#1070

Рет қаралды 9,487

IMSAI Guy

2 жыл бұрын

Episode 1070
I wanted to see if even the oldest cheapest op amps are being faked
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Пікірлер: 94

@KeriRautenkranz 2 жыл бұрын

Those aren't fake opamps but rather specially made mil-spec special jamming signal generators that cost the US military $37,645.38 each (in 100,000 quantity) . When the original equipment was retired, they went onto the surplus market but found no takers, so they were hastily remarked and foisted off on innocent Chinese parts suppliers.

@____________________________.x 2 жыл бұрын

We need a list of Chinese suppliers that don't sell fakes, this kind of lottery is tedious

@gregvanpaassen 2 жыл бұрын

At this point, my rule is "don't even think about buying any component that shows on a schematic via eBay/AliExpress." Prototyping board, OK. "5 watt" resistor? Nope. Banana jack? Roll the dice for a double-six. The reputation of an entire country has been permanently ruined.

@____________________________.x 2 жыл бұрын

@@gregvanpaassen it’s a shame that the haven’t noticed that Western culture relies on trust, they could be more profitable if they tried to build a brand rather than being “AcmeShop127598”. But if everyone else in their supply chain is trying to scam the next guy, then it’s just a bucket full of crabs

@Bobo-ox7fj Жыл бұрын

For the ones that sell retail? None. The only parts you can trust come from in-house suppliers for major offshore companies. Critically owned and OPERATED 100% by representitives of the parent company.

@spudhut2246 8 ай бұрын

Well said@@gregvanpaassen - we have destroyed ourselves on the backs of politics.....disgusting. how will we ever recover. We were once a great country that made amazing products, high quality, reliable.... Im afraid we couldnt manufacture ourselves out of a wet paper bag.

@tvelektron 2 жыл бұрын

Interesting... the waveform loks a bit like LM358/LM324 or similar types designed for single rail power supply...

@waltergeeraert3667 Жыл бұрын

I too have received many fake opamps through Aliexpress. Out of annoyance I was forced to design a few test PCB's with many jumper settings for multiple test configurations. And later for multiple opamp footprints. Occasionally received money back, but sometimes a dumbass on the other end who simply claimed: "show with photo that you received something DIFFERENT." No, the imprint is OK, but the contents of the chip are NOT! It does NOT conform to the datasheet. I made a story of it on a handmade website with a lot of test info. On the first line an option to activate Google translate. A link won't work, so Google "opamp test PE1ABR"

@englishrupe01 6 ай бұрын

Great info on your site for all the community. Many thanks, Walter.

@markopinteric 26 күн бұрын

Can you share some thoughts on how to do basic testing of OPAMs using a multimeter and a simple oscilloscope? I couldn't find your site with the above content.

@SeanBZA 2 жыл бұрын

I can see a use for them, use as effects pedals, to give a unique distortion to your guitar pedals. No need for all those fancy expensive diodes and such, plus layout, simply plug in a different IC and get a different sound.

@EngineeringVignettes 2 жыл бұрын

The pedals are going to need a cool product name. How about "Chinese Sawdust" ? (If curious, ask me about origin of the term sawdust)

@SeanBZA 2 жыл бұрын

@@EngineeringVignettes I guess you got a few of those epackets that were just filled with sawdust, used to generate false reviews for scummy stores, who would send these tracked packets to random addresses to build up a good standing on the big ecommerce platforms, so they could run the proper scams and vanish before the platforms started to get all the complaints in about shoddy goods, counterfeit or non delivery, and then simply open up new accounts again.

@EngineeringVignettes 2 жыл бұрын

@@SeanBZA - Nope. Back in the earlier days of car sales, some disreputable used car salesmen used to put sawdust in the rear drivetrain trans-axles of an old clapped out car (the "rear-end") to make it seem as it were in better shape than it really was. Hence the term "filled with sawdust". :) Cheers,

@frankowalker4662 2 жыл бұрын

I thought exactly the same thing. :)

@SeanBZA 2 жыл бұрын

@@EngineeringVignettes Here it was more common to use banana peels, as they were easier to put in through the hole, and did the same keep it quiet for a few months thing. Plus of course they were easier to get hold of, and would not look out of place in a salesman's desk drawer, either he was going to eat them, or he did not want to put the peels in the bin.

@cellularmitosis2 2 жыл бұрын

Great idea checking the resistance!

@tiftik 2 жыл бұрын

The output waveform has a very telltale crossover distortion. This means it's a class B output op amp optimized for low quiescent current. 741 should have a class AB output with no obvious crossover distortion. LM358 is quite common for these fake op amps, but only decapping can tell for sure

@mariomionskowski6223 2 жыл бұрын

Really nice Video, what you do makes sense, simple and good.

