NPN protective zener

On a sunny day (Sun, 23 Jun 2019 11:21:56 -0700 (PDT)) it happened Lasse
Langwadt Christensen <langwadt@fonz.dk> wrote

den 23. juni 2019 kl. 19.26.24 UTC+2 skrev Jan Panteltje:
I am at a loss here:
https://www.acronymattic.com/SMU.html

Source Measure Unit, ~ a fancy powersupply
Click to expand...

Thank you.
 
On Sunday, June 23, 2019 at 3:09:39 PM UTC-4, Lasse Langwadt Christensen wrote:
søndag den 23. juni 2019 kl. 20.29.10 UTC+2 skrev Rick C:
On Sunday, June 23, 2019 at 2:22:00 PM UTC-4, Lasse Langwadt Christensen wrote:
søndag den 23. juni 2019 kl. 19.26.24 UTC+2 skrev Jan Panteltje:
On a sunny day (23 Jun 2019 10:14:04 -0700) it happened Winfield Hill
winfieldhill@yahoo.com> wrote in <qeoc0s02rrd@drn.newsguy.com>:

Jan Panteltje wrote...

Winfield makes an assumption,
only testing can confirm it stays working
as a zener in the long run.
If anything physically changes in that transistor
why should it not affect the Vbe zener.
Not testing is bad practice.

Don't worry, my setup is test-ready. I'm
using a $10k SMU that I got on eBay for $5k,
and it has scripts for doing extended tests,
measuring as you go. But I would also add a
comment, this isn't my scheme, many have been
using it for decades, and I suppose some did
thorough tests. Also, events this is meant
to protect against don't happen very often.
For now, the 10A projection is a dotted line
in the book, but it'll be tested before going
to publication.

OK, well I am curious as to what you will find,.
5 k$ is a lot of money, something that generates 10A
pulses should not be that expensive?
Very long time ago boss asked me if I could design a transistor curve tracer.
Took a day or 2, used relays too, and a scope.

I am at a loss here:
https://www.acronymattic.com/SMU.html

Source Measure Unit, ~ a fancy powersupply

Seems like an odd name for that. I assume it has some special properties beyond a power supply which the name refers to?


https://en.wikipedia.org/wiki/Source_measure_unit#SMU_vs._Power_Supply

;)
Click to expand...

Thanks. It literally didn't occur to me Wikipedia would have a page on this.

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209
 
On a sunny day (Sun, 23 Jun 2019 12:09:36 -0700 (PDT)) it happened Lasse
Langwadt Christensen <langwadt@fonz.dk> wrote in
<8c72fbde-ed5a-4a40-bb64-0014fff7951e@googlegroups.com>:

s=C3=B8ndag den 23. juni 2019 kl. 20.29.10 UTC+2 skrev Rick C:
On Sunday, June 23, 2019 at 2:22:00 PM UTC-4, Lasse Langwadt Christensen wrote:

s=C3=B8ndag den 23. juni 2019 kl. 19.26.24 UTC+2 skrev Jan Panteltje:
On a sunny day (23 Jun 2019 10:14:04 -0700) it happened Winfield Hill
winfieldhill@yahoo.com> wrote in <qeoc0s02rrd@drn.newsguy.com>:

Jan Panteltje wrote...

Winfield makes an assumption,
only testing can confirm it stays working
as a zener in the long run.
If anything physically changes in that transistor
why should it not affect the Vbe zener.
Not testing is bad practice.

Don't worry, my setup is test-ready. I'm
using a $10k SMU that I got on eBay for $5k,
and it has scripts for doing extended tests,
measuring as you go. But I would also add a
comment, this isn't my scheme, many have been
using it for decades, and I suppose some did
thorough tests. Also, events this is meant
to protect against don't happen very often.
For now, the 10A projection is a dotted line
in the book, but it'll be tested before going
to publication.

OK, well I am curious as to what you will find,.
5 k$ is a lot of money, something that generates 10A
pulses should not be that expensive?
Very long time ago boss asked me if I could design a transistor curve
tracer.
Took a day or 2, used relays too, and a scope.

I am at a loss here:
https://www.acronymattic.com/SMU.html

Source Measure Unit, ~ a fancy powersupply

Seems like an odd name for that. I assume it has some special properties
beyond a power supply which the name refers to?


https://en.wikipedia.org/wiki/Source_measure_unit#SMU_vs._Power_Supply

;)
Click to expand...

Somehow that brings up a picture of a DC coupled audio power amp with some current limiting.
 
søndag den 23. juni 2019 kl. 20.29.10 UTC+2 skrev Rick C:
On Sunday, June 23, 2019 at 2:22:00 PM UTC-4, Lasse Langwadt Christensen wrote:
søndag den 23. juni 2019 kl. 19.26.24 UTC+2 skrev Jan Panteltje:
On a sunny day (23 Jun 2019 10:14:04 -0700) it happened Winfield Hill
winfieldhill@yahoo.com> wrote in <qeoc0s02rrd@drn.newsguy.com>:

Jan Panteltje wrote...

Winfield makes an assumption,
only testing can confirm it stays working
as a zener in the long run.
If anything physically changes in that transistor
why should it not affect the Vbe zener.
Not testing is bad practice.

