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Incorrectly marked transistors?
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Gareth Magennis
Jan 14, 2014, 5:10:13 AM1/14/14
to
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.
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.
N_Cook
Jan 14, 2014, 5:28:19 AM1/14/14
to
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., bastard mozilla thunderbird)
Phil Allison
Jan 14, 2014, 5:39:31 AM1/14/14
to
"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.
>
> 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.
>
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
Gareth Magennis
Jan 14, 2014, 5:56:18 AM1/14/14
to
"Phil Allison" <phi...@tpg.com.au> wrote in message
news:bjkido...@mid.individual.net...
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.
Phil Allison
Jan 14, 2014, 6:54:26 AM1/14/14
to
"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 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 ?????
> reads EXACTLY the same,
" 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.
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 fucking good.
See how that might be confusing ???
> (All tabs connect to centre pin)
-------------------------------------------------------------------
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.
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.
> I suspect all 4 of the "old" transistors are faulty,
You have a **fucking 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
N_Cook
Jan 14, 2014, 7:29:31 AM1/14/14
to
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
Gareth Magennis
Jan 14, 2014, 7:55:34 AM1/14/14
to
news:bjkmq7...@mid.individual.net...
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 fuck 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.
meaningless on such a low voltage checker.
I do not use this device to measure Hfe, I don't usually give a fuck 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.
William Sommerwerck
Jan 14, 2014, 7:59:08 AM1/14/14
to
How about phony products from China?
You should bring this to Farnell's attention.
You should bring this to Farnell's attention.
William Sommerwerck
Jan 14, 2014, 8:02:46 AM1/14/14
to
"Phil Allison" wrote in message news:bjkmq7...@mid.individual.net...
> You have a **fucking 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?
> You have a **fucking 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.
Phil Allison
Jan 14, 2014, 8:09:59 AM1/14/14
to
> 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,
** No, but the dopey fuckin meter IS doing just that.
> meaningless on such a low voltage checker.
>
> I do not use this device to measure Hfe,
How do you imagine it tells C from E ??
Might it not use the Hfe test to do it ???????????
-------------------------------------------------------
How would YOU tell C from E with no other data ?
> 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.
HOW MANY TIMES do you have to be FUCKING TOLD ???????
> These 4 "faulty" transistors ..
** FFS - YOU are the ONLY faulty thing !!!!!!!!!!
THAT STINKING POS CANNOT TEST POWER BJTs !!!!!!!
It is a SMALL SIGNAL device tester.
READ the fucking spec sheet for it - DICK HEAD !!
The throw that POS in the bin and DO the TEST ANOTHER WAY !!!!
Fuck you are DUMB !!!!!!!!!!
.... Phil
Phil Allison
Jan 14, 2014, 8:11:14 AM1/14/14
to
"William Sommerwerck"
** FUCK OFF MORONIC TROLL
Phil Allison
Jan 14, 2014, 8:12:17 AM1/14/14
to
"William Sommerwerck"
** FUCK OFF & DIE MORONIC TROLL !!
William Sommerwerck
Jan 14, 2014, 8:25:59 AM1/14/14
to
"Phil Allison" wrote in message news:bjkrc6...@mid.individual.net...
When are you going to wake up and get professional help?
When are you going to wake up and get professional help?
William Sommerwerck
Jan 14, 2014, 8:28:20 AM1/14/14
to
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?
When are you going to get professional help?
N_Cook
Jan 14, 2014, 11:15:59 AM1/14/14
to
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
Cydrome Leader
Jan 14, 2014, 1:54:23 PM1/14/14
to
those component testers are sketchy in that you have no idea what they are
doing or how they draw conclusions.
Uffe Bærentsen
Jan 14, 2014, 6:39:52 PM1/14/14
to
Den 14-01-2014 14:09, Phil Allison skrev:
Hi Phil
Interesting to read this:
>>> ** 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.
Is there any chance that you would have an electronic copy of this that
you would be willing to share?
Since I'm in Denmark which happens to be on the other side of the planet
compared to Australia, magazines from Australia are kind of rare around here
For reply please remove this from my mail adr: _FJERNES_ (the
underscores need to be removed as well).
--
Uffe
Hi Phil
Interesting to read this:
>>> ** 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.
you would be willing to share?
Since I'm in Denmark which happens to be on the other side of the planet
compared to Australia, magazines from Australia are kind of rare around here
For reply please remove this from my mail adr: _FJERNES_ (the
underscores need to be removed as well).