@paulcohen1555 2 жыл бұрын

Don't be surprised amazed etc. I already got from them IC's that I believe there wasn't any silicon inside the package.

@meesterdinglefritz2064 10 ай бұрын

Just came across your channel, great stuff! Subscribing. Godspeed!

@727jetjumper 2 жыл бұрын

I don't understand why they're doing that. Seems like a quick way to have your company permanently associated with fake poo.

@SeanBZA 2 жыл бұрын

Well, random seller and random buyer, seller likely bought a fw hundred, and next month will open another account to sell them again, using window washing to get some legitimate looking feedback for a month or two, then slapping on the fakes for 3 months, which is about the time the complaints start to come in, and the store is no longer active to grab money from.

@mdofxds 2 жыл бұрын

Some time ago I stumbled upon a bunch fake NE5532s. I ran into weird measurement results while tesing a simple audio mixer I was building. After some investigation I discovered that those opamps in fact were LM358s re-marked as NEs.

@urugulu1656 2 жыл бұрын

reminds me of getting 595 shift regs that were open collector outputs instead of push pull. had me scrambling for a while

@kapioskapiopoylos7338 2 жыл бұрын

ok this thing is still in production, why on earth are people buying them from china for 1$ 100pcs free shipping? Get them from a half decent source (yeah they may cost 10x more but is it worth your time?).

@IMSAIGuy 2 жыл бұрын

$0.90 at Mouser

@spudhut2246 8 ай бұрын

Holy cow....this is the 4th video you have done on garbage parts. What would you recommend where to get them or is each purchase a gamble. Im new to this and am looking to get some parts in inventory; like IC parts, capacitors, etc. Where would you recommend to get them (in bulk and different values? ) Thank you for putting these videos out....I see now how much good it is to have a Oscope and other testers on hand.

@sebastian19745 2 жыл бұрын

It may be a single rail power supply opamp. However, I think it can be used as a comparator, just because you have it at hand. To throw them away I think is kinda extreme if they can be used at something.

@IMSAIGuy 2 жыл бұрын

single supply part makes sense.

@loukashareangas4420 2 жыл бұрын

I always thought that fake pricier opamps were just LM741s. What chip do you put inside a fake 741 package?!?!? Rejects probably...

@EngineeringVignettes 2 жыл бұрын

2 transistors in a long-tailed pair circuit?

@SeanBZA 2 жыл бұрын

Rebadge any DIP8 part you found in the market place, blacktop and print whatever the customer order says. If your cost is 0.1c for the pack of 10 chips, 0.1c for the blacktop and laser etch, you can make a profit if you do 100 orders of 10 a day.

@johnlegros1586 2 жыл бұрын

I think that these opamps are in fact 741 original but from a batch rejected during manufacture and ment for the bin...and someone found the bin and recycles them...this does happen even on complete smartphones , it is a pain in chinese manufacturing management....

@aaa000777 2 жыл бұрын

I don''t think those are cloned op-amps. I think they are genuine, but genuine factory rejects. Someone is raiding the dumpster and re-selling them at the factory.

@RexxSchneider 2 жыл бұрын

I agree completely. There's just no opamp made that has a spec that would tolerate the offset cross-over distortion that chip had with just a x10 gain. They are simply faulty, and somebody's found a way of monetising rejects. Looking at the idea of finding a use for them, it's clear they can't be used in any linear application. But what about switching applications? It might be worth determining how much current the output can source and sink. If it's not crippled, then it might be usable to drive LEDs or maybe relays. Will it work as a comparator? If the differential range without lock-up is big enough, it could be used as a square-wave oscillator, a Schmitt trigger, a level shifter. buffer, inverter, etc. All at low frequency, of course.

@aaa000777 2 жыл бұрын

@@RexxSchneider , the problem with re-using them is that each would need to be tested to find out what the actual fault it has is. I am sure that there are probably common failures but you would need to match up the failure with your application. In todays world of time is money it doesn't seem practical to do this.

@EngineeringVignettes 2 жыл бұрын

It does not explain the lack of a bonded offset pin though...

@RexxSchneider 2 жыл бұрын

@@EngineeringVignettes Not all single opamps have offset null pins. These rejects could be from almost any opamp, not necessarily a 741.

