NPN in unusual quadrant...

[John Larkin]

On Thu, 07 Sep 2023 04:58:57 GMT, Jan Panteltje <alien@comet.invalid>
wrote:

On a sunny day (Wed, 6 Sep 2023 22:56:12 +0000) it happened chrisq
devzero@nospam.com> wrote in <udb02d$2m6li$1@dont-email.me>:

On 9/6/23 22:34, John Larkin wrote:
On Wed, 6 Sep 2023 14:34:12 -0700 (PDT), John Smiht
utube.jocjo@xoxy.net> wrote:

On Wednesday, September 6, 2023 at 2:59:10?PM UTC-5, John Larkin wrote:
On Wed, 6 Sep 2023 19:19:20 +0100, piglet <erichp...@hotmail.com
wrote:
On 06/09/2023 01:04, John Larkin wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?


If the collector is already positive
That was a stated condition
and pullup resistor is not
extremely high then I think not much detectable will happen even once
the Veb junction breaks down.
\"Detectable\" can include amps or picoamps of currents.

Curious that nobody seems to address this case.

How could the information be used? It seems to have not been needed in the past, yes?

I\'d expect that understanding transistors is a generally good thing to
do. Looking at schematics on the web, it seems like few people do.

If it behaves as I suspect it may, I might have a use for it.


Back in the 60\'s/70\'s there were some germanium transistors
marketed for avalanche pulse generator work. May have been
Mullard / Philips, but don\'t remember any circuit details.

Years ago, found myself fixing more than a few high power
audio amps and built a simple breakdown tester with a variac,
stepdown transformer, limiting resistor and full wave rectifer.
Got some interesting effects at breakdown, very high frequency
oscillation on the scope. 2n3055 class power devices, normally
quite low frequency use. Interesting effect, perhaps similar
to other weird stuff of the time, like impatt diodes...

Yes, and not all 2N3055 were the same, different manufactures.. diffferent ft
Build quite a few audio amps with those.
https://en.m.wikipedia.org/wiki/2N3055

The old slow klunky RCA 3055\'s were tough. Fairchild made a \"2N3055\"
that had a tiny chip, was very fast, and tended to blow up.

Same likely goes for John Larkin\'s experiment,
And manufacturers can change process any time, not something recommended to use out of spec.

That\'s a problem these days, getti9ng consistent parts, even from one
manufacturer. Data sheets don\'t tell the whole story and in fact try
to hide hazards.

Sometimes, to get performance, you do what works.

We need a web site, icbugs.com or something where people report parts
issues.

 

[John Smiht]

On Thursday, September 7, 2023 at 11:57:05 AM UTC-5, John Larkin wrote:

On Thu, 07 Sep 2023 04:58:57 GMT, Jan Panteltje <al...@comet.invalid
wrote:
On a sunny day (Wed, 6 Sep 2023 22:56:12 +0000) it happened chrisq
dev...@nospam.com> wrote in <udb02d$2m6li$1...@dont-email.me>:

On 9/6/23 22:34, John Larkin wrote:
On Wed, 6 Sep 2023 14:34:12 -0700 (PDT), John Smiht
utube...@xoxy.net> wrote:

On Wednesday, September 6, 2023 at 2:59:10?PM UTC-5, John Larkin wrote:
On Wed, 6 Sep 2023 19:19:20 +0100, piglet <erichp...@hotmail.com
wrote:
On 06/09/2023 01:04, John Larkin wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?


If the collector is already positive
That was a stated condition
and pullup resistor is not
extremely high then I think not much detectable will happen even once
the Veb junction breaks down.
\"Detectable\" can include amps or picoamps of currents.

Curious that nobody seems to address this case.

How could the information be used? It seems to have not been needed in the past, yes?

I\'d expect that understanding transistors is a generally good thing to
do. Looking at schematics on the web, it seems like few people do.

If it behaves as I suspect it may, I might have a use for it.


Back in the 60\'s/70\'s there were some germanium transistors
marketed for avalanche pulse generator work. May have been
Mullard / Philips, but don\'t remember any circuit details.

Years ago, found myself fixing more than a few high power
audio amps and built a simple breakdown tester with a variac,
stepdown transformer, limiting resistor and full wave rectifer.
Got some interesting effects at breakdown, very high frequency
oscillation on the scope. 2n3055 class power devices, normally
quite low frequency use. Interesting effect, perhaps similar
to other weird stuff of the time, like impatt diodes...