--
Uffe
Gareth Magennis
Jan 14, 2014, 7:13:00 PM1/14/14
to
"Phil Allison" wrote in message news:bjkr7s...@mid.individual.net...
I know when I come across an anomaly. That comes with an intimate knowledge
of how your test equipment works.
Gareth.
Phil Allison
Jan 14, 2014, 7:31:08 PM1/14/14
to
"Gareth Magennis"
> Phil. I know how my test equipment works,
And you have NO FUCKING IDEA how to test a power BJT.
> I know when I come across an anomaly.
FYI: Do you have two DC power supplies?
Use one to provide a collector current of say 0.5 amps.
Use the other to drive the base via a 1 kohm resistor so Ic is 0.5 amps.
The ratio of currents will give you the correct Hfe for most power BJT
devices.
.... Phil
Phil Allison
Jan 14, 2014, 7:46:18 PM1/14/14
to
"Cydrome Leader"
> Phil Allison
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
Phil Allison
Jan 14, 2014, 7:46:42 PM1/14/14
to
Phil Allison
Jan 14, 2014, 7:46:59 PM1/14/14
to
"William Sommerwerck"
** FUCK OFF MORONIC TROLL
"William Sommerwerck"
** FUCK OFF MORONIC TROLL
"William Sommerwerck"
** FUCK OFF MORONIC TROLL
"William Sommerwerck"
** FUCK OFF MORONIC TROLL
"William Sommerwerck"
** FUCK OFF MORONIC TROLL
** FUCK OFF MORONIC TROLL
"William Sommerwerck"
** FUCK OFF MORONIC TROLL
"William Sommerwerck"
** FUCK OFF MORONIC TROLL
"William Sommerwerck"
** FUCK OFF MORONIC TROLL
"William Sommerwerck"
** FUCK OFF MORONIC TROLL
Gareth Magennis
Jan 14, 2014, 7:51:33 PM1/14/14
to
"Phil Allison" wrote in message news:bjm352...@mid.individual.net...
transistor.
All I need to know is if it works within design parameters, or it doesn't.
If it doesn't I will replace it with something that does.
I will leave Farnell to ensure that the Hfe of the replacement device is
what it should be. That is what I am paying them for.
Otherwise I would have to charge my clients double the labour charge to
verify such things, and they would not be happy, and I would be out of
business very quickly.
Cheers,
Gareth.
Gareth Magennis
Jan 14, 2014, 8:07:06 PM1/14/14
to
Phil, I am not at all interested in finding the accurate Hfe of a
transistor.
All I need to know is if it works within design parameters, or it doesn't.
If it doesn't I will replace it with something that does.
I will leave Farnell to ensure that the Hfe of the replacement device is
what it should be. That is what I am paying them for.
Otherwise I would have to charge my clients double the labour charge to
verify such things, and they would not be happy, and I would be out of
business very quickly.
Cheers,
Gareth.
faulty parts and me identifying them with a Mickey Mouse component tester.
Allegedly.
Cheers,
Gareth.
Cydrome Leader
Jan 14, 2014, 8:42:35 PM1/14/14
to
Gareth Magennis <gareth....@ntlworld.com> wrote:
>
>
> "Phil Allison" wrote in message news:bjm352...@mid.individual.net...
>
>
> "Gareth Magennis"
>
>
>> Phil. I know how my test equipment works,
>
> ** Like hell you do !!!!!!!!!!
>
> And you have NO FUCKING IDEA how to test a power BJT.
>
>
>> I know when I come across an anomaly.
>
> ** You think the sky is falling and run around like a headless chook.
>
>
>
> FYI: Do you have two DC power supplies?
>
> Use one to provide a collector current of say 0.5 amps.
>
> Use the other to drive the base via a 1 kohm resistor so Ic is 0.5 amps.
>
> The ratio of currents will give you the correct Hfe for most power BJT
> devices.
>
>
>
> .... Phil
>
>
>
>
> Phil, I am not at all interested in finding the accurate Hfe of a
> transistor.
> All I need to know is if it works within design parameters, or it doesn't.
Are you confident your tester is performing tests within operating
>
>
> "Phil Allison" wrote in message news:bjm352...@mid.individual.net...
>
>
> "Gareth Magennis"
>
>
>> Phil. I know how my test equipment works,
>
> ** Like hell you do !!!!!!!!!!
>
> And you have NO FUCKING IDEA how to test a power BJT.
>
>
>> I know when I come across an anomaly.
>
> ** You think the sky is falling and run around like a headless chook.
