Transistor Identity ?

A

Arfa Daily

Guest
Anyone come across a transistor "D 8050" ? The logo is just a small star.
That is followed by a "D", then below that "8050". My first thought was 2S -
D8050, but that turns up no data, except the usual component search engine
dead ends and non-existent data sheets. It's a standard TO92 D-line plastic
package, and the board has its pins marked as E-B-C. There is another
transistor of the same type on the board, and it reads as a conventional NPN
small signal transistor, so shouldn't be a problem to substitute. It would
just be nice to know what its ratings are.

In case it helps, its in the SMPS of a Wharfedale monitor speaker. It is in
the supply circuitry of the controller IC. The PSU is working ok - almost.
It had suffered a burn-up around the leg of a cap strapped across the
switching transformer somewhere. The resulting carbonised board had tracked
across to another print track, and taken that out, along with a zener that
was connected to that track. When the burn-up and tracking was all sorted,
the PSU came up ok, and all seemed to be well until it was connected to the
amplifier. With no signal, you could hear the woofer bumping quite fast.
Like quiet motorboating. If you 'scoped the rails, you could see them all
'bouncing' a couple of volts. Turns out that the control IC is starting and
stopping in bursts. It looks as though the startup supply is getting the IC
going, but the sustain supplsy from the switching transformer is not then
taking over. The bad transistor appears to be part of the regulator for this
supply. The zener that had blown was connected directly to the base of this
transistor, so it all seems to fit. If nobody knows any different, I think I
will try an MPSA42 in there. They have a good voltage and current rating,
and the right pinout.

Arfa
 
What a bizzarre situation. It looks like it's an American number !

2N8050 :

http://www.ebay.com/itm/20pcs-Transistor-2N8050-C8050-General-Purpose-TO-92-/130287351395

Whoda thunkit ?

T
 
On 22.06.2012 02:48, Arfa Daily wrote:
Anyone come across a transistor "D 8050" ? The logo is just a small
star. That is followed by a "D", then below that "8050". My first
thought was 2S - D8050, but that turns up no data, except the usual
component search engine dead ends and non-existent data sheets. It's a
standard TO92 D-line plastic package, and the board has its pins marked
as E-B-C.
Click to expand...
When I see the number 8050 on a TO92 package, my first guess is an
S8050: <http://www.alldatasheet.com/view.jsp?Searchword=S8050>

Best regards

Piotr
 
On Jun 21, 5:48 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
Anyone come across a transistor "D 8050" ?  The logo is just a small star.
That is followed by a "D", then below that "8050". My first thought was 2S -
D8050, but that turns up no data, except the usual component search engine
dead ends and non-existent data sheets. It's a standard TO92  D-line plastic
package, and the board has its pins marked as E-B-C.
Click to expand...
I've never seen such a logo and it's driving me crazy. Can you put it
on tinypic?

I keep thinking it must indicate the transistor is kosher (Dairy):

http://www.jewishceliacs.com/jcn%20graphics/Star-d.gif

In case it helps, its in the SMPS of a Wharfedale monitor speaker.
Click to expand...
How old is this? Current production, ten years old, twenty, more?
 
"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:fhPEr.207954$2l2.6475@fx01.am4...
Anyone come across a transistor "D 8050" ? The logo is just a small star.
That is followed by a "D", then below that "8050". My
Click to expand...
Try searching "S8050" - its something along those lines.

http://www.alldatasheet.com/datasheet-pdf/pdf/33773/WINGS/S8050.html

The complement is 8550.

They're the power complementary pair sometimes found on the same board as
the 9014 series.

There's data sheets from various sources on my other PC so if you're still
stuck.
 
"spamtrap1888" <spamtrap1888@gmail.com> wrote in message
news:7ef6e7bd-dec4-43ad-8db7-d7f23f968d84@mi5g2000pbc.googlegroups.com...
On Jun 21, 5:48 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
Anyone come across a transistor "D 8050" ? The logo is just a small
star.
That is followed by a "D", then below that "8050". My first thought was
2S -
D8050, but that turns up no data, except the usual component search
engine
dead ends and non-existent data sheets. It's a standard TO92 D-line
plastic
package, and the board has its pins marked as E-B-C.

I've never seen such a logo and it's driving me crazy. Can you put it
on tinypic?

I keep thinking it must indicate the transistor is kosher (Dairy):

http://www.jewishceliacs.com/jcn%20graphics/Star-d.gif


In case it helps, its in the SMPS of a Wharfedale monitor speaker.

How old is this? Current production, ten years old, twenty, more?
Click to expand...
Can't say that I'd ever seen it before, either, and I've been in this game a
long time. As to the item in question, I believe that it is at least recent
if not current. I seem to think that the shop owner that sent it to me for
repair, said that the owner had not had it all that long.

You should be able to see a picture of the transistor here

http://i48.tinypic.com/27wzj85.jpg

if I've got the address linking right.

Arfa
 
"Piotr Piatek" <piotr433@pisi.com.pl> wrote in message
news:a4icurFibsU1@mid.individual.net...
On 22.06.2012 02:48, Arfa Daily wrote:
Anyone come across a transistor "D 8050" ? The logo is just a small
star. That is followed by a "D", then below that "8050". My first
thought was 2S - D8050, but that turns up no data, except the usual
component search engine dead ends and non-existent data sheets. It's a
standard TO92 D-line plastic package, and the board has its pins marked
as E-B-C.

When I see the number 8050 on a TO92 package, my first guess is an S8050:
http://www.alldatasheet.com/view.jsp?Searchword=S8050

Best regards

Piotr
Click to expand...
Ah, yes ! Good call. With the "D" in front of the number, I hadn't even
considered that it could be an "S" prefix device, but you are right of
course. Four digit numbers in the '8000' range often are correctly prefixed
by "S". Maybe the "D" is actually part of the logo ?? I've put a piccy on
TinyPic - see my reply to spamtrap1888 for the link.

