Chinese Parts

[ekg98]

I am new getting into this hobby.  I have some parts I have got from Mouser and Digikey also other legitimate sources.  I have also purchased some 555, 556, 4017,4060,4013,LM386, 78xx regulators, etc from China off aliexpress.  Resistors and capacitors and leds too. 

What is the quality of these components and the reliability like.  Should I avoid them for future purchases?  Whats the story on them.  I have not had a problem with the 555 timers but have yet to try out the rest of my new stash.  I indeed have some legitimate TI parts and some of the ones I got from China.  Yes the silk screening looks different and the die may even be different but do these items function the same.  Obviously you wouldn't want to go to the moon with them but for goofing around and making stuff like games and clocks etc are they perfect to use?  Its hard to ignore spending $5 dollars and getting something like 12 chips vs spending $1.30 and getting 50 of them.

What books do you guys recommend.  I am trying to get my hands on a copy of the CMOS cookbook.  I hear this is a good book for CMOS chips.

Thanks
William

[paulca]

There are many threads on this.

Regards quality, the gist is: You just don't know.  You take the risk.

Some of the parts are genuine, just skipping out all the middle men and marketing and buying from the Chinese shop down the street from the factory.

Some are seconds dumped by the original factory due to failing tolerance tests, quickly snapped up and listed on ebay.

Some are clones which have almost the right spec and will be good enough for hobby stuff.

Some are down right fakes which won't work as expected.

There is ZERO quality control.  They pack broken ones along with good ones as they don't test anything.

So if you are buying them for hobby work and the fact the tolerances might be out by a few % doesn't bother you and you are not worried that a batch of components turns up dead on arrival once in a while, go for it.

ALWAYS check the reputable sites first for price.  I got caught on a drunken ebay stint over Christmas when I ordered an ATTiny85 off ebay for £3.85 shipped.  They are £1.036 free delivery from RS Components!  Doh!

One use case I try and avoid using cheap Chinese ebay stuff is anything that runs on mains and I want to run 24/7 when I'm in or out.  I have had Chinese clone modules smoke and burn on the bench, I don't want a 12V AC/DC wall adapter doing the same while I'm at work.

[edavid]

What books do you guys recommend.  I am trying to get my hands on a copy of the CMOS cookbook.  I hear this is a good book for CMOS chips.

Ugh, no.  It has almost zero useful information in it.

[wraper]

I have also purchased some 555, 556, 4017,4060,4013,LM386, 78xx regulators, etc from China off aliexpress.

Most of those likely are counterfeits but LM386, 78xx are almost guaranteed to be counterfeits.

What is the quality of these components and the reliability like.

Crap quality, opamps having completely different specs, voltage regulators not able to supply rated current and failing.

[ekg98]

Any recommendations?  Looked like a fine book when I read a few pages.  I mean I don't even know the whole family of chips and don't even know what 1/4 of them do.

[ekg98]

I figured the case but I thought I would ask.  However I doubt most of the components on mouser or digikey are priced correctly.  Seriously they are making 1000% profit on some of these chips.  Lots of 25 of particular chips would be great but at reasonable prices.  Not $10 per ic type just for 25 chips that's ridiculous.  BGMicro is better and cheaper shipping but they don't have a super great selection of 4000 series.

The price difference is so great.  I am just making doodle widgets that make noise and blinky lights.  Plastic models and small gadgets.  I can risk the duds and failures and flames and smoke and still come ahead after mouser and digikey rape me.

I have also purchased some 555, 556, 4017,4060,4013,LM386, 78xx regulators, etc from China off aliexpress.

Most of those likely are counterfeits but LM386, 78xx are almost guaranteed to be counterfeits.

What is the quality of these components and the reliability like.

Crap quality, opamps having completely different specs, voltage regulators not able to supply rated current and failing.

[soubitos]

just make sure to NOT use potentially unsafe/fake or dubious parts in anything critical or life threatening and you will be fine.. if you must use such components, make sure to take any safety precautions possible and test them before final use. Most of the times you will get proper components but in several cases you will not... if the price is TOO low even for chinese counterparts, then be careful... i ordered a bunch of 10uf smd capacitors advertised as X7R 10% and when i got them they measured from 5-9uf obviously nothing even close to what i paid for then again, i paid less than for crappy caps from legitimate sources so no harm done (i lost time though)....


