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Default Incorrectly marked transistors?

OK, to follow up on the "wrong parts sent by Behringer" thread,

I recently bought some TIP35C transistors from Farnell UK. Just before I
fitted one to an amplifier I thought I'd just check the pinouts.
Good job I did because instead of BCE they measured BEC.

Anyway I tried to order a different manufacturers part from the Farnel
website but ended up with more of the Mospecs.


Here is the weird bit:
I have 4 Mospec TIP35C in font of me with exactly the same batch codes, they
are all identical and from the same source (Farnell)
3 of them meaure BEC, the fourth one measures the correct BCE pinout.
Measurement done numerous times on a Peak DCA50e component checker, and a
video made to send to Farnel who would not at first believe me.


How is this possible?



Cheers,


Gareth.


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On 14/01/2014 10:10, Gareth Magennis wrote:
OK, to follow up on the "wrong parts sent by Behringer" thread,

I recently bought some TIP35C transistors from Farnell UK. Just before I
fitted one to an amplifier I thought I'd just check the pinouts.
Good job I did because instead of BCE they measured BEC.

Anyway I tried to order a different manufacturers part from the Farnel
website but ended up with more of the Mospecs.


Here is the weird bit:
I have 4 Mospec TIP35C in font of me with exactly the same batch codes, they
are all identical and from the same source (Farnell)
3 of them meaure BEC, the fourth one measures the correct BCE pinout.
Measurement done numerous times on a Peak DCA50e component checker, and a
video made to send to Farnel who would not at first believe me.


How is this possible?



Cheers,


Gareth.



Even weirder I have some marked TIP35C, makers apparently MEV and ST,
check out as perhaps TIP36C, never used so no idea what the V/A ratings
are, came from Grandata . They were for background stock and when I went
to use one Grandata had gone bust.
I assume they must be a favorite for pirating. The labelling is not
obviously suspect, ie printing wipes off but "ST" ones are skew to the
body and MEV ones look more like paint than whatever usual marking
material is

(second attempt., ******* mozilla thunderbird)
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"Gareth Magennis"


I recently bought some TIP35C transistors from Farnell UK. Just before I
fitted one to an amplifier I thought I'd just check the pinouts.
Good job I did because instead of BCE they measured BEC.


** That is just not possible.

The middle leg is always the collector and metal tab used for heatsinking.

FFS - get an ohmmeter and verify that simple fact.

Seems your dopey microprocessor ( ie software) based POS has gone ape and
confused Collector with Emitter.



..... Phil





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"Phil Allison" wrote in message
...

"Gareth Magennis"


I recently bought some TIP35C transistors from Farnell UK. Just before I
fitted one to an amplifier I thought I'd just check the pinouts.
Good job I did because instead of BCE they measured BEC.


** That is just not possible.

The middle leg is always the collector and metal tab used for heatsinking.

FFS - get an ohmmeter and verify that simple fact.

Seems your dopey microprocessor ( ie software) based POS has gone ape and
confused Collector with Emitter.



.... Phil




I did suspect my dopey checker, but even with a fresh battery it ALWAYS
reads EXACTLY the same,

which is: 3 of them measure BEC with an Hfe of 5, the other one BCE with an
Hfe of 20.
(All tabs connect to centre pin)

The replacements I finally got from Farnell with a different batch code
measure an Hfe between 40 and 70.


I know Hfe is kind of meaningless on these types of checker voltages, but
was still wondering why the checker would give a different pinout result
rather than fail the device.

I suspect all 4 of the "old" transistors are faulty, but still doesn't
explain how these managed to be sold to me by Farnell, or even got off the
production line without being checked.


Cheers,


Gareth.


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"Gareth Magennis"
"Phil Allison"


I recently bought some TIP35C transistors from Farnell UK. Just before
I fitted one to an amplifier I thought I'd just check the pinouts.
Good job I did because instead of BCE they measured BEC.


** That is just not possible.

The middle leg is always the collector and metal tab used for
heatsinking.

FFS - get an ohmmeter and verify that simple fact.

Seems your dopey microprocessor ( ie software) based POS has gone ape and
confused Collector with Emitter.



I did suspect my dopey checker, but even with a fresh battery it ALWAYS
reads EXACTLY the same,



** ROTFL - since when is THAT any reason to trust it ?????

" It must be right cos it always tells the SAME lie "

Wot an idiot you are.


which is: 3 of them measure BEC with an Hfe of 5, the other one BCE with
an Hfe of 20.