>
>
>
> FYI: Do you have two DC power supplies?
>
> Use one to provide a collector current of say 0.5 amps.
>
> Use the other to drive the base via a 1 kohm resistor so Ic is 0.5 amps.
>
> The ratio of currents will give you the correct Hfe for most power BJT
> devices.
>
>
>
> .... Phil
>
>
>
>
> Phil, I am not at all interested in finding the accurate Hfe of a
> transistor.
> All I need to know is if it works within design parameters, or it doesn't.
parameters of your device under test?
Phil Allison
Jan 14, 2014, 8:46:37 PM1/14/14
to
"Gareth Magennis"
> "Phil Allison" "Gareth Magennis"
>
>
>> Phil. I know how my test equipment works,
>
> ** Like hell you do !!!!!!!!!!
>
> And you have NO FUCKING IDEA how to test a power BJT.
>
>
>> I know when I come across an anomaly.
>
> ** You think the sky is falling and run around like a headless chook.
>
>
>
> FYI: Do you have two DC power supplies?
>
> Use one to provide a collector current of say 0.5 amps.
>
> Use the other to drive the base via a 1 kohm resistor so Ic is 0.5 amps.
>
> The ratio of currents will give you the correct Hfe for most power BJT
> devices.
>
>
>
>
>> Phil. I know how my test equipment works,
>
> ** Like hell you do !!!!!!!!!!
>
> And you have NO FUCKING IDEA how to test a power BJT.
>
>
>> I know when I come across an anomaly.
>
> ** You think the sky is falling and run around like a headless chook.
>
>
>
> FYI: Do you have two DC power supplies?
>
> Use one to provide a collector current of say 0.5 amps.
>
> Use the other to drive the base via a 1 kohm resistor so Ic is 0.5 amps.
>
> The ratio of currents will give you the correct Hfe for most power BJT
> devices.
>
>
>
> Phil, I am not at all interested in finding the accurate Hfe of a
> transistor.
>
> All I need to know is if it works within design parameters, or it doesn't.
** Then put some in an ampifier and see.
> transistor.
>
> All I need to know is if it works within design parameters, or it doesn't.
> I will leave Farnell to ensure that the Hfe of the replacement device...
** HUH ???
You are one arrogant pommy pig.
You have NOTHING to say there is ANY problem with the TIP35/36s you
were supplied.
You come here asking for advice - then you COMPLETELY IGNORE IT.
YOU need a fucking good kick RIGHT UP THE ARSE.
Fucking IDIOT.
.... Phil
Phil Allison
Jan 14, 2014, 8:48:35 PM1/14/14
to
"Gareth Magennis"
>
>
> Phil, I am not at all interested in finding the accurate Hfe of a
> transistor.
> All I need to know is if it works within design parameters, or it doesn't.
>
> If it doesn't I will replace it with something that does.
>
> I will leave Farnell to ensure that the Hfe of the replacement device is
> what it should be. That is what I am paying them for.
> Otherwise I would have to charge my clients double the labour charge to
> verify such things, and they would not be happy, and I would be out of
> business very quickly.
>
> Phil, I am not at all interested in finding the accurate Hfe of a
> transistor.
> All I need to know is if it works within design parameters, or it doesn't.
>
> If it doesn't I will replace it with something that does.
>
> I will leave Farnell to ensure that the Hfe of the replacement device is
> what it should be. That is what I am paying them for.
> Otherwise I would have to charge my clients double the labour charge to
> verify such things, and they would not be happy, and I would be out of
> business very quickly.
** HUH ???
You are one arrogant pommy pig.
You have NOTHING to say there is ANY problem with the TIP35/36s you
were supplied.
You came here asking for advice - then you COMPLETELY IGNORE IT.
You are one arrogant pommy pig.
You have NOTHING to say there is ANY problem with the TIP35/36s you
were supplied.
William Sommerwerck
Jan 14, 2014, 9:07:31 PM1/14/14
to
"Gareth Magennis" wrote in message news:%alBu.3143$5p6....@fx25.am4...
> Hmm, having said that, the whole thread is really about
> Farnell supplying faulty parts and me identifying them
> with a Mickey Mouse component tester.
Correct. Please let us know if they turn out to be counterfeit.
> Hmm, having said that, the whole thread is really about
> Farnell supplying faulty parts and me identifying them
> with a Mickey Mouse component tester.
William Sommerwerck
Jan 14, 2014, 9:08:46 PM1/14/14
to
"Phil Allison" wrote in message news:bjm42p...@mid.individual.net...