I think i got a copy of National Semiconductor CMOS family IC's book..... would cost a lot to ship though

[ekg98]

Yeah thats what I figure.  I can tinker with the cheapo ones.  If I break them so be it and if I actually make something I want to use on a daily basis.  Example a wall clock or a stop light in the garage.  Use real deal ones.  Yes for something in the garage or a clock.  Temperature ratings and accuracy are important etc. 

I made a set of dice that were powered off a 9v.  Example that could use cheap chinese crapo.  However imho anything with a clock no. 

Lol don't use them to submit any of my redesigns for the space shuttle guidance systems.  )))

just make sure to NOT use potentially unsafe/fake or dubious parts in anything critical or life threatening and you will be fine.. if you must use such components, make sure to take any safety precautions possible and test them before final use. Most of the times you will get proper components but in several cases you will not... if the price is TOO low even for chinese counterparts, then be careful... i ordered a bunch of 10uf smd capacitors advertised as X7R 10% and when i got them they measured from 5-9uf obviously nothing even close to what i paid for then again, i paid less than for crappy caps from legitimate sources so no harm done (i lost time though)....


I think i got a copy of National Semiconductor CMOS family IC's book..... would cost a lot to ship though

[dmills]

It also depends a bit on how you rate your time.

Particularly for a beginner, having something not work because some bugger has relabelled a transistor and the Base and Emitter are now swapped from what you expect can cause massive fault finding headache, even to the point of giving up. 
For a beginner I would actually say getting known good parts is more important then it is once you get a little experience with fault finding.

Regards, Dan.

[soubitos]

Dont reject them or underestimate them.. you pay far less than buying in the "west" and in many if not most of the time they are perfectly fine parts..... use common sense ie if you find a deal for a 10$ part for only 50c shipping included there is something off about it... So far, out of maybe more than 100-150 orders from China, i can honestly say i am disappointed from what was delivered 2-3 times... but i make sure to check everything i receive before using it... again.. for non critical applications, you are more than fine...

[paulca]

For a bit of research this guy's model is basically, make money on YouTube by making videos of him buying, opening and playing with cheap chinese electronics stuff and then uses the money to buy more cheap chinese stuff.



It's addictive!

There are some things you just can't buy from Digitkey/RS/Farnell.  You try buying a breakout board for a ADC.  They cost £250 upwards.  Similarly try buying simple things like heatsinks.  £5, £10, £20.  Panel voltmeter,  £60!  There are dozens of examples where the big resellers charge a fortune which puts the price point out of the hobby market completely, but the cheap chinese versions are 1/10th the price or less.

[bd139]

Yep. I’m still on the fence with China. I’ve got about 2000 parts winging their way to me now (or sinking after being dumped off a container ship) so will run some proper test cases. I have hundreds of LEDs, a soldering iron, voltage regulators, diodes, transistors, capacitors. Think the whole lot including iron set me back about £25. This is the value proposition.

Just need to test and know what to look out for.

I did find a seller who was selling packs of green blob Mylar caps which aren’t microphonic and of good tolerance (<5%) for less than one MKT1813 film cap from Vishay.

[soubitos]

I expect two packs with both pcb's and parts from JLCPCB/LCSC...
My first order of parts from LCSC went very bad in customs (they shipped EMS instead of registered airmail as requested and customs found my 92 euro worth of pcb+parts to be a128+15clearance fee+24$VAT)... but very well in terms of parts... they got "western"parts at good prices and also (my thing) good quality "brand" Chinese parts... well worth the try.. Buying on aliexpress though is a whole different sport... in a lot of cases i opt for a tested/trusted vendor instead of a slightly cheaper one just to make sure.... not so much for"jellybean" parts but certainly for IC's etc

[bd139]

ICs are risky. Had a few duff ones. I just got 10x AD8307 log amps for £3. They are £100 for the same here. Will see if they work or not!

[soubitos]

Quote from: bd139 on Today at 10:16:55 PM

ICs are risky. Had a few duff ones. I just got 10x AD8307 log amps for £3. They are £100 for the same here. Will see if they work or not!

They probably will work... but how they will operate spec-wise is your key question....
On the other hand, there are quite a lot of interesting chinese ic's

[ekg98]

I wish there was a seller that would release them as Chinese versions and give a datasheet.  I keep seeing MLLSE as a brand name but I don't know what it means.

[phil from seattle]

ICs are risky. Had a few duff ones. I just got 10x AD8307 log amps for £3. They are £100 for the same here. Will see if they work or not!