** No fooling.

BJTs have very low Hfes if C and E are reversed.

Like 2 or 3 instead of 100 or 200.

They *also* show very low readings if the meter is no ****ing good.

See how that might be confusing ???


(All tabs connect to centre pin)



** Then there is simply **NO** problem with the devices.
-------------------------------------------------------------------

YOU are the problem with your dopey meter that is not able to tests power
BJTs properly.

FYI Try it with a TV horizontal output transistor like the BU208.


The replacements I finally got from Farnell with a different batch code
measure an Hfe between 40 and 70.



** Testing the Hfe of *power transistors* is a whole DIFFERENT ball game
to small signal devices.

That is why I designed a special device just for power devices - published
as a project in Electronics Australia magazine in May 1988.

Test are done at a constant Ic of 0.6 amps instead of some fixed and way too
small Ib.

Results are spot on and match maker's data which follow the same idea.

Works fine with TV horizontal output devices, power darlingtons and any BJT
rated for high power.



I know Hfe is kind of meaningless on these types of checker voltages, but
was still wondering why the checker would give a different pinout result
rather than fail the device.


** Cos it is using the wrong approach for power BJT devices.

I suspect all 4 of the "old" transistors are faulty,


** ********.

You have a ******ing useless** meter that only works with those examples of
power BJT devices that exceed maker's specs at the low end of the Ic v Hfe
range.

Take a LOOK at some ACTUAL power BJT data sheets some time !!!!!!!!!

Hfe is NOT a constant !!!!!!!!!!!!



..... Phil





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On 14/01/2014 10:28, N_Cook wrote:
On 14/01/2014 10:10, Gareth Magennis wrote:
OK, to follow up on the "wrong parts sent by Behringer" thread,

I recently bought some TIP35C transistors from Farnell UK. Just before I
fitted one to an amplifier I thought I'd just check the pinouts.
Good job I did because instead of BCE they measured BEC.

Anyway I tried to order a different manufacturers part from the Farnel
website but ended up with more of the Mospecs.


Here is the weird bit:
I have 4 Mospec TIP35C in font of me with exactly the same batch
codes, they
are all identical and from the same source (Farnell)
3 of them meaure BEC, the fourth one measures the correct BCE pinout.
Measurement done numerous times on a Peak DCA50e component checker, and a
video made to send to Farnel who would not at first believe me.


How is this possible?



Cheers,


Gareth.



Even weirder I have some marked TIP35C, makers apparently MEV and ST,
check out as perhaps TIP36C, never used so no idea what the V/A ratings
are, came from Grandata . They were for background stock and when I went
to use one Grandata had gone bust.
I assume they must be a favorite for pirating. The labelling is not
obviously suspect, ie printing wipes off but "ST" ones are skew to the
body and MEV ones look more like paint than whatever usual marking
material is

(second attempt., ******* mozilla thunderbird)


closer looking at them . The bodies of "MEV" and "ST" are exactly the
same in minute detail, highly unlikely for different makers.
Guillotine imperfections in the heatsink stampings appear in exactly the
same place, the blow-hole? dimples in the encapsulation have the same
shiney appearance and matt for the rest of the body , two recesses each
side of the body show .5mm of the underlying heatsink, 2 tiny overspill
encapsulant splurges over the tab are the same etc
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"Phil Allison" wrote in message
...

"Gareth Magennis"
"Phil Allison"


I recently bought some TIP35C transistors from Farnell UK. Just before
I fitted one to an amplifier I thought I'd just check the pinouts.
Good job I did because instead of BCE they measured BEC.


** That is just not possible.

The middle leg is always the collector and metal tab used for
heatsinking.

FFS - get an ohmmeter and verify that simple fact.

Seems your dopey microprocessor ( ie software) based POS has gone ape
and confused Collector with Emitter.



I did suspect my dopey checker, but even with a fresh battery it ALWAYS
reads EXACTLY the same,



** ROTFL - since when is THAT any reason to trust it ?????

" It must be right cos it always tells the SAME lie "

Wot an idiot you are.


which is: 3 of them measure BEC with an Hfe of 5, the other one BCE with
an Hfe of 20.


** No fooling.

BJTs have very low Hfes if C and E are reversed.

Like 2 or 3 instead of 100 or 200.

They *also* show very low readings if the meter is no ****ing good.

See how that might be confusing ???