Yes, and not all 2N3055 were the same, different manufactures.. diffferent ft
Build quite a few audio amps with those.
https://en.m.wikipedia.org/wiki/2N3055
The old slow klunky RCA 3055\'s were tough. Fairchild made a \"2N3055\"
that had a tiny chip, was very fast, and tended to blow up.

Same likely goes for John Larkin\'s experiment,
And manufacturers can change process any time, not something recommended to use out of spec.
That\'s a problem these days, getti9ng consistent parts, even from one
manufacturer. Data sheets don\'t tell the whole story and in fact try
to hide hazards.

Sometimes, to get performance, you do what works.

We need a web site, icbugs.com or something where people report parts
issues.

Cool! I like it! Please start one now.

 

[whit3rd]

On Thursday, September 7, 2023 at 9:48:42 AM UTC-7, John Larkin wrote:

On 06/09/2023 01:04, John Larkin wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor.. What
happens?

... I was thinking that my original quadrant comment could suggest
a mode where the b-e zener makes noise and the c-b junction amplifies
it. That depends on where the zener-inspired carriers go.

Oh, that\'s obvious; breakdown of B-E is mainly dominated by carriers from the emitter,
because there are so many of them (base is lightly doped). Those carriers
are repelled by the collector (+ bias on collector, and emitter of NPN is shooting
holes).

Main effect I\'d expect is aging of the surface, leading to base leakage if you
ever revert the bias to normal transresistance operation.

 

[Jasen Betts]

On 2023-09-06, piglet <erichpwagner@hotmail.com> wrote:

On 06/09/2023 01:04, John Larkin wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?


If the collector is already positive and pullup resistor is not
extremely high then I think not much detectable will happen even once
the Veb junction breaks down. But if the collector is open circuit or
very lightly loaded then the collector should show that photo-electric
effect \"the pease conundrum\" we discussed back in 2015. Whereby the E-B
avalanching junction emits light that the C-B junction does a
photo-diode act on?

but would the E-B reverse breakdown produce photons?

piglet

--
Jasen.
🇺🇦 Слава Україні

 

[Anthony William Sloman]

On Saturday, September 9, 2023 at 10:00:59 AM UTC+10, Jasen Betts wrote:

On 2023-09-06, piglet <erichp...@hotmail.com> wrote:
On 06/09/2023 01:04, John Larkin wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?


If the collector is already positive and pullup resistor is not
extremely high then I think not much detectable will happen even once
the Veb junction breaks down. But if the collector is open circuit or
very lightly loaded then the collector should show that photo-electric
effect \"the pease conundrum\" we discussed back in 2015. Whereby the E-B
avalanching junction emits light that the C-B junction does a
photo-diode act on?

but would the E-B reverse breakdown produce photons?

It always seems to. The packaging determines whether you can see them. There was a thread where the issue came up about a decade ago. mainly about whether zener diodes could oscillate - theye don\'t seem to - but avalanche diodes - anything that breaks down at much over 5V - can look as if that\'s what\'s going on.

--
Bill Sloman, Sydney

 

[piglet]

On 09/09/2023 00:46, Jasen Betts wrote:

On 2023-09-06, piglet <erichpwagner@hotmail.com> wrote:
On 06/09/2023 01:04, John Larkin wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?


If the collector is already positive and pullup resistor is not
extremely high then I think not much detectable will happen even once
the Veb junction breaks down. But if the collector is open circuit or
very lightly loaded then the collector should show that photo-electric
effect \"the pease conundrum\" we discussed back in 2015. Whereby the E-B
avalanching junction emits light that the C-B junction does a
photo-diode act on?

but would the E-B reverse breakdown produce photons?


piglet

Yes. Cut the top off a TO-18 or TO-5 metal can transistor and see for
yourself!

Back in fall 2015 we discussed this and I posted some photos. I cannot
recall the current but I think was in the region of 10-20mA the light
was clearly visible with ceiling lights off. To the eye it looked
silvery-gray but the phone camera showed orange, maybe because there was
a IR component to it?

Robert Pease described the effect after seeing little speckles of light
as op-amps were offset trimmed by the zener-zap technique (AFAIK an
array of sacrificial junctions selectively zapped, a kind of anti-fuse,
the zapped structure becoming a short).

piglet

 

[Piglet]

On 06/09/2023 03:38, John Larkin wrote:

On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:
On Wed, 6 Sep 2023 00:58:11 -0000 (UTC), Jasen Betts
usenet@revmaps.no-ip.org> wrote:

On 2023-09-06, John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

The base current is limited. But what happens?



Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.

Did you try it? I did today with a junk box NPN and results are kind of
as expected:

<https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1>

piglet

 

[Ricky]

On Sunday, September 10, 2023 at 8:57:03 AM UTC-4, Piglet wrote:

On 06/09/2023 03:38, John Larkin wrote:
On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:
On Wed, 6 Sep 2023 00:58:11 -0000 (UTC), Jasen Betts
use...@revmaps.no-ip.org> wrote:

On 2023-09-06, John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

The base current is limited. But what happens?



Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.

Did you try it? I did today with a junk box NPN and results are kind of
as expected:

https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1

Does the collector current go through the base, or the emitter?

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[John Larkin]

On Sun, 10 Sep 2023 13:56:54 +0100, Piglet <erichpwagner@hotmail.com>
wrote:

On 06/09/2023 03:38, John Larkin wrote:
On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:
On Wed, 6 Sep 2023 00:58:11 -0000 (UTC), Jasen Betts
usenet@revmaps.no-ip.org> wrote:

On 2023-09-06, John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

The base current is limited. But what happens?



Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.


Did you try it? I did today with a junk box NPN and results are kind of
as expected:

https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1

piglet

That\'s cool. The effective beta is around 70u, less than I would have
expected. Thanks.

I\'m still home recovering from a medical adventure, so I haven\'t tried
it.

 

[Anthony William Sloman]

On Monday, September 11, 2023 at 12:44:13 AM UTC+10, Ricky wrote:

On Sunday, September 10, 2023 at 8:57:03 AM UTC-4, Piglet wrote:
On 06/09/2023 03:38, John Larkin wrote:
On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:
On Wed, 6 Sep 2023 00:58:11 -0000 (UTC), Jasen Betts
use...@revmaps.no-ip.org> wrote:

On 2023-09-06, John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

The base current is limited. But what happens?



Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.

Did you try it? I did today with a junk box NPN and results are kind of
as expected:

https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1

Does the collector current go through the base, or the emitter?

All of it goes through the base, but the bulk of it ends up in the emitter. That\'s how transistors work.

--
Bill Sloman, Sydney

 

[Jan Panteltje]

On a sunny day (Sun, 10 Sep 2023 13:56:54 +0100) it happened Piglet
<erichpwagner@hotmail.com> wrote in <udkeen$isne$1@dont-email.me>:

On 06/09/2023 03:38, John Larkin wrote:
On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:
On Wed, 6 Sep 2023 00:58:11 -0000 (UTC), Jasen Betts
usenet@revmaps.no-ip.org> wrote:

On 2023-09-06, John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

The base current is limited. But what happens?



Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.


Did you try it? I did today with a junk box NPN and results are kind of
as expected:

https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1

Interesting!

 

[piglet]

On 10/09/2023 15:44, Ricky wrote:

On Sunday, September 10, 2023 at 8:57:03 AM UTC-4, Piglet wrote:
On 06/09/2023 03:38, John Larkin wrote:
On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:
On Wed, 6 Sep 2023 00:58:11 -0000 (UTC), Jasen Betts
use...@revmaps.no-ip.org> wrote:

On 2023-09-06, John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

The base current is limited. But what happens?



Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.

Did you try it? I did today with a junk box NPN and results are kind of
as expected:

https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1

Does the collector current go through the base, or the emitter?

I took the photo of those measurements before trying changing the
collector voltage supply. Ic did not change from the Vc=10V value
despite varying Vc from zero to 20V. I think that ties in with the
collector current being the photo-diode effect in the CB junction and so
therefore the return path would be through the base wire.

piglet

 

[John Smiht]

On Sunday, September 10, 2023 at 7:57:03 AM UTC-5, Piglet wrote:

On 06/09/2023 03:38, John Larkin wrote:
On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:
On Wed, 6 Sep 2023 00:58:11 -0000 (UTC), Jasen Betts
use...@revmaps.no-ip.org> wrote:

On 2023-09-06, John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

The base current is limited. But what happens?



Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.

Did you try it? I did today with a junk box NPN and results are kind of
as expected:

https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1

piglet

Very good, Piglet. That is very linear which I did not expect. Your data results in
Ic(nA) = 9.2536Veb - 74.33

 

[whit3rd]

On Sunday, September 10, 2023 at 12:55:12 PM UTC-7, John Smiht wrote:

On Sunday, September 10, 2023 at 7:57:03 AM UTC-5, Piglet wrote:
On 06/09/2023 03:38, John Larkin wrote:
On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.

