Uh-oh., Now I dood It.

[Watson A.Name - Watt Sun, Dark Remover]

I saw a bag of 1000 BC338 transistors on Ebay about ready for the
bidding to end, and they were going for only $11.50, so I bid on them
thinking that surely someone would outbid me. But they didn't! So
now I'm the buyer of 1000 for only $12.50 plus $4 s&h, about a penny
and a half each. Like I now have a lifetime supply of BC338s. Said
they were new, and pic showed them in a labeled bag, but they might
still be picked over and have low gain or whatever.

I have to figure out how to use these up in my LED flashlights.
They're about the same as a 2N4401, except capable of a bit more
collector current. The BC337s I've been using work well, so I think
I'll have a lotta uses for them. Oh, well..

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
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Don't be ripped off by the big book dealers. Go to the URL
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Just when you thought you had all this figured out, the gov't
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@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Dave VanHorn]

I have to figure out how to use these up in my LED flashlights.
They're about the same as a 2N4401, except capable of a bit more
collector current. The BC337s I've been using work well, so I think
I'll have a lotta uses for them. Oh, well..

I bought 1000 each of 2N3904 and 2N3906 about 12 years ago.
I'm getting a little low on the 04's.

 

[Mark (UK)]

Hiya!

Get a dolls house, wire 50 of them in parallel across a mains cable.
Place them throughout the dolls house, and make your own hollywood
blockbuster exploding house effect!!

In seriousness tho, there are good buys to be had on E, as long as you
can use the things you buy - I've baught tubes of ICs years ago that are
still sitting here now, never got round to using them!

Yours, Mark.

 

[Watson A.Name - Watt Sun, Dark Remover]

Hiya!

Get a dolls house, wire 50 of them in parallel across a mains cable.
Place them throughout the dolls house, and make your own hollywood
blockbuster exploding house effect!!

Sounds like a real blast! ;-)

However I'd use some real firecrackers for real FX.

I got a Q for all. These BC338s ae capable of handling an amp, as a
transistor of course. WHat I need are some high conductance diodes
that can handle high currents - less than an amp, maybe a half amp -
and are reasonably fast switching. I was thinking of connecting the
base and emitter together and using the collector junction as a diode.
I fighre it should handle at least a couple hundred mA, maybe more.
And since it's a fairly fast transistor, the diode should be so, too.
Has anyone done somerthing like this? Anyone tried to measure the
characteristics in a curve tracer?

I saw a schematic of an RF osc using 2 or 3 2N4401s connected as
diodes as varicaps to modulate the oscillator. Thanks.

In seriousness tho, there are good buys to be had on E, as long as you
can use the things you buy - I've baught tubes of ICs years ago that are
still sitting here now, never got round to using them!

Yours, Mark.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Johnboy]

I can use a hundred or so, what can I trade you?
I have lots of electronic stuff, components, and so on.
I am across the pond, in the states, so I need to keep
the package small.

 

[Watson A.Name - Watt Sun, Dark Remover]

I can use a hundred or so, what can I trade you?
I have lots of electronic stuff, components, and so on.
I am across the pond, in the states, so I need to keep
the package small.

Email, observing anti-spam precautions in my .sig.


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Walter Harley]

I got a Q for all. These BC338s ae capable of handling an amp, as a
transistor of course. WHat I need are some high conductance diodes
that can handle high currents - less than an amp, maybe a half amp -
and are reasonably fast switching. I was thinking of connecting the
base and emitter together and using the collector junction as a diode.
I fighre it should handle at least a couple hundred mA, maybe more.
And since it's a fairly fast transistor, the diode should be so, too.
Has anyone done somerthing like this? Anyone tried to measure the
characteristics in a curve tracer?

Bob Pease talks about using diode-connected transistors; e.g., as
low-leakage diodes. But I think he means with base and collector connected,
not base and emitter. If you poke around on the National web site for some
of his online seminars I'm sure you can find info, including curves.

Half an amp times 0.7V is 0.35W. That's a fair amount of power for
something that only has tiny little transistor leads; diodes get rid of
their current through their big thick leads.

 

[Watson A.Name - Watt Sun, Dark Remover]

Bob Pease talks about using diode-connected transistors; e.g., as
low-leakage diodes. But I think he means with base and collector connected,
not base and emitter. If you poke around on the National web site for some
of his online seminars I'm sure you can find info, including curves.

Half an amp times 0.7V is 0.35W. That's a fair amount of power for
something that only has tiny little transistor leads; diodes get rid of
their current through their big thick leads.

Thanks. The BC338 transistors are rated for an amp and 625 mW, so it
should still handle that current. The transistor die is bonded to the
collector lead, which is thicker than the other leads. If the
collector lead is mounted close to the circuit board, most of the heat
will be conducted away to the copper PCB traces. And now that I'll be
getting a thousand of them, there's nothing saying I can't parallel a
few. ;-)


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Walter Harley]

Thanks. The BC338 transistors are rated for an amp and 625 mW, so it
should still handle that current. The transistor die is bonded to the
collector lead, which is thicker than the other leads. If the
collector lead is mounted close to the circuit board, most of the heat
will be conducted away to the copper PCB traces. And now that I'll be
getting a thousand of them, there's nothing saying I can't parallel a
few. ;-)

Current hogging. And by the time you get a couple of low-value resistors to
fix that, you might as well have just shelled out the dough for some bigger
diodes.

(Hey! You callin' me a current hog? Well, you're a, a, a voltage weevil!
Yeah!)

 

[Watson A.Name - Watt Sun, Dark Remover]

Current hogging. And by the time you get a couple of low-value resistors to
fix that, you might as well have just shelled out the dough for some bigger
diodes.

(Hey! You callin' me a current hog? Well, you're a, a, a voltage weevil!
Yeah!)

Heh-heh. Actually I figured that by coupling the DCTs closely
thermally, the current hogging wouldn't be a problem. Just twist the
leads together near the case. No resistors, no problem. I can also
use some 1N5817 1A Schottky diodes; I got plenty of them. But I want
to use the transistors since I have a bunch. So back to the original
Q. How good a diode is a BC338 transistor with the E and B tied
together and the collector used as the diode junction? Should I put a
few on a PS and run various currents thru them and get some idea of
the V drop at currents in the hundreds of mA? How would it be done in
a commercial setting? Would they put a few on a curve tracer and run
up the current to see how they performed? Thanks. Happy holidays.


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Watson A.Name - Watt Sun, Dark Remover]

Heh-heh. Actually I figured that by coupling the DCTs closely
thermally, the current hogging wouldn't be a problem. Just twist the
leads together near the case. No resistors, no problem. I can also
use some 1N5817 1A Schottky diodes; I got plenty of them. But I want
to use the transistors since I have a bunch. So back to the original
Q. How good a diode is a BC338 transistor with the E and B tied
together and the collector used as the diode junction? Should I put a
few on a PS and run various currents thru them and get some idea of
the V drop at currents in the hundreds of mA? How would it be done in
a commercial setting? Would they put a few on a curve tracer and run
up the current to see how they performed? Thanks. Happy holidays.

I went to the Central Semi website and checked out their reference
manual. They have a .PDF index with the transistor types with each
type a hot link that you can click on, which then downloads a .PDF of
the actual die or chip that's used in that transistor.
http://www.centralsemi.com/pdf/index.pdf
Click the page advance arrow until you go to 6 of 15. Then click on
2N3904 - CP192. You can see that the chip or die is only 13 x 17
mils. Then go to BC338 and you can see that the chip or die is 31 mil
square, which is substantially larger area, and that's why it can
handle a lot more current.


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@