(All tabs connect to centre pin)



** Then there is simply **NO** problem with the devices.
-------------------------------------------------------------------

YOU are the problem with your dopey meter that is not able to tests power
BJTs properly.

FYI Try it with a TV horizontal output transistor like the BU208.


The replacements I finally got from Farnell with a different batch code
measure an Hfe between 40 and 70.



** Testing the Hfe of *power transistors* is a whole DIFFERENT ball game
to small signal devices.

That is why I designed a special device just for power devices -
published as a project in Electronics Australia magazine in May 1988.

Test are done at a constant Ic of 0.6 amps instead of some fixed and way
too small Ib.

Results are spot on and match maker's data which follow the same idea.

Works fine with TV horizontal output devices, power darlingtons and any
BJT rated for high power.



I know Hfe is kind of meaningless on these types of checker voltages, but
was still wondering why the checker would give a different pinout result
rather than fail the device.


** Cos it is using the wrong approach for power BJT devices.

I suspect all 4 of the "old" transistors are faulty,


** ********.

You have a ******ing useless** meter that only works with those examples
of power BJT devices that exceed maker's specs at the low end of the Ic v
Hfe range.

Take a LOOK at some ACTUAL power BJT data sheets some time !!!!!!!!!

Hfe is NOT a constant !!!!!!!!!!!!



.... Phil





Yes I know Hfe is not constant, that is why I said the reading is
meaningless on such a low voltage checker.

I do not use this device to measure Hfe, I don't usually give a **** what
the Hfe of a transistor is, I assume all new ones I buy from Farnell are
within manufacturers spec.
I usually just want to know if a transistor is bad, what pinout it is, and
whether or not it tests on this meter in the same ballpark as a known good
one.

These 4 "faulty" transistors do NOT test in the same ballpark, they probably
DO exceed the maker's spec if they work properly at all. In that respect
the tester has done all I have asked of it.

I am not going to put one of these devices into a Power Amp (which I was
about to do before I tested them) and have it blow up in my face. Farnell
can damn well send me 4 good transistors which ARE in the right ballpark,
which is exactly what they have done, one of which went into the Power Amp
which did not blow up in my face.



Cheers,


Gareth.


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How about phony products from China?

You should bring this to Farnell's attention.
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"Phil Allison" wrote in message ...

You have a ******ing useless** meter that only works with those
examples of power BJT devices that exceed maker's specs at the
low end of the Ic v Hfe range.


Amazing. How does one design such a clever product?
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"William Sommerwerck"


** **** OFF MORONIC TROLL







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Phil, we've (or at least I've) been putting up with your crap for a long time.

When are you going to get professional help?
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On 14/01/2014 10:28, N_Cook wrote:
ie printing wipes off


should be
ie printing does not wipe off, like that chalky script on valves
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Phil Allison wrote:

"Gareth Magennis"


I recently bought some TIP35C transistors from Farnell UK. Just before I
fitted one to an amplifier I thought I'd just check the pinouts.
Good job I did because instead of BCE they measured BEC.


** That is just not possible.

The middle leg is always the collector and metal tab used for heatsinking.

FFS - get an ohmmeter and verify that simple fact.

Seems your dopey microprocessor ( ie software) based POS has gone ape and
confused Collector with Emitter.


Agreed.

those component testers are sketchy in that you have no idea what they are
doing or how they draw conclusions.


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"Cydrome Leader"
Phil Allison
"Gareth Magennis"



I recently bought some TIP35C transistors from Farnell UK. Just before
I
fitted one to an amplifier I thought I'd just check the pinouts.
Good job I did because instead of BCE they measured BEC.


** That is just not possible.

The middle leg is always the collector and metal tab used for
heatsinking.

FFS - get an ohmmeter and verify that simple fact.

Seems your dopey microprocessor ( ie software) based POS has gone ape and
confused Collector with Emitter.


Agreed.

those component testers are sketchy in that you have no idea what they are
doing or how they draw conclusions.


** Exactly.

The tester that Gareth has operates at very low currents and voltages - a
couple of mA at most.

Some power BJTs lose all current gain at that level, showing Hfes of maybe 1
or 2.

Very likely, this is fooling his meter into giving wrong info about C and E
terminals - since the reading is like that when C and E are reversed.

The tester I designed operates from a 12V supply and one sets the base drive
current with a wirewound pot to get 0.5 amps from the supply.

A calibrated scale gave the base current as a ratio to that current - or
Hfe.

Small signal "Beta" testers are USELESS for this job.