You should consider having a rubber stamp made. Preferably the self-inking
kind.
kind.
Gareth Magennis
Jan 14, 2014, 9:11:02 PM1/14/14
to
"Cydrome Leader" wrote in message news:lb4p2b$7fn$1...@reader1.panix.com...
not produce higher test voltages.
That is not the point.
The point is I can do a direct A/B comparison between devices I know work
and the one in question.
If after years of doing this I come across a batch of transistors that seem
to defy all logic, then I will suspect those transistors as being faulty or
out of spec.
And, if those transistors are then replaced with a different batch from the
same manufacturer and they all test as OK, then my suspicions are confirmed.
This is not rocket science, it is just logic.
Cheers,
Gareth.
William Sommerwerck
Jan 14, 2014, 9:11:07 PM1/14/14
to
"Phil Allison" wrote in message news:bjm41j...@mid.individual.net...
> 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
occur?
> 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
> C and E are reversed.
If that's true... Is there sufficient sample-sample variation for this to
occur?
Gareth Magennis
Jan 14, 2014, 9:37:11 PM1/14/14
to
"Phil Allison" wrote in message news:bjm7m8...@mid.individual.net...
promote your Hfe tester design.
Of which I am not in the least bit interested.
Cheers,
Gareth.
Phil Allison
Jan 14, 2014, 10:07:29 PM1/14/14
to
"Gareth Magennis"
** You are liar and a prize cunt.
Fuck you.
Phil Allison
Jan 14, 2014, 10:10:52 PM1/14/14
to
"Gareth Magennis"
> This is not rocket science, it is just logic.
The " Peak DCA50e " is useless for testing power transistors.
And YOU are just a another stupid, lying pommy cunt.
.... Phil
Phil Allison
Jan 14, 2014, 10:11:57 PM1/14/14
to
dave
Jan 15, 2014, 8:17:54 AM1/15/14
to
On 01/14/2014 04:51 PM, Gareth Magennis wrote:
>
>
> "Phil Allison" wrote in message news:bjm352...@mid.individual.net...
>
>
>
>
>
> "Phil Allison" wrote in message news:bjm352...@mid.individual.net...
>
>
>
> FYI: Do you have two DC power supplies?
>
> Use one to provide a collector current of say 0.5 amps.
>
> Use the other to drive the base via a 1 kohm resistor so Ic is 0.5 amps.
>
> The ratio of currents will give you the correct Hfe for most power BJT
> devices.
>
>
>
> .... Phil
I have a Sencore Super Cricket I bought for $75. It squeals like a pig
>
> Use one to provide a collector current of say 0.5 amps.
>
> Use the other to drive the base via a 1 kohm resistor so Ic is 0.5 amps.
>
> The ratio of currents will give you the correct Hfe for most power BJT
> devices.
>
>
>
> .... Phil
when phase inverted 1kHz square waves are detected. It is great as a
go/no-go in-circuit tester. Out of circuit I use a $15 Chinese
transistor checker for beta matching.
I have 3 current limited bench supplies mfg by Trygon. One helped put
men on the moon.
Maynard A. Philbrook Jr.
Jan 15, 2014, 10:09:17 PM1/15/14
to
In article <EtSdnSo9L81UrkjP...@bt.com>,
sound....@btconnect.com says...
>
> "Phil Allison" <phi...@tpg.com.au> wrote in message
> news:bjkmq7...@mid.individual.net...
> >
> > "Gareth Magennis"
> > "Phil Allison"
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
sound....@btconnect.com says...
>
> "Phil Allison" <phi...@tpg.com.au> wrote in message
> news:bjkmq7...@mid.individual.net...
> >
> > "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 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 fucking good.
> >
> > See how that might be confusing ???
> >
> >
you need a real full range tester..
> >> 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 fucking good.
> >
> > See how that might be confusing ???
> >
> >
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
Maynard A. Philbrook Jr.
Jan 15, 2014, 10:12:38 PM1/15/14
to
In article <lb3e1n$e34$1...@dont-email.me>, grizzle...@comcast.net
says...
Jamie
says...
>
> Phil, we've (or at least I've) been putting up with your crap for a long time.
>
> When are you going to get professional help?
Where have you been, that is how professionals behave :)
> Phil, we've (or at least I've) been putting up with your crap for a long time.
>
> When are you going to get professional help?
Jamie
William Sommerwerck
Jan 16, 2014, 3:33:54 AM1/16/14
to
"Maynard A. Philbrook Jr." wrote in message
news:MPG.2d4118313...@news.eternal-september.org...