I probably wouldn't buy any AD stuff from China though, for that price, it's worth risking.

[bd139]

Exactly. I can test them well enough with signal generator and some inline attenuators so fingers crossed.

[Audioguru]

Genuine electronic parts bought locally are so inexpensive since money grows on trees (my government pays me a pension for me doing nothing) that I never buy cheap Chinese junk from ebay, Amazon or Ali.

[Tomorokoshi]

How much time do you spend:

1. Researching the circuit?
2. Designing the circuit?
3. Making the schematic?
4. Ordering the parts?
5. Laying out the parts?
6. Assembling the unit?
7. Testing the unit?
8. Debugging the circuit?
9. Fixing the circuit?

Now apply a wage rate for each of those times. Do the times differ due to the supplier of the parts? If there is x% of risk associated with a part being operational, how many total hours does that add to the work? What is the total cost difference?

[ekg98]

Yeah here its even worse than mouser or digikey.  The only place I know to get parts here wants anywhere from $1.20 to $3 usd per transistor.  I am speaking something like a 2n2222 or a 2n3904.

Genuine electronic parts bought locally are so inexpensive since money grows on trees (my government pays me a pension for me doing nothing) that I never buy cheap Chinese junk from ebay, Amazon or Ali.

[soubitos]

Local price for UNR (is that same as the chinese Uniohm?) 0.01 EURO each 5% smd resistor.....
Say i buy 10 values, 1000pcs each.... 10x1000=10000pcsx0.01=100 euro! shipping not included....
I got them from LSCS now, Uniohm brand 1% 1.3-1.4$ per 1000pcs total 14$ for 10000pcs ... shipping is steep 20+$ minimum BUT you get free shipping for parts if you also order pcbs (even a 2$+shipping~~10$ order)....
Even if i only order the damn resistors, its 30% of the local price.. and we are talking RESISTORS here.... jellybeanier than jellybean LOL!

If you live in EU remember this date... 2020...after that year, ALL packaged from China will pass through customs and you can expect the cost of electronic components to rise sky high

[JacquesBBB]

apart from the already quoted cases, you can also get parts from china that are sold as new, but that are
parts that have been scraped from old equipments and refurbished to look " as new".

These are easily detectable with some habit.

I would advocate to buy for hobby use  from china parts where you can easily see if its working or not  ( lcd  or oled screens for example, sensors, actuators, motors).
or mechanical parts.

Check the prices from reputable sources. Very often, electrolytic caps are not cheaper on ebay than on Mouser or RS.

Do not buy critical parts on ebay or aliexpress.

[wraper]

Local price for UNR (is that same as the chinese Uniohm?) 0.01 EURO each 5% smd resistor.....
Say i buy 10 values, 1000pcs each.... 10x1000=10000pcsx0.01=100 euro! shipping not included....
I got them from LSCS now, Uniohm brand 1% 1.3-1.4$ per 1000pcs total 14$ for 10000pcs ... shipping is steep 20+$ minimum BUT you get free shipping for parts if you also order pcbs (even a 2$+shipping~~10$ order)....
Even if i only order the damn resistors, its 30% of the local price.. and we are talking RESISTORS here.... jellybeanier than jellybean LOL!

If you live in EU remember this date... 2020...after that year, ALL packaged from China will pass through customs and you can expect the cost of electronic components to rise sky high

At TME (distributor located in Poland) For $5 you can buy a reel of 5000 1% Vishay resistors. Or Royal Ohm for $3. Next day EU shipping for around $9.

[ekg98]

And this is why I will never agree with the EU on anything

Local price for UNR (is that same as the chinese Uniohm?) 0.01 EURO each 5% smd resistor.....
Say i buy 10 values, 1000pcs each.... 10x1000=10000pcsx0.01=100 euro! shipping not included....
I got them from LSCS now, Uniohm brand 1% 1.3-1.4$ per 1000pcs total 14$ for 10000pcs ... shipping is steep 20+$ minimum BUT you get free shipping for parts if you also order pcbs (even a 2$+shipping~~10$ order)....
Even if i only order the damn resistors, its 30% of the local price.. and we are talking RESISTORS here.... jellybeanier than jellybean LOL!

If you live in EU remember this date... 2020...after that year, ALL packaged from China will pass through customs and you can expect the cost of electronic components to rise sky high