..... Phil




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"William Sommerwerck"


** **** OFF MORONIC TROLL


"William Sommerwerck"


** **** OFF MORONIC TROLL


"William Sommerwerck"


** **** OFF MORONIC TROLL













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"Phil Allison" wrote in message ...

The tester that Gareth has operates at very low currents and
voltages - a couple of mA at most.
Some power BJTs lose all current gain at that level, showing
Hfes of maybe 1 or 2.
Very likely, this is fooling his meter into giving wrong info
about C and E terminals -- since the reading is like that when
C and E are reversed.


If that's true... Is there sufficient sample-sample variation for this to
occur?

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"Gareth Magennis"


** You are liar and a prize ****.

**** you.




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In article ,
says...

"Phil Allison" wrote in message
...

"Gareth Magennis"
"Phil Allison"


I recently bought some TIP35C transistors from Farnell UK. Just before
I fitted one to an amplifier I thought I'd just check the pinouts.
Good job I did because instead of BCE they measured BEC.


** That is just not possible.

The middle leg is always the collector and metal tab used for
heatsinking.

FFS - get an ohmmeter and verify that simple fact.

Seems your dopey microprocessor ( ie software) based POS has gone ape
and confused Collector with Emitter.



I did suspect my dopey checker, but even with a fresh battery it ALWAYS
reads EXACTLY the same,



** ROTFL - since when is THAT any reason to trust it ?????

" It must be right cos it always tells the SAME lie "

Wot an idiot you are.


which is: 3 of them measure BEC with an Hfe of 5, the other one BCE with
an Hfe of 20.


** No fooling.

BJTs have very low Hfes if C and E are reversed.

Like 2 or 3 instead of 100 or 200.

They *also* show very low readings if the meter is no ****ing good.

See how that might be confusing ???



you need a real full range tester..
I have an old B&K that has test currents to select from and you need
to use the upper scale to properly test large units.

Bigger units have higher saturation voltage, higher forward Vbe voltage
and requires more Ibe just to get out of the hole..

In otherwords, you need to subject it to higher currents.

There are a variety of power BJTs that have much different saturations
on the Vce(sat) verses the Vf(be) ect.

If you have one of those auto sensing units, it'll fail!

Jamie


Jamie

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"Gareth Magennis" wrote in message
...


"Phil Allison" wrote in message
...

"Gareth Magennis"
"Phil Allison"


I recently bought some TIP35C transistors from Farnell UK. Just before
I fitted one to an amplifier I thought I'd just check the pinouts.
Good job I did because instead of BCE they measured BEC.


** That is just not possible.

The middle leg is always the collector and metal tab used for
heatsinking.

FFS - get an ohmmeter and verify that simple fact.

Seems your dopey microprocessor ( ie software) based POS has gone ape
and confused Collector with Emitter.



I did suspect my dopey checker, but even with a fresh battery it ALWAYS
reads EXACTLY the same,



** ROTFL - since when is THAT any reason to trust it ?????

" It must be right cos it always tells the SAME lie "

Wot an idiot you are.


which is: 3 of them measure BEC with an Hfe of 5, the other one BCE with
an Hfe of 20.


** No fooling.

BJTs have very low Hfes if C and E are reversed.

Like 2 or 3 instead of 100 or 200.

They *also* show very low readings if the meter is no ****ing good.

See how that might be confusing ???


(All tabs connect to centre pin)



** Then there is simply **NO** problem with the devices.
-------------------------------------------------------------------

YOU are the problem with your dopey meter that is not able to tests power
BJTs properly.

FYI Try it with a TV horizontal output transistor like the BU208.


The replacements I finally got from Farnell with a different batch code
measure an Hfe between 40 and 70.



** Testing the Hfe of *power transistors* is a whole DIFFERENT ball game
to small signal devices.

That is why I designed a special device just for power devices -
published as a project in Electronics Australia magazine in May 1988.

Test are done at a constant Ic of 0.6 amps instead of some fixed and way
too small Ib.

Results are spot on and match maker's data which follow the same idea.

Works fine with TV horizontal output devices, power darlingtons and any
BJT rated for high power.



I know Hfe is kind of meaningless on these types of checker voltages, but
was still wondering why the checker would give a different pinout result
rather than fail the device.


** Cos it is using the wrong approach for power BJT devices.

I suspect all 4 of the "old" transistors are faulty,


** ********.

You have a ******ing useless** meter that only works with those examples
of power BJT devices that exceed maker's specs at the low end of the Ic v
Hfe range.