Having looked at the S8050 data, it looked a reasonable assumption that that
was indeed the type, so I put in a trusty MPSA42, which has the same pinout,
similar current rating and better voltage rating, and away it went. Control
IC then produced steady and continuous gate drive for the switching FETs,
which then produced correct and steady secondary-side voltages, so a good
result all round, and Christ knows, I needed one of those for a Friday,
after the crap week I've had ... :)

Arfa
 
On Jun 22, 5:45 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
"spamtrap1888" <spamtrap1...@gmail.com> wrote in message

news:7ef6e7bd-dec4-43ad-8db7-d7f23f968d84@mi5g2000pbc.googlegroups.com...









On Jun 21, 5:48 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
Anyone come across a transistor "D 8050" ?  The logo is just a small
star.
That is followed by a "D", then below that "8050". My first thought was
2S -
D8050, but that turns up no data, except the usual component search
engine
dead ends and non-existent data sheets. It's a standard TO92  D-line
plastic
package, and the board has its pins marked as E-B-C.

I've never seen such a logo and it's driving me crazy. Can you put it
on tinypic?

I keep thinking it must indicate the transistor is kosher (Dairy):

http://www.jewishceliacs.com/jcn%20graphics/Star-d.gif

In case it helps, its in the SMPS of a Wharfedale monitor speaker.

How old is this? Current production, ten years old, twenty, more?

Can't say that I'd ever seen it before, either, and I've been in this game a
long time. As to the item in question, I believe that it is at least recent
if not current. I seem to think that the shop owner that sent it to me for
repair, said that the owner had not had it all that long.

You should be able to see a picture of the transistor here

http://i48.tinypic.com/27wzj85.jpg

if I've got the address linking right.
Click to expand...
Thank you. The star almost looks like it has a little "i" in its
middle. And the two bottom points might be legs.

I think the D is placed where it is to make it clear it's not part of
the logo, i.e. as far away as possible. (Could it somehow be a date
code?) The absence of data books is quite annoying -- who would have
thought that the Internet would omit this transistor logo from its
collection of dull factoids.
 
"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:gu8Fr.226152$B64.130558@fx26.am4...
"Piotr Piatek" <piotr433@pisi.com.pl> wrote in message
news:a4icurFibsU1@mid.individual.net...
On 22.06.2012 02:48, Arfa Daily wrote:
Anyone come across a transistor "D 8050" ? The logo is just a small
star. That is followed by a "D", then below that "8050". My first
thought was 2S - D8050, but that turns up no data, except the usual
component search engine dead ends and non-existent data sheets. It's a
standard TO92 D-line plastic package, and the board has its pins marked
as E-B-C.

When I see the number 8050 on a TO92 package, my first guess is an S8050:
http://www.alldatasheet.com/view.jsp?Searchword=S8050

Best regards

Piotr



Ah, yes ! Good call. With the "D" in front of the number, I hadn't even
considered that it could be an "S" prefix device, but you are right of
course. Four digit numbers in the '8000' range often are correctly
prefixed by "S". Maybe the "D" is actually part of the logo ?? I've put a
piccy on TinyPic - see my reply to spamtrap1888 for the link.
Click to expand...
A single 'S' prefix is probably the most common, MPS is used by NS & various
others and fairchild use 'SS' prefix.
 
responding to
http://www.electrondepot.com/repair/transistor-identity-140609-.htm , Me, who
knows about valves too. wrote:
> arfa.daily At whites, a MFR of metal detectors 8050's were bought in bulk
stuck into an automated tester.
A bin lamp lit that you through it into. They were an un-classified very
inexpensive if 1 amp+ 200MHz part.
Your part had this tested, labeled and is a letter of the alphabet instead of
"b" plus a 2 digit number.
I have LB's of MPSA 5550's and 5123's with gold leads, having betas over 1100.
They made crappy three pole oscillators but great touch pad amps for Moog's.
 
On Friday, June 22, 2012 at 8:55:37 PM UTC-4, Arfa Daily wrote:
"Piotr Piatek" <piotr433@pisi.com.pl> wrote in message
news:a4icurFibsU1@mid.individual.net...
On 22.06.2012 02:48, Arfa Daily wrote:
Anyone come across a transistor "D 8050" ? The logo is just a small
star. That is followed by a "D", then below that "8050". My first
thought was 2S - D8050, but that turns up no data, except the usual
component search engine dead ends and non-existent data sheets. It's a
standard TO92 D-line plastic package, and the board has its pins marked
as E-B-C.

When I see the number 8050 on a TO92 package, my first guess is an S8050:
http://www.alldatasheet.com/view.jsp?Searchword=S8050

Best regards

Piotr



Ah, yes ! Good call. With the "D" in front of the number, I hadn't even
considered that it could be an "S" prefix device, but you are right of
course. Four digit numbers in the '8000' range often are correctly prefixed
by "S". Maybe the "D" is actually part of the logo ?? I've put a piccy on
TinyPic - see my reply to spamtrap1888 for the link.

Having looked at the S8050 data, it looked a reasonable assumption that that
was indeed the type, so I put in a trusty MPSA42, which has the same pinout,
similar current rating and better voltage rating, and away it went. Control
IC then produced steady and continuous gate drive for the switching FETs,
which then produced correct and steady secondary-side voltages, so a good
result all round, and Christ knows, I needed one of those for a Friday,
after the crap week I've had ... :)

Arfa
Click to expand...


Except that the S8050 is a PNP and you said that yours checks out as an NPN (and you installed an NPN which works), so any data on that S8050 won't help identifying your part. I'd keep my eye on it a few days before shipping it.
 
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