Toshiba 2SC3281/2SA1302 - Are these fakes? - Page 9 - diyAudio
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Old 8th December 2012, 02:06 AM   #81
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Quote:
Originally Posted by unclejed613 View Post
unfortunately, the pokice and even city government officials will not understand the reasons the transistors are fake. it would be better to find out what government agency (if any) investigates this type of fraud, and report it to them. if you could have the parts tested by a company that does this, and send a copy of the test report and your sales receipt to that agency, they just might have something to work with. or you can write a blog, naming names, and get it listed on a search engine, so that when somebody looks up that company online, one of the first things that pops up in the search engine is your blog article with a title "ACME Components sells fake transistors"
Hello
You 100% right. Sometimes the police or local government protect the business because they pay more TAX than me or you.
Also they have no clue about is it fake or not.
The store say the chip is smaller because today they use better technology etc.
Better just to boycott them simple not to buy from them.
I bought 4 pair Toshiba and all fake.
Also before they sold Sanken and that was fake to.
To understand them in away they buy their component where is cheaper so can stay in business.
Otherwise they can not stay in business if you com pare them to Mouser or other large distributors.
Any store in Toronto if you buy semis there is no exchange or refund. Not even if you left the store and after few sec or min. changed your mind and you return.
They will say you changed the parts so they do not take it back.
Also they used to say, when you tested you damage the component that is your fault.
You need real legal help to take them out from business.
I know several electronic surplus store in Toronto or area many of those 85% run by Chinese people!
Sometimes if I buy small BJT's I take my DMM and measure those in the store.
If they say something I answer, you do not take back if the parts I pay bad so if I can't test it I do not buy it.
The do not like it.
I had several confrontation with them.
If you ask them if these or that is orig they say they get where the large distributors get their components.
I see on Ebay someone we all know here at the forum "Umut" sell Toshiba 2SC2500 etc, picture from the package with writing on, designed in Japan & assembled in Japan. No longer Made in Japan why??
Greetings Gabor
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Old 8th December 2012, 09:26 AM   #82
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Toshiba's main transistor fab. is in Thailand. If you want to buy genuine product from authorized distributors at lowest prices, you have to do business in S.E Asia or establish commercial trade links with their corporate sales networks in major distribution centres.

Frankly, they are difficult for small traders to deal with, so I prefer to deal with Fairchild who also made these parts under license but now market under their own part numbers.
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Old 8th December 2012, 09:42 AM   #83
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Since datasheet of these tranies specify what exactly the VCEBo for the device, if we slowly increase the current limited voltage acrross C and E while B remain open, can we trace the behaviour of the device and compare it with its actual anticipated data? Is this a good idea to verify the authenticity of any transistor?
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Old 8th December 2012, 11:31 AM   #84
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Normally, a high impedance DC voltage source is applied across transistor C-E and C-B to measure Vceo and Vcbo. The breakdown voltage is simply measured directly with a DVM and the current is limited so as not to cause damage.

The problem is that BVs vary widely even in genuine good product so not only do they not characterise a product but it's quite easy to make fakes that meet any minimum specification. The current and linearity are more of the issue and these are difficult to test outside a laboratory or well-equipped workshop.
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Old 8th December 2012, 09:03 PM   #85
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i've mentioned in another long-running thread on this board, that the best way to test these devices is comparison of Cceo and Ccb against a known good one both the individual capacitance measurements and the ratio between the two should be within +/-10% of the known good one.. you could also measure the beta at various Ic levels and see if it's what the data sheet says it is. the beta curve for the C5200's and other often-counterfeited devices is fairly flat up to 3 or 5 amps, where the fakes will have a 10:1 to 100:1 beta droop.
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Old 8th December 2012, 09:53 PM   #86
pooge is offline pooge  United States
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Quote:
Originally Posted by Ian Finch View Post
Toshiba's main transistor fab. is in Thailand. If you want to buy genuine product from authorized distributors at lowest prices, you have to do business in S.E Asia or establish commercial trade links with their corporate sales networks in major distribution centres.

Frankly, they are difficult for small traders to deal with, so I prefer to deal with Fairchild who also made these parts under license but now market under their own part numbers.
Do you know the Fairchild part numbers?
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Old 9th December 2012, 03:19 AM   #87
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FJL4215, 4315 are still manufactured and very close, IMHO.
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Old 9th December 2012, 04:19 PM   #88
pooge is offline pooge  United States
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Originally Posted by Ian Finch View Post
FJL4215, 4315 are still manufactured and very close, IMHO.
Oh, your talking the power transistors. I assumed you were referring to the transistors that are the subject of this thread.
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Old 9th December 2012, 08:20 PM   #89
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I guessed you were interested in the 2SC3281/A1302 power transistors but this thread has been drifting to 2SC500/A1943 since about #65.
Toshiba stopped manufacture of the OP pair too many years ago.

I think the options are pretty well known - Highly suspect NOS or On-semi clones.
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Old 9th December 2012, 09:54 PM   #90
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oops, 2SC5200, not 500.
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