Take a LOOK at some ACTUAL power BJT data sheets some time !!!!!!!!!

Hfe is NOT a constant !!!!!!!!!!!!



.... Phil





Yes I know Hfe is not constant, that is why I said the reading is
meaningless on such a low voltage checker.

I do not use this device to measure Hfe, I don't usually give a **** what
the Hfe of a transistor is, I assume all new ones I buy from Farnell are
within manufacturers spec.
I usually just want to know if a transistor is bad, what pinout it is, and
whether or not it tests on this meter in the same ballpark as a known good
one.

These 4 "faulty" transistors do NOT test in the same ballpark, they probably
DO exceed the maker's spec if they work properly at all. In that respect
the tester has done all I have asked of it.

I am not going to put one of these devices into a Power Amp (which I was
about to do before I tested them) and have it blow up in my face. Farnell
can damn well send me 4 good transistors which ARE in the right ballpark,
which is exactly what they have done, one of which went into the Power Amp
which did not blow up in my face.



Cheers,


Gareth.


The first tests to do on a suspect Transistor is using the Diode test mode
on a DMM (assuming there are no cracks in its case or plastic blown off -
that lets out the magic smoke). Start testing across two leads at a time,
go forwards (the red lead on one pin and the black on another) then reverse
polarity (black to red). Try all three variations. On a good transistor you
should get about 0.6 volts across two sets of pins, one of them being common
between the two, that is the base lead. When you reverse the leads it should
read OL on your DMM. From there you can determine if it is NPN or PNP
transistor. If one reading shows about 1.2 Volts and OL in the reverse
direction, its a working darlington transistor. If you read a short or
readings in forwards and reverse, then the transistor is NFG. Google the
part number, it is very easy - You will find pin outs, datasheets on almost
anything.

Shaun



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On 14/01/2014 23:55, Gareth Magennis wrote:
"Phil Allison" wrote in message
...

"Gareth Magennis"
"Phil Allison"


I recently bought some TIP35C transistors from Farnell UK. Just before
I fitted one to an amplifier I thought I'd just check the pinouts.
Good job I did because instead of BCE they measured BEC.


** That is just not possible.

The middle leg is always the collector and metal tab used for
heatsinking.

FFS - get an ohmmeter and verify that simple fact.

Seems your dopey microprocessor ( ie software) based POS has gone ape
and confused Collector with Emitter.



I did suspect my dopey checker, but even with a fresh battery it ALWAYS
reads EXACTLY the same,



** ROTFL - since when is THAT any reason to trust it ?????

" It must be right cos it always tells the SAME lie "

Wot an idiot you are.


which is: 3 of them measure BEC with an Hfe of 5, the other one BCE with
an Hfe of 20.


** No fooling.

BJTs have very low Hfes if C and E are reversed.

Like 2 or 3 instead of 100 or 200.

They *also* show very low readings if the meter is no ****ing good.

See how that might be confusing ???


(All tabs connect to centre pin)



** Then there is simply **NO** problem with the devices.
-------------------------------------------------------------------

YOU are the problem with your dopey meter that is not able to tests power
BJTs properly.

FYI Try it with a TV horizontal output transistor like the BU208.


The replacements I finally got from Farnell with a different batch code
measure an Hfe between 40 and 70.



** Testing the Hfe of *power transistors* is a whole DIFFERENT ball game
to small signal devices.

That is why I designed a special device just for power devices -
published as a project in Electronics Australia magazine in May 1988.

Test are done at a constant Ic of 0.6 amps instead of some fixed and way
too small Ib.

Results are spot on and match maker's data which follow the same idea.

Works fine with TV horizontal output devices, power darlingtons and any
BJT rated for high power.



I know Hfe is kind of meaningless on these types of checker voltages, but
was still wondering why the checker would give a different pinout result
rather than fail the device.


** Cos it is using the wrong approach for power BJT devices.

I suspect all 4 of the "old" transistors are faulty,


** ********.

You have a ******ing useless** meter that only works with those examples
of power BJT devices that exceed maker's specs at the low end of the Ic v
Hfe range.

Take a LOOK at some ACTUAL power BJT data sheets some time !!!!!!!!!

Hfe is NOT a constant !!!!!!!!!!!!



.... Phil





Yes I know Hfe is not constant, that is why I said the reading is
meaningless on such a low voltage checker.