Did you try it? I did today with a junk box NPN and results are kind of
as expected:

https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1

Very good, Piglet. That is very linear which I did not expect. Your data results in
Ic(nA) = 9.2536Veb - 74.33

So, to expect this in future, should we assume the B-E breakdown creates light, and
the collector current is a photodiode detecting that light? That does explain the
effect, and predicts emitter current proportional to collector current.

 

[piglet]

On 11/09/2023 4:16 am, whit3rd wrote:

On Sunday, September 10, 2023 at 12:55:12 PM UTC-7, John Smiht wrote:
On Sunday, September 10, 2023 at 7:57:03 AM UTC-5, Piglet wrote:
On 06/09/2023 03:38, John Larkin wrote:
On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.

Did you try it? I did today with a junk box NPN and results are kind of
as expected:

https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1

Very good, Piglet. That is very linear which I did not expect. Your data results in
Ic(nA) = 9.2536Veb - 74.33

So, to expect this in future, should we assume the B-E breakdown creates light, and
the collector current is a photodiode detecting that light? That does explain the
effect, and predicts emitter current proportional to collector current.

Yes, I think you meant collector current proportional to emitter
current? We did discusss all this back in 2015 under the thread \"a very
silly circuit\". About 25 years ago I think Stephen Woodward posted a
design idea in ED magazine using the effect to create a tiny negative
bias for opamp offset nulling in a positive rail only environment.

piglet

 

[legg]

On Sun, 10 Sep 2023 13:56:54 +0100, Piglet <erichpwagner@hotmail.com>
wrote:

On 06/09/2023 03:38, John Larkin wrote:
On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:
On Wed, 6 Sep 2023 00:58:11 -0000 (UTC), Jasen Betts
usenet@revmaps.no-ip.org> wrote:

On 2023-09-06, John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

The base current is limited. But what happens?



Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.


Did you try it? I did today with a junk box NPN and results are kind of
as expected:

https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1

piglet

There\'s some fences around here that only the privileged will
be allowed to paint.

I have a few tickets left .

RL

 

[John Larkin]

On Mon, 11 Sep 2023 11:01:46 +0100, piglet <erichpwagner@hotmail.com>
wrote:

On 11/09/2023 4:16 am, whit3rd wrote:
On Sunday, September 10, 2023 at 12:55:12?PM UTC-7, John Smiht wrote:
On Sunday, September 10, 2023 at 7:57:03?AM UTC-5, Piglet wrote:
On 06/09/2023 03:38, John Larkin wrote:
On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.

Did you try it? I did today with a junk box NPN and results are kind of
as expected:

https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1

Very good, Piglet. That is very linear which I did not expect. Your data results in
Ic(nA) = 9.2536Veb - 74.33

So, to expect this in future, should we assume the B-E breakdown creates light, and
the collector current is a photodiode detecting that light? That does explain the
effect, and predicts emitter current proportional to collector current.

Yes, I think you meant collector current proportional to emitter
current? We did discusss all this back in 2015 under the thread \"a very
silly circuit\". About 25 years ago I think Stephen Woodward posted a
design idea in ED magazine using the effect to create a tiny negative
bias for opamp offset nulling in a positive rail only environment.

piglet

PV optocouplers are great for genereating a quiet floating voltage,
but a transistor is cheaper.

I guess a regular, transistor type optocoupler, will generate a
floating voltage too. Something else to try.

 

[Phil Hobbs]

On 2023-09-11 08:32, John Larkin wrote:

On Mon, 11 Sep 2023 11:01:46 +0100, piglet <erichpwagner@hotmail.com
wrote:

On 11/09/2023 4:16 am, whit3rd wrote:
On Sunday, September 10, 2023 at 12:55:12?PM UTC-7, John Smiht wrote:
On Sunday, September 10, 2023 at 7:57:03?AM UTC-5, Piglet wrote:
On 06/09/2023 03:38, John Larkin wrote:
On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.

Did you try it? I did today with a junk box NPN and results are kind of
as expected:

https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1

Very good, Piglet. That is very linear which I did not expect. Your data results in
Ic(nA) = 9.2536Veb - 74.33

So, to expect this in future, should we assume the B-E breakdown creates light, and
the collector current is a photodiode detecting that light? That does explain the
effect, and predicts emitter current proportional to collector current.

