Rebranded transistors?
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From: Robert Baer on 19 Feb 2010 03:35 Jan Panteltje wrote: > 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. "Rebranding" (usually surplus or scrap) of all kinds of common parts has been going on for ages (at least 20 years).
From: Jan Panteltje on 19 Feb 2010 06:14 On a sunny day (Fri, 19 Feb 2010 12:03:00 +1100) it happened "Phil Allison" <phil_a(a)tpg.com.au> wrote in <7u66aeFa4uU1(a)mid.individual.net>: > >"Jan Panteltje" >> >> 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 > > >** It clearly says " C557B" > > The "C" very likely stands for Conrad. > > Makers will apply any number the buyer asks for. > > > >.... Phil Not that I want to trigger one of your rants, but other's posters sort of contradict the 'C' for Conrad :-)
From: Piotr Piatek on 19 Feb 2010 08:03 On Thu, 18 Feb 2010 14:52:25 GMT, Jan Panteltje wrote: >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': Please see the PDF document from this location: http://www.alldatasheet.com/datasheet-pdf/pdf/156354/PHILIPS/BC547.html Quoted from the table on page 3: Type number: BC547C Marking code: C547C Also an additional information: W: made in China Hopefully this will clear your doubts. Piotr
From: Jan Panteltje on 19 Feb 2010 09:08 On a sunny day (Fri, 19 Feb 2010 14:03:52 +0100) it happened Piotr Piatek <piotr433(a)pisi.com.pl> wrote in <hlm2t2$abq$1(a)nemesis.news.neostrada.pl>: > >On Thu, 18 Feb 2010 14:52:25 GMT, Jan Panteltje wrote: > >>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': > >Please see the PDF document from this location: >http://www.alldatasheet.com/datasheet-pdf/pdf/156354/PHILIPS/BC547.html > >Quoted from the table on page 3: > >Type number: BC547C >Marking code: C547C > >Also an additional information: > >W: made in China > >Hopefully this will clear your doubts. > >Piotr Absolutely fantastic! Thank you very much! And only in China could they thave somebody spray-paint each transistor LOL. I suspected that much :-)
From: Michael A. Terrell on 19 Feb 2010 23:59
Joerg wrote: > > Jan Panteltje wrote: > > On a sunny day (Thu, 18 Feb 2010 21:16:06 +0530) it happened "pimpom" > > <pimpom(a)invalid.invalid> wrote in <hljnc5$5pm$1(a)news.albasani.net>: > > > > [...] > > >> The beta vs. Ic curve on Philips' datasheet for a typical BC557B > >> gives beta of ~320 at 1mA and ~170 at 100mA. I don't find this > >> surprising as 100mA _is_ the maximum continuous Ic rating, and > >> it's quite normal for Si transistors to show considerable drops > >> in beta as we approach max Ic. > > > > Yep, doesn't sound unusual. > > > Maybe these are genuine, but I would prefer a label like 'Philips' or 'Motorola' or whatever. > > Why hide the manufacturer? > > Or does 'W' stand for some company? > > > > Wilips? Wotorola? Uncle Wen's Wonder Works? At one time it was used by Workman Electronics for their replacement line of semiconductors at a time when dozens of small companies hoped to replace the Sylvania - ECG line as the top seller. -- Greed is the root of all eBay. |