> Where have you been, that is how professionals behave. :)
I took a college course in psychology that started with a quiz to see what we
knew (or believed). One of the T/F statements was "Intelligent people are more
likely to have mental or emotional problems." I responded "true", but it's
supposedly not true. Phil seems to be the exception.
news:MPG.2d4118313...@news.eternal-september.org...
I took a college course in psychology that started with a quiz to see what we
knew (or believed). One of the T/F statements was "Intelligent people are more
likely to have mental or emotional problems." I responded "true", but it's
supposedly not true. Phil seems to be the exception.
Maynard A. Philbrook Jr.
Jan 16, 2014, 7:31:48 PM1/16/14
to
In article <lb85hm$lkj$1...@dont-email.me>, grizzle...@comcast.net
says...
Are you saying he's intelligent?
Jamie
says...
Jamie
Shaun
Jan 16, 2014, 8:18:19 PM1/16/14
to
"Gareth Magennis" wrote in message
>
>
>
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 fuck what
>
>
Yes I know Hfe is not constant, that is why I said the reading is
meaningless on such a low voltage checker.
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
whether or not it tests on this meter in the same ballpark as a known good
one.
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
Chris Jones
Jan 17, 2014, 10:04:30 AM1/17/14
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
Arfa Daily
Jan 17, 2014, 12:51:29 PM1/17/14
to
"William Sommerwerck" <grizzle...@comcast.net> wrote in message
news:lb3cb0$4ac$1...@dont-email.me...
> 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
Phil Allison
Jan 17, 2014, 6:19:46 PM1/17/14
to
"Chris Jones"
> It is easy to believe that measuring instruments with a digital display
> are always right but sometimes they aren't.
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
Phil Allison
Jan 17, 2014, 7:54:30 PM1/17/14
to
"Arfa Daily= anonymous worm "
> 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.
Either make your complaint in plain English, with all the details or shut
the fuck up.
> 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 ...'
Component & test equipment warehouses like Farnell have all faced dwindling
sales and increased competition in the last few years - much of it because
of all the internet dealers, particularly eBay sellers in Asia.
However, if I want a particularly high quality component, something bit
unusual or just to be certain I am not getting supplied someone's rejects -
then I buy from Farnell ( aka " Element 14" now).
BTW:
How typical of sleazy, anonymous little worms like AD to slander people like
this.
Peeeeuuukkkkk.............
... Phil
Arfa Daily
Jan 17, 2014, 8:36:48 PM1/17/14
to
news:bju1lp...@mid.individual.net...
>
> "Arfa Daily= anonymous worm "
Oh you juvenile sad little man ...
>
>> 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.
>
>
> ** WTF is that nonsense supposed to mean ??
>
> Either make your complaint in plain English, with all the details or shut
> the fuck up.
Was I talking to you, you fucked up Aussie twat ? Just shut the fuck up
yourself and piss off back under your rock you dopey bastard ... And that
is plain English, not the fucked-up bastardised version that you speak down
there on the bottom of the world. If you can't understand it, that's your
problem, not mine.
>
>
>> 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 ...'
>
>
> ** All businesses are out to make money, all the time, or they fail.
You really are a dopey twat. Fuck off and get a life ...
>
> Component & test equipment warehouses like Farnell have all faced
> dwindling sales and increased competition in the last few years - much of
> it because of all the internet dealers, particularly eBay sellers in Asia.
>
> However, if I want a particularly high quality component, something bit
> unusual or just to be certain I am not getting supplied someone's
Arfa
>
> Peeeeuuukkkkk.............
>
>
>
> ... Phil
>
>
>
>
>
> "Arfa Daily= anonymous worm "
Oh you juvenile sad little man ...
>
>> 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.
>
>
> ** WTF is that nonsense supposed to mean ??
>
> Either make your complaint in plain English, with all the details or shut
> the fuck up.
yourself and piss off back under your rock you dopey bastard ... And that
is plain English, not the fucked-up bastardised version that you speak down
there on the bottom of the world. If you can't understand it, that's your
problem, not mine.
>
>
>> 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 ...'
>
>
> ** All businesses are out to make money, all the time, or they fail.
>
> Component & test equipment warehouses like Farnell have all faced
> dwindling sales and increased competition in the last few years - much of
> it because of all the internet dealers, particularly eBay sellers in Asia.
>
> However, if I want a particularly high quality component, something bit
> unusual or just to be certain I am not getting supplied someone's
> ejects - then I buy from Farnell ( aka " Element 14" now).
