October 22, 2013, 05:36:42 pm
content: This first one is not exactly "how manufacturers cheat", it's more of a counterfeitFake hdd :A fake Samsung SSD:Album :http://imgur.com/a/i7PBS#XhHsNSomeone bought this in Russia:This one though is manufacturer cheat... fake pfc chokes:http://www.cloudfrom.com:8080/showItem/showDetail/10680033.html

author: jaxbird
author_rank: Frequent Contributor
timestamp: October 22, 2013, 05:37:27 pm
content: If it's a genuine Rubycon, I would assume those much better capacitors, even at lower value and voltage, than a "Master" branded capacitor

author: Phaedrus
author_rank: Frequent Contributor
timestamp: October 22, 2013, 08:32:47 pm
content: Buy a generic (non-major brand) $20 computer PSU, open it up, and count how many missing components there are.

author: senso
author_rank: Frequent Contributor
timestamp: October 22, 2013, 09:15:30 pm
content: A sucker is born every minute..Oh look something that costs 500€ is going out on ebay for 20€, it must be true

author: Stonent
author_rank: Super Contributor
timestamp: October 23, 2013, 12:09:14 am
content: Well officer when he gave me change he assured me it was valid currency for this area!

author: nctnico
author_rank: Super Contributor
timestamp: October 23, 2013, 01:09:05 am
content: I just ordered one of these. I don't expect it to be genuine though:http://www.ebay.nl/itm/230814470951

author: Kryoclasm
author_rank: Regular Contributor
timestamp: October 23, 2013, 03:50:33 am
content: Quote from: nctnico on October 23, 2013, 01:09:05 amLooks like a genuine Sun Yuong Chinese 10 turn pot to me.Am I not seeing what you are?

author: nctnico
author_rank: Super Contributor
timestamp: October 23, 2013, 07:52:04 am
content: The part number they quote is from Bourns. Other sellers sell similar looking pots which say 'Bourns' on the rear. I expect the one I'll receive in a week or three will also say its from Bourns.

author: AndyC_772
author_rank: Super Contributor
timestamp: October 23, 2013, 08:03:27 am
content: Well, OK, it's a Bourns part number, but is that really so different from any other part which is available from multiple sources? Is a Fairchild 74HC00 device a "non genuine" Texas Instruments 74HC00? (And no, I don't know, or care, which came first!!)

author: tszaboo
author_rank: Super Contributor
timestamp: October 23, 2013, 08:22:58 am
content: Fake datasheet information, reference voltage drift is 250 times the advertised:http://nandblog.com/why-i-dont-fully-trust-datasheets-anymore/From ANALOG DEVICES!

author: Unknown
author_rank: Unknown
timestamp: October 23, 2013, 08:30:32 pm
content: Are you complaining that your design failed because the parts weren't all better than the typical spec in the datasheet? If you relied on typical specs without testing every part, then you got what you deserved.The 50 ppm figure is specified at 125°C, the 0.2 ppm figure at 25°C, so they don't directly contradict each other. They probably measured at 125°C and originally extrapolated to 25°C, and in the new version they directly quote the 125°C figure because extrapolating to 25°C might be unreliable. So I see no evidence for your claim that the drift is 250 worse than advertised.

author: staxquad
author_rank: Frequent Contributor
timestamp: October 24, 2013, 02:17:13 am
content: Quote from: Stonent on October 23, 2013, 12:09:14 amSome unscrupulous whomevers purchase goods and services from villagers in 3rd World countries using Canadian Tire coupons. Needless to say that paper ain't convertible currency. I feel bad for the poor people who get scammed thinking it was Dollars, not knowing it was Cents, and worthless coupons outside a Canadian Tire Store in Canada. Well...it feels like paper money

author: tszaboo
author_rank: Super Contributor
timestamp: October 24, 2013, 11:58:36 am
content: Quote from: alm on October 23, 2013, 08:30:32 pmI was lucky enough that I meet the newer datasheet. The 0.2 ppm would be spectecular, LTZ1000 category drift. They obviously measured at 125°C, but as I said, Linear technology actually measured the drift. And they were claiming 0,2ppm, and it was far worse. And the newer version of the datasheet said 250 times worse number for the drift.The first version of the datasheet (link on my site) clearly has a different number than the rest. And this is not a joke, someone had bad days because this.

author: Unknown
author_rank: Unknown
timestamp: October 24, 2013, 12:43:12 pm
content: The drift atT=125°Cin the new version of the datasheet is 250 times worse than the drift atT=25°C. It's not obvious from the datasheet how much worse (if any) the drift at 25°C would be if measured properly. The LT DN quotes numbers that are much worse, but I think they only tested a few samples. If they specified a maximum drift then I'd agree with you, but relying on individual parts not to be (much) worse than the typical specs is very dangerous. I didn't see a histogram for long term drift, so there's no way to know how broad the distribution of the long term drift is. Maybe the median was 0.2 ppm but 20% of the parts were worse than 20 ppm? Maybe in some batches all are worse? It's not a guaranteed spec, so the production tester is not going to reject parts for high long term drift (this would be extremely expensive). If you rely on the spec, get a part with a guaranteed maximum drift spec (if there is such a thing), or do the selection yourself and burn them in for a month or so and measure the drift (this is what companies like Agilent do).

author: elex_enthusiast
author_rank: Regular Contributor
timestamp: October 24, 2013, 02:12:06 pm
content: Quote from: mariush on October 22, 2013, 05:36:42 pm