@SeanBZA 2 жыл бұрын

@@EngineeringVignettes Who says they were a 741, plenty of single opamps in the DIP8 package either have no offset adjust capability, or it is only done on die, and thus no bond wires. Just made to fit an industry standard pinout, and having 3 non connected pins is acceptable when there is literally no difference cost wise in the leadframe, to have all 8 pins there, and simply not bond them to the die. Could even be reject dual and quad opamps, that were manually bonded to use the one "sorta good" part of the die, because they got the reject dies for scrap silicon price, had a tester that could do the chip probing, and a manual bonder and staff. Just have to make sure you have 10 000 parts ready in the line before you start up the second hand die mould machine you bought, and use the cheapest epoxy with.

@craign8ca 2 жыл бұрын

I suppose you could use them as comparators.

@arlipscomb 2 жыл бұрын

I had a "Chinese fake" voltage regulator cook a Atmel processor and a number of support chips. Maybe those op-amps were QA rejects? Who knows. Even just playing around I don't have time (or money) to spend dealing with bad chips or other parts.

@aduedc Жыл бұрын

It is interesting, but lets characterize these opamps. I designed many opamps for large semiconductor companies, and there is not much in designing an opamp, it is a mundane task now days. I think the problem is that they use new processes for the old design. Their foundry process might have lower maximum voltage devices, and they probably are using a digital foundry process for analog circuit. The first thing I test is that I lower the supply voltage to see if we can get ride of kink in curve. Second, the graph you have in your hand is block diagram not actual design schematics. The offset correction resistors could have been replaced with two current sources, ie. current mirrors. So for offset cancellation test you should use it in voltage buffer, ie. negative input connected to output and positive input connected Vtest, to see if you can adjust the offset. Also for frequency response connect a white noise source at the input and connect the output to spectrum analyzer, or oscilloscope with FFT, to inverting configuration with gain of 10 to see the frequency roll off.

@1kreature Жыл бұрын

Should you not do that Pin 4 to 1/5 test at the other polarity? Pin 4 is -v after all, not +v ?

@carlospenalver8721 9 ай бұрын

If they float can’t you stick them in the tackle box for fishing ?

@d46512 2 жыл бұрын

The difference between clone, fake, counterfeit, and poor quality parts is one of intention. The key point is that no-name parts may not meet the specifications. Caveat emptor.

@T-Tronix 2 жыл бұрын

Many years a go I visited semiconductor fab where friend of mine was working. He showed me where all the silicon that don't meet the specified spec go. Alibaba. He said many companies sell the Ics and silicon that don't meet the spec to Chinese companies where they just badge them as normal part and sell on alibaba. Why bin them when they can make some money on them. As with alibaba there are 3 kind of part. Out right fake which are not even the part you ordered as they been just re badge parts. Parts that don't meet the spec. And old parts that been salvaged cleaned and re packaged as new part.

@pisotones2348 2 жыл бұрын

I found the very same problem with some TL081 I got included in a chinese kit.

@franciscoferreira-eh1yu 10 ай бұрын

Same here with a Power supply kit.

@guitchess 2 жыл бұрын

The conspiracy theorist in me almost thinks it's intentional. If beginners are discouraged by bad parts, there's less competition later. Plus, factories can hone their process and recoup a little of the cost of culls .

@spudhut2246 8 ай бұрын

exactly....it adds much confusion.

@rockpadstudios 2 жыл бұрын

maybe as a comparator

@johnwest7993 11 ай бұрын

Just as long as they don't fake resistors.

@IMSAIGuy 11 ай бұрын

Oh I'm sure the wattage rating of those thin leaded skinny resistors is up to snuff.

@MsFireboy2 Жыл бұрын

Question have heard of or used the uA709 op-amp?

@IMSAIGuy Жыл бұрын

sure, it is a very old design

@MsFireboy2 Жыл бұрын

@@IMSAIGuy Question I just found some interesting information on Curve Tracers. In the February past edition of Electronic Servicing page 38 there’s a really in-depth article on the Judd Williams curve tracer. I thought you might like to view it?

@mineown1861 2 жыл бұрын

Is nothing sacred . I saw ten OPA627 for $11 with free shipping , it made me laugh but to think they'd fake the humble 741 is just sad .

@artursmihelsons415 2 жыл бұрын

That one LM741 was real garbage! Probably, even power specifications isn't as specified in datasheet.. Fake op amp burnout request for fun! 😉

@twotone3070 2 жыл бұрын

"Does faking a 10c OpAmp with a 5c OpAmp make any sense at all?" Yeah, 5c.

@Bobo-ox7fj Жыл бұрын

5c times ten million AND you have no cull, just sell the duds too

@peatmoss4415 Жыл бұрын

Most of the ICs I got from Amazon are fake. Found out too late to return them....

