Rebranded transistors?
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From: pimpom on 18 Feb 2010 11:09 John Larkin wrote: > > http://www.eetimes.com/news/latest/showArticle.jhtml?articleID=222900688 > > John Sadly, it's true. Though, as I wrote in my reply to Jan's post, I've used many transistors marked as in his picture without observing any difference in performance. Even in India, Delhi, the nation's capital, is known as the capital of counterfeit products (counterfeits are called 'duplicates' in Indian English). It's why I avoid buying from Delhi-based shops and companies. This is not just in electronic components, but also in most other areas. A friend who owns a car repair shop once told me that they have a choice of several grades of counterfeit called D1, D2, D3 etc. The D' stands for 'duplicate', with D1 being the highest grade!!
From: pimpom on 18 Feb 2010 11:26 Jan Panteltje wrote: > > Maybe someone in China is just spray-painting a lot of > universal PNPs > :-) > And you also had some of those :-) A strong possibility. Maybe omitting the 'B' is an attempt to avoid legal issues rather than to increase character size: "We never sold this as a BCxxx"
From: Klaus Bahner on 18 Feb 2010 12:53 > and does not say 'BC557', but 'B557C': > ftp://panteltje.com/pub/strange_transistors/BC557_rebranded_img_1806.jpg Years ago (IIRC ~2002) I bought a batch of BC54x and BC55x from a renowned distributor, so hopefully this should guarantee that they were the original stuff. Those looked exactly as the one in your image. I'm not sure though, who manaufactured them, possibly Motorola or Philips. Judging from this I tend to say that these are not rebranded, but perhaps old transistors. > so I am not sure: > ftp://panteltje.com/pub/strange_transistors/BC557_top_img_1808.jpg I can't see on the image whether they are grinded or just cheapish molded. > > Other transistors (BC547) look totally normal from Conrad. > I got a bit supicious when one of these did not work as expected, > measured the beta, about 330 at low currents, but seems to drop to much lower at 100 mA. Seems quite normal to me for B-grade BC557. Of course these days, you can't be absolutely sure, but they are probably OK. Hth Klaus
From: Jan Panteltje on 18 Feb 2010 14:01 On a sunny day (Thu, 18 Feb 2010 18:53:14 +0100) it happened Klaus Bahner <Klaus.Bahner(a)ieee.org> wrote in <4b7d7e89$0$36573$edfadb0f(a)dtext01.news.tele.dk>: >> and does not say 'BC557', but 'B557C': >> ftp://panteltje.com/pub/strange_transistors/BC557_rebranded_img_1806.jpg > >Years ago (IIRC ~2002) I bought a batch of BC54x and BC55x from a >renowned distributor, so hopefully this should guarantee that they were >the original stuff. Those looked exactly as the one in your image. I'm >not sure though, who manaufactured them, possibly Motorola or Philips. >Judging from this I tend to say that these are not rebranded, but >perhaps old transistors. > >> so I am not sure: >> ftp://panteltje.com/pub/strange_transistors/BC557_top_img_1808.jpg > >I can't see on the image whether they are grinded or just cheapish molded. I tried to take a picture of the top that showed that, but you can only see it in some light. So that picture is not very clear. But you can, with a magnifying gllas, clearly see the traces of the grinding tool :-). >> >> Other transistors (BC547) look totally normal from Conrad. >> I got a bit supicious when one of these did not work as expected, >> measured the beta, about 330 at low currents, but seems to drop to much lower at 100 mA. > >Seems quite normal to me for B-grade BC557. > >Of course these days, you can't be absolutely sure, but they are >probably OK. So far I have used a few, normal things work. Some application that pushed it a bit needed modification... Could be my circuit too :-) >Hth >Klaus >
From: TTman on 18 Feb 2010 15:00
"Jan Panteltje" <pNaonStpealmtje(a)yahoo.com> wrote in message news:hljk7e$9v$1(a)news.albasani.net... >I ordered some BC557 from Conrad.nl. > Normally you can hardly red what is written on a transistor, > but in this case the label is silver painted masked, > and does not say 'BC557', but 'B557C': > ftp://panteltje.com/pub/strange_transistors/BC557_rebranded_img_1806.jpg > > Also it looks like the top has been grinded so as to remove any original > marking. > I scraped of some of the silver painted text, but I could find nothing > under it. > On one of these I thought I could make out the number '2' on the top, > but then there are people whio see the strangest things in random > patterns, > so I am not sure: > ftp://panteltje.com/pub/strange_transistors/BC557_top_img_1808.jpg > > Any body has any idea what the difference is between a BC557 and a C557B? > Or is it a BC557B? > Or just any thing painted with the required number? > > Other transistors (BC547) look totally normal from Conrad. > I got a bit supicious when one of these did not work as expected, > measured the beta, about 330 at low currents, but seems to drop to much > lower at 100 mA. That says to me it's a jap' version and the full part should be 2SB557C. The Japs always leave off the 2S on small parts. |