>
>
> BTW:
>
> How typical of sleazy, anonymous little worms like AD to slander people
> like this.
What, like you never do ? You hypocritical arsewipe ...
>
>
> BTW:
>
> How typical of sleazy, anonymous little worms like AD to slander people
> like this.
Arfa
>
> Peeeeuuukkkkk.............
>
>
>
> ... Phil
>
>
>
>
Phil Allison
Jan 17, 2014, 8:39:17 PM1/17/14
to
"Phil Allison"
this.
Peeeeuuukkkkk.............
... Phil
Arfa Daily
Jan 18, 2014, 7:49:21 AM1/18/14
to
news:bju49o...@mid.individual.net...
size twelves. Gareth suspects that Farnell may - and I stress 'may' - have
unknowingly supplied him with someone else's rejects. He may be mistaken
because of the testing methods he has used, but equally, he /may/ be right.
The whole reason that I use Farnell - now much less than I used to - is the
same as you, that is to get what /should/ be a top quality certified
product. But, as you say, they have faced stiff competition recently, so
who's to say that they haven't sought alternative suppliers to try to cut
their costs, and in so doing, have inadvertently fallen foul of some dubious
trader somewhere down the line.
Things that have rung my alarm bells, have been some power transistors that
I use to repair HK powered speakers. I always stick to the same ones, and
have always bought them from Farnell for years. Over the last year, I have
had some batches where the logo doesn't look 'quite' right, and ones from
the same batch haven't been very well matched. These amplifiers are very
well behaved, and for the most part, the only problem with them is failed
output transistors, often brought on by barely adequate heatsinking, dried
out heatsink paste, and airways clogged with dead sheep. There is a very
detailed repair and checking guide produced by the manufacturer, and if all
the tests check out, they can be considered good to go. I have repaired many
of these over the years, and never had a problem with repeat failures, until
the last year, when several have returned after only a couple of weeks, with
the same set of transistors failed. After replacing them again with newly
ordered ones, and checking all the conditions and adjusting as required,
these repeat failures have gone back to work, and not returned again. It may
be coincidence, but with 45 years experience in this business, it certainly
doesn't 'feel' like it.
There. Detailed enough for you ?
As to Farnell needing to make money, of course they do. But as ever, you
missed the point I was making as you rushed to dive down my throat with your
usual bucket-mouthed diatribe. Farnell have done themselves no favours with
their loyal customers, by starting to levy delivery charges on what they
consider to be 'small' orders. They built their business on the loyalty of
small customers, and have now kicked us all in the teeth by levying these
additional charges. I could maybe accept it if their prices weren't a
premium in the first place, or the postage charges weren't unrealistic, and
if they stopped sending everything by UPS. I don't care how good a deal they
get from UPS, it is not going to be cheaper than a Jiffy bag through Royal
Mail. Also, UPS vary their delivery route "for security reasons" so you
never know what time you are going to get stuff fro 8 am to 6 pm, and it' a
different driver every time, so they never get to learn where stuff can be
left, or who with if you're not in. Also, a lot of stuff is now shipped from
their Belgian warehouse. This can't be cheap, and on more than one occasion
recently, the stuff hasn't made it to me by the next day.
These are some of the main reasons that they have gone from being my
supplier of choice to my supplier of need, and talking to colleagues in the
trade, I am by no means alone in this. I expect that some kid fresh out of
university, has done some kind of study of their costings, without taking in
the broader picture, or their customer demographic, and come up with this
new business model, which must be losing them small customers in droves.
Alternatively, maybe they have just looked at their customer base and
decided fuck the small boys, we only want big corporate customers ...
For non-critical components, I now buy almost all everything from a couple
of eBay suppliers that for the moment I trust. So far, I have had no
problems with anything that I have bought. These suppliers both have very
reasonable prices, and ship by Royal Mail First Class, for free. One of them
will even do his best to source stuff for you.
Arfa
>
> "Phil Allison"
>
> "Arfa Daily= anonymous worm "
>
>
>> 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.
>
>
> ** WTF is that nonsense supposed to mean ??
>
> Either make your complaint in plain English, with all the details or shut
> the fuck up.
>
>
>> 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 ...'
>
>
> ** All businesses are out to make money, all the time, or they fail.
>
> Component & test equipment warehouses like Farnell have all faced
> dwindling
> sales and increased competition in the last few years - much of it
> because
> of all the internet dealers, particularly eBay sellers in Asia.