Yes, I think you meant collector current proportional to emitter
current? We did discusss all this back in 2015 under the thread \"a very
silly circuit\". About 25 years ago I think Stephen Woodward posted a
design idea in ED magazine using the effect to create a tiny negative
bias for opamp offset nulling in a positive rail only environment.

piglet

PV optocouplers are great for genereating a quiet floating voltage,
but a transistor is cheaper.

I guess a regular, transistor type optocoupler, will generate a
floating voltage too. Something else to try.

It will, but you have to accept an efficiency on the order of CTR/beta,
i.e. something below 0.1%.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Phil Hobbs]

On 2023-09-11 08:30, legg wrote:

On Sun, 10 Sep 2023 13:56:54 +0100, Piglet <erichpwagner@hotmail.com
wrote:

On 06/09/2023 03:38, John Larkin wrote:
On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:
On Wed, 6 Sep 2023 00:58:11 -0000 (UTC), Jasen Betts
usenet@revmaps.no-ip.org> wrote:

On 2023-09-06, John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:
Imagine an NPN transistor. Ground the emitter and connect the
collector to some nice positive voltage.

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

The base current is limited. But what happens?



Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.


Did you try it? I did today with a junk box NPN and results are kind of
as expected:

https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1

piglet

There\'s some fences around here that only the privileged will
be allowed to paint.

I have a few tickets left .

RL

Well, you can go fishing any day.

Cheers

Phil Hobbs

 

[John Larkin]

On Mon, 11 Sep 2023 08:50:54 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2023-09-11 08:32, John Larkin wrote:
On Mon, 11 Sep 2023 11:01:46 +0100, piglet <erichpwagner@hotmail.com
wrote:

On 11/09/2023 4:16 am, whit3rd wrote:
On Sunday, September 10, 2023 at 12:55:12?PM UTC-7, John Smiht wrote:
On Sunday, September 10, 2023 at 7:57:03?AM UTC-5, Piglet wrote:
On 06/09/2023 03:38, John Larkin wrote:
On Wed, 6 Sep 2023 02:31:04 -0000 (UTC), Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

John Larkin <jla...@highlandSNIPMEtechnology.com> wrote:

Now pull the base negative, through a current-limiting resistor. What
happens?

Nothing until you exceed the emitter base reverse breakdown (or
collector base breakdown) voltage,

Not literally nothing, but not much interesting. It gets more
interesting when the base zeners.


Bitter-base is usually about 5V

Behaves kind of like a zener diode and damages the transistor.

Haven’t tried it, at least not on purpose, but I’d guess that when the
avalanche starts, most of the electrons will get sucked up by the
collector.

Since it’s the electrons and not the holes that do the avalanching in
silicon, that might partially suppress the avalanche. If that were true,
putting a positive voltage on the collector would make the base voltage
slightly more negative.

Cheers

Phil Hobbs

I\'d expect that zenering fills the b-e junction with lots of carriers,
and some find their way into the collector. I don\'t know how many.

Probably a lot less than foward base current.

I suppose I should try it.

Did you try it? I did today with a junk box NPN and results are kind of
as expected:

https://www.dropbox.com/scl/fi/rqr7n3uunosswqhx4e59h/NPNunusualQuadrant.pdf?rlkey=6kcqwz3soawgxws2ouhbdktq3&raw=1

Very good, Piglet. That is very linear which I did not expect. Your data results in
Ic(nA) = 9.2536Veb - 74.33

So, to expect this in future, should we assume the B-E breakdown creates light, and
the collector current is a photodiode detecting that light? That does explain the
effect, and predicts emitter current proportional to collector current.

Yes, I think you meant collector current proportional to emitter
current? We did discusss all this back in 2015 under the thread \"a very
silly circuit\". About 25 years ago I think Stephen Woodward posted a
design idea in ED magazine using the effect to create a tiny negative
bias for opamp offset nulling in a positive rail only environment.

piglet

PV optocouplers are great for genereating a quiet floating voltage,
but a transistor is cheaper.

I guess a regular, transistor type optocoupler, will generate a
floating voltage too. Something else to try.


It will, but you have to accept an efficiency on the order of CTR/beta,
i.e. something below 0.1%.

One could parallel the c-b and b-e junctions. Might help a little.

Cheers

Phil Hobbs

OK for some tiny bias thing, probably not for running motors.

This would be another curiosity measurement. You never know if such a
thing might be useful some day.