@PeetHobby Жыл бұрын

Don't buy parts that aren't made in china form chinees sellers on ebay, big chance that they are fake(clones or cheap parts that are renamed) or part that were rejected parts that have defects, and if they are real you will pay more than if you would buy them from one of the big international wholesalers.

@johndavis1465 Жыл бұрын

They are rejects that are not labelled then labelled later

@IMSAIGuy Жыл бұрын

no, they are odd Chinese designs labeled as familiar products. there is about 13 Chinese opamp designs that show up.

@bfx8185 2 жыл бұрын

This is great video from you. My suggestion you should shortened your video. You are so smooth-talking I started your video at around 3 minutes. Keep that in mind;)

@__--JY-Moe--__ 2 жыл бұрын

what would help me, is a ''new'' stock replacement!! like from Texas Instruments/TI !!... super vid as always ! wowee! is that a whole pile of fet's in that chip? BRUH? ''they'' clone anything they see!!! every modern electronics board? cloned!!! any circuit? cloned!! all cloned!! environmental pollution?? what's that...look inside!! probably using steel, in replace of doped pads!!

@bruceblosser384 10 ай бұрын

How can you know what is bad, before you buy???

@IMSAIGuy 10 ай бұрын

you have to buy from a dealer like Digikey or Mouser

@franciscoferreira-eh1yu 10 ай бұрын

What sucks to me is that mouser charges 40usd to mu country in freight only. On top of that I need tô pay around 98 percent in tax calculated using product cost plus freight cost. The good side I get It in less than 30 days with the absolute sure It will bê original. Each day that passes I love my country less

@mortenlund1418 9 ай бұрын

Where are you from? If you are into electronics and stuff we have a need for you in Europe! @@franciscoferreira-eh1yu

@coltronex 2 жыл бұрын

Are they fake or just factory drop-outs?

@IMSAIGuy 2 жыл бұрын

fake

@BryanByTheSea 2 жыл бұрын

What I don't understand is how they are faked, are they having semi's made with a altered die and mfg cheaper, or a similar chip that is remarked.

@IMSAIGuy 2 жыл бұрын

they use one of a dozen different chinese opamp chip designs

@BryanByTheSea 2 жыл бұрын

@@IMSAIGuy .. buying a cheaper chip, changing the package markings and reselling? or actually manufacturing with a common cheaper die that is available. I suppose a higher end opamp the die is not available for them to copy, thus why substituting a jelly bean die and trying to pass off as the real?

@bobkozlarekwa2sqq59 2 жыл бұрын

Chinese op amps - good, fast, cheap - you can choose any two of the three! If you need good fast op amps a they won’t be cheap! If they are cheap and good, they won’t be fast …..

@SeanBZA 2 жыл бұрын

You forget that you can choose anything, and you will get cheap as standard product.

@toddanonymous5295 2 жыл бұрын

Even PolyPacks did better than these. They must have gone from the dust pan to the shipping container. Or maybe they are a product of Hunter Electronics .

@boonedockjourneyman7979 2 жыл бұрын

Thanks man. I thought my skills were fading. Now I’m getting - getting worried - these animals have no morals, ethics, integrity, etc. when do we shut off all trade with them? I used no identifiable names. If Google cancels me, you know who they work for. Google is the enabling entity of these - things.

@WolfgangMahringer 2 жыл бұрын

I think you are doing it wrong...pin 4 should go to the black lead of your ohmmeter. You had the red lead on Pin 4, so you measuring parasitic diodes to the substrate of the chip. But anyway, the ebay-741s are fakes, that's for sure.

@IMSAIGuy 2 жыл бұрын

you can measure a resistor red/black or black/red don't matter

@WolfgangMahringer 2 жыл бұрын

@@IMSAIGuy If you measure a single resistor, then yes, polarity doesn't matter. But here you're measuring a resistor paralleled with transistors on a substrate, a TOTAL different thing! Try it!

@IMSAIGuy 2 жыл бұрын

@@WolfgangMahringer if you say so, what I see is an isolated resistor

@IMSAIGuy 2 жыл бұрын

OK, I did it and yes there is a differnence but not enough to care about 650ohm vs 750ohm

@WolfgangMahringer 2 жыл бұрын

@@IMSAIGuy Thanks for proofing my point. If that 1k on the pins would be like a 10k or so, it would be a different ballpark. Maybe 8k correct polarity, still 750 reversed. And no, the resistor is NOT isolated. It is on a substrate together with semiconductors, and thus will conduct (parasitic diodes) in one direction.