>
> However, if I want a particularly high quality component, something bit
> unusual or just to be certain I am not getting supplied someone's
> "Phil Allison"
>
> "Arfa Daily= anonymous worm "
>
>
>> 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.
>
>
> ** WTF is that nonsense supposed to mean ??
>
> Either make your complaint in plain English, with all the details or shut
> the fuck up.
>
>
>> 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 ...'
>
>
> ** All businesses are out to make money, all the time, or they fail.
>
> Component & test equipment warehouses like Farnell have all faced
> dwindling
> sales and increased competition in the last few years - much of it
> because
> of all the internet dealers, particularly eBay sellers in Asia.
>
> However, if I want a particularly high quality component, something bit
> unusual or just to be certain I am not getting supplied someone's
> ejects -
> then I buy from Farnell ( aka " Element 14" now).
>
And that's what we were trying to discuss before you jumped in with your
> then I buy from Farnell ( aka " Element 14" now).
>
size twelves. Gareth suspects that Farnell may - and I stress 'may' - have
unknowingly supplied him with someone else's rejects. He may be mistaken
because of the testing methods he has used, but equally, he /may/ be right.
The whole reason that I use Farnell - now much less than I used to - is the
same as you, that is to get what /should/ be a top quality certified
product. But, as you say, they have faced stiff competition recently, so
who's to say that they haven't sought alternative suppliers to try to cut
their costs, and in so doing, have inadvertently fallen foul of some dubious
trader somewhere down the line.
Things that have rung my alarm bells, have been some power transistors that
I use to repair HK powered speakers. I always stick to the same ones, and
have always bought them from Farnell for years. Over the last year, I have
had some batches where the logo doesn't look 'quite' right, and ones from
the same batch haven't been very well matched. These amplifiers are very
well behaved, and for the most part, the only problem with them is failed
output transistors, often brought on by barely adequate heatsinking, dried
out heatsink paste, and airways clogged with dead sheep. There is a very
detailed repair and checking guide produced by the manufacturer, and if all
the tests check out, they can be considered good to go. I have repaired many
of these over the years, and never had a problem with repeat failures, until
the last year, when several have returned after only a couple of weeks, with
the same set of transistors failed. After replacing them again with newly
ordered ones, and checking all the conditions and adjusting as required,
these repeat failures have gone back to work, and not returned again. It may
be coincidence, but with 45 years experience in this business, it certainly
doesn't 'feel' like it.
There. Detailed enough for you ?
As to Farnell needing to make money, of course they do. But as ever, you
missed the point I was making as you rushed to dive down my throat with your
usual bucket-mouthed diatribe. Farnell have done themselves no favours with
their loyal customers, by starting to levy delivery charges on what they
consider to be 'small' orders. They built their business on the loyalty of
small customers, and have now kicked us all in the teeth by levying these
additional charges. I could maybe accept it if their prices weren't a
premium in the first place, or the postage charges weren't unrealistic, and
if they stopped sending everything by UPS. I don't care how good a deal they
get from UPS, it is not going to be cheaper than a Jiffy bag through Royal
Mail. Also, UPS vary their delivery route "for security reasons" so you
never know what time you are going to get stuff fro 8 am to 6 pm, and it' a
different driver every time, so they never get to learn where stuff can be
left, or who with if you're not in. Also, a lot of stuff is now shipped from
their Belgian warehouse. This can't be cheap, and on more than one occasion
recently, the stuff hasn't made it to me by the next day.
These are some of the main reasons that they have gone from being my
supplier of choice to my supplier of need, and talking to colleagues in the
trade, I am by no means alone in this. I expect that some kid fresh out of
university, has done some kind of study of their costings, without taking in
the broader picture, or their customer demographic, and come up with this
new business model, which must be losing them small customers in droves.
Alternatively, maybe they have just looked at their customer base and
decided fuck the small boys, we only want big corporate customers ...
For non-critical components, I now buy almost all everything from a couple
of eBay suppliers that for the moment I trust. So far, I have had no
problems with anything that I have bought. These suppliers both have very
reasonable prices, and ship by Royal Mail First Class, for free. One of them
will even do his best to source stuff for you.
Arfa
Phil Allison
Jan 18, 2014, 8:02:21 AM1/18/14
to
"Arfa Daily = pommy cunthead "
( snip paranoid rave )
How typical of sleazy, anonymous pommy cunts like AD to slander
honest people like this.
Including me.
Peeeeuuukkkkkeeee .............
Hope his fucking cat dies.