I do not use this device to measure Hfe, I don't usually give a **** what
the Hfe of a transistor is, I assume all new ones I buy from Farnell are
within manufacturers spec.
I usually just want to know if a transistor is bad, what pinout it is, and
whether or not it tests on this meter in the same ballpark as a known good
one.

These 4 "faulty" transistors do NOT test in the same ballpark, they probably
DO exceed the maker's spec if they work properly at all. In that respect
the tester has done all I have asked of it.

I am not going to put one of these devices into a Power Amp (which I was
about to do before I tested them) and have it blow up in my face. Farnell
can damn well send me 4 good transistors which ARE in the right ballpark,
which is exactly what they have done, one of which went into the Power Amp
which did not blow up in my face.



Cheers,


Gareth.



Some transistors work surprisingly well upside-down. Not well enough to
rely upon, but well enough to confuse people.

Why don't you measure the breakdown voltage when you reverse-bias the
base-emitter junction and then do the same with the base-collector junction.

One of these junctions will break down at a few volts, that will be the
one with the emitter. The other one will break down at some higher
voltage and will be the collector.

This test is slightly destructive in that it can permanently worsen the
noise figure (and probably other parameters) of low-noise small-signal
transistors, especially if you don't limit the current to a very small
value, but in this case I guess you don't want the suspect transistors
any more so you might as well do this test, and see whether your meter
is right or wrong.

Also, the tab is always the collector, unless the counterfeiters went to
extreme expense to re-package exotic RF devices as some bog standard
part and sell them for a huge loss, which is the reverse of the usual
business model. The bulk of the chip of silicon (the substrate) is the
collector, and this is stuck with conductive glue, or soldered, to the
tab. Therefore unless someone put a thermally-conducting,
electrically-insulating layer in between the chip and the tab, (which is
expensive and uncommon), the tab is the collector. This applies to both
NPN and PNP transistors.

It is easy to believe that measuring instruments with a digital display
are always right but sometimes they aren't.

Chris


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Default Incorrectly marked transistors?



"William Sommerwerck" wrote in message
...
How about phony products from China?

You should bring this to Farnell's attention.


I used to trust Farnell absolutely, but recently, I've had cause on several
occasions to be suspicious of the pedigree of some semiconductors that
they've supplied me. There seems to have been a subtle shift in their
business model from 'Lets be helpful and honest to our customers, and make
some money along the way' to 'Let's make some money ...'

Arfa

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Default Totally Spurious Complaint


"Chris Jones"

It is easy to believe that measuring instruments with a digital display
are always right but sometimes they aren't.


** I have a few TIP35Cs in stock - Motorola and ST brands.

Connected with C and E reversed, the ST brand ones show Hfes of 20 and 26.

With correct connection, the Hfe is over 200.

This is with an Ic of 0.5 amp.

Any BJT should show a much higher Hfe with C and E used the normal way -
long as Ic is within the maker's specs.

Which does not include 2mA for a 25amp BJT.


.... Phil




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Default Different story now


"Gareth Magennis"


With regards me testing these TIP's with my dodgy tester, I may well be
wrong about them being dodgy, I understand fully what Phil has been
saying, and it is entirely possible he has been correct all along. Thing
is I reacted to the way he was reacting, maybe that wasn't the smartest
thing to do, I can normally tolerate him a lot better.
I apologise for that, Phil, it shouldn't really have gone that way.



** OK.

I stated from the very outset that I knew a Hfe reading from this tester
on a Power Transistor was "meaningless", but this seems to have been
largely ignored.


** As I explained repeatedly, the Peak meter uses Hfe readings to determine
C and E.

So if it *cannot read Hfe reliably* for a particular BJT - then it CANNOT
always get C and E right.

There is no magic way to determine C and E with certainty other than break
down voltage tests ( the CE junction should go at about 12V while the CB
one ought to be higher) - with only an internal 5V supply, the Peak tester
cannot do this test.



In fact the reason I knew of this was because of previous posts by Phil
probably a couple of years ago now on this thread.

Thing is though, all 4 replacements read OK at a healthy Hfe of 60 - 70,
where all 4 of the other batch read pretty much zero, most probably
because of a confused pinout diagnosis from the tester, or maybe because
they really are dodgy at the lower extremities of operation, where they
would not be operated anyway.

I did later construct a quick test rig on 2 of these old "dodgy" TIP35C's
which showed, at around 0.5A collector current, an Hfe of around 49, and
the correct pinout.



** Halleluiah.


..... Phil




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