.... Phil
Arfa Daily
Jan 18, 2014, 10:37:36 AM1/18/14
to
news:bjvc9f...@mid.individual.net...
would have got banged up in an asylum, you wobble-eyed lunatic, and it would
have been the best place for you. They would have kept you dosed up on horse
tranquilizers, and you would have never seen the light of day again, which
would have been a result for the whole world.
You asked for reasons why I commented on Farnell's recent performance. I
gave them, but dopey shithead that you are, you just come back with more of
your worthless bucket-mouthed crap, because you are clinically incapable of
rational thought.
I am sick and tired of you hijacking every fuckin thread on here trying to
show how superior you think you are. You are actually a low-life twat, who
deserves to get a serious kicking from someone to put you in your place. You
are not clever or even remotely interesting. Everybody on here, without
exception, thinks that you are a stupid bastard, and about the worst advert
for the Australian nation, that there could possibly be.
Now do us all a favour and fuck off and get some help before you hurt
yourself, and if you can't do that, get back in your darkened room, and
don't come out until I tell you you can.
Fucking arsehole
>
> Peeeeuuukkkkkeeee .............
>
> Hope his fucking cat dies.
You sad, sad mental deficient ...
Arfa
>
>
>
>
> .... Phil
>
>
>
>
> "Arfa Daily = pommy cunthead "
>
> ( snip paranoid rave )
>
>
> How typical of sleazy, anonymous pommy cunts like AD to slander
> honest people like this.
>
> Including me.
You ??!! Honest ??!! What an arrogant dickhead you are. 40 years ago, you
> "Arfa Daily = pommy cunthead "
>
> ( snip paranoid rave )
>
>
> How typical of sleazy, anonymous pommy cunts like AD to slander
> honest people like this.
>
> Including me.
would have got banged up in an asylum, you wobble-eyed lunatic, and it would
have been the best place for you. They would have kept you dosed up on horse
tranquilizers, and you would have never seen the light of day again, which
would have been a result for the whole world.
You asked for reasons why I commented on Farnell's recent performance. I
gave them, but dopey shithead that you are, you just come back with more of
your worthless bucket-mouthed crap, because you are clinically incapable of
rational thought.
I am sick and tired of you hijacking every fuckin thread on here trying to
show how superior you think you are. You are actually a low-life twat, who
deserves to get a serious kicking from someone to put you in your place. You
are not clever or even remotely interesting. Everybody on here, without
exception, thinks that you are a stupid bastard, and about the worst advert
for the Australian nation, that there could possibly be.
Now do us all a favour and fuck off and get some help before you hurt
yourself, and if you can't do that, get back in your darkened room, and
don't come out until I tell you you can.
Fucking arsehole
>
> Peeeeuuukkkkkeeee .............
>
> Hope his fucking cat dies.
Arfa
>
>
>
>
> .... Phil
>
>
>
Gareth Magennis
Jan 18, 2014, 3:41:16 PM1/18/14
to
I have had a few alarm bells from Farnell recently.
Here's one - I had an old Lexicon 224 reverb to repair that had a problem
with the crowbar circuitry on the 5v line.
It used a 6vsomething Zener and a Triac to short out said line should it
rise above 6vsomethingelse volts.
Which it was doing on an extremely intermittent basis. Hard to determine if
the problem was the supply or the protection.
Anyway, after days of testing and discovering it was the protection, I
ordered the appropriate 6vsomthing zeners from Farnell.
Fortunately for me, I decided to construct a quick test rig just to make
sure the new Zener and Triac did indeed go short at the required
overvoltage.
Well it didn't.
It turned out these 6vsomething zeners were nothing of the sort. I couldn't
make them breakdown with my bench supply at 30v. It was not possible to
tell from the markings what they were.
I got these replaced with proper Zeners, and then the rig tripped out at the
less than 7 volts it was supposed to do.
Had I just fitted this zener without checking it was what it said it was,
the 224 would have been vulnerable to the 5v line going hugely overvoltage
and taking out every single digital IC in the unit. (100's of them)
This is, in fact, the VERY reason I chose to try and test the TIP35C
transistors before installing them in the Power Amp.
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.
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.
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.
I suspect the other 2 will be similar, but I will not be putting any of
these into a Power Amp.
At less than £1 each I think Farnell can afford another 4 my dodgy old
tester doesn't have a problem with.
Cheers,
Gareth.
Phil Allison
Jan 18, 2014, 9:08:01 PM1/18/14
to
"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.
> 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.
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.
.... Phil
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