Don't worry, my setup is test-ready. I'm
using a $10k SMU that I got on eBay for $5k,
and it has scripts for doing extended tests,
measuring as you go. But I would also add a
comment, this isn't my scheme, many have been
using it for decades, and I suppose some did
thorough tests. Also, events this is meant
to protect against don't happen very often.
For now, the 10A projection is a dotted line
in the book, but it'll be tested before going
to publication.

OK, well I am curious as to what you will find,.
5 k$ is a lot of money, something that generates 10A
pulses should not be that expensive?
Very long time ago boss asked me if I could design a transistor curve tracer.
Took a day or 2, used relays too, and a scope.

I am at a loss here:
https://www.acronymattic.com/SMU.html

Source Measure Unit, ~ a fancy powersupply

Seems like an odd name for that. I assume it has some special properties beyond a power supply which the name refers to?
Click to expand...

https://en.wikipedia.org/wiki/Source_measure_unit#SMU_vs._Power_Supply

;)
 
On Sun, 23 Jun 2019 19:22:25 GMT, Jan Panteltje
<pNaOnStPeAlMtje@yahoo.com> wrote:

On a sunny day (Sun, 23 Jun 2019 12:09:36 -0700 (PDT)) it happened Lasse
Langwadt Christensen <langwadt@fonz.dk> wrote in
8c72fbde-ed5a-4a40-bb64-0014fff7951e@googlegroups.com>:

s=C3=B8ndag den 23. juni 2019 kl. 20.29.10 UTC+2 skrev Rick C:
On Sunday, June 23, 2019 at 2:22:00 PM UTC-4, Lasse Langwadt Christensen wrote:

s=C3=B8ndag den 23. juni 2019 kl. 19.26.24 UTC+2 skrev Jan Panteltje:
On a sunny day (23 Jun 2019 10:14:04 -0700) it happened Winfield Hill
winfieldhill@yahoo.com> wrote in <qeoc0s02rrd@drn.newsguy.com>:

Jan Panteltje wrote...

Winfield makes an assumption,
only testing can confirm it stays working
as a zener in the long run.
If anything physically changes in that transistor
why should it not affect the Vbe zener.
Not testing is bad practice.

Don't worry, my setup is test-ready. I'm
using a $10k SMU that I got on eBay for $5k,
and it has scripts for doing extended tests,
measuring as you go. But I would also add a
comment, this isn't my scheme, many have been
using it for decades, and I suppose some did
thorough tests. Also, events this is meant
to protect against don't happen very often.
For now, the 10A projection is a dotted line
in the book, but it'll be tested before going
to publication.

OK, well I am curious as to what you will find,.
5 k$ is a lot of money, something that generates 10A
pulses should not be that expensive?
Very long time ago boss asked me if I could design a transistor curve
tracer.
Took a day or 2, used relays too, and a scope.

I am at a loss here:
https://www.acronymattic.com/SMU.html

Source Measure Unit, ~ a fancy powersupply

Seems like an odd name for that. I assume it has some special properties
beyond a power supply which the name refers to?


https://en.wikipedia.org/wiki/Source_measure_unit#SMU_vs._Power_Supply

;)

Somehow that brings up a picture of a DC coupled audio power amp with some current limiting.
Click to expand...

But fully programmable and interfaced, nanovolts to hundreds of volts,
fA to amps, CV/CC, floating, and seriously accurate. Many of our test
racks include a Keysight SMU.

I've considered going into the SMU business, but it would be seriously
difficult.

It ought to measure capacitance too.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics
 
On Sun, 23 Jun 2019 13:50:31 -0700, John Larkin wrote:

I've considered going into the SMU business, but it would be seriously
difficult.
Click to expand...

Is this what all these snippets you've posted about pulse generators are
related to?



--
This message may be freely reproduced without limit or charge only via
the Usenet protocol. Reproduction in whole or part through other
protocols, whether for profit or not, is conditional upon a charge of
GBP10.00 per reproduction. Publication in this manner via non-Usenet
protocols constitutes acceptance of this condition.
 
On Sunday, June 23, 2019 at 12:39:23 PM UTC-4, Mikko OH2HVJ wrote:
whit3rd <whit3rd@gmail.com> writes:

Consider a UV LED inside the shield box; nothing discharges (leaks) better
than a photoconductor (and almost all insulators ARE at least a little
photoconductive).

A few milliseconds after the LED is turned off, the insulators will insulate
again.

Any experience on what is short enough wavelength for this ? I happen to
have a rather large stash of 280nm LEDs..
Huh, you should do the photo-electric effect with them...
Click to expand...

George H.
--
mikko
Click to expand...
 
On Sunday, June 23, 2019 at 9:39:23 AM UTC-7, Mikko OH2HVJ wrote:
> whit3rd <whit3rd@gmail.com> writes:

[about long settling times for low-current measurement]

Consider a UV LED inside the shield box; nothing discharges (leaks) better
than a photoconductor (and almost all insulators ARE at least a little
photoconductive).

Any experience on what is short enough wavelength for this ? I happen to
have a rather large stash of 280nm LEDs..
Click to expand...

My experience is mainly with ionizing X-rays, in a gas (capacitor),
also known as an ion chamber. For near-visible UV in an environment of
mixed materials (insulating polymers, coatings, printed wiring boards with mask and
epoxy/fiberglass insulation), I'd expect surface charges to dissipate but
cannot be sure how penetrating the radiation is, nor what materials are the
most sensitive.

280nm LEDs? is there any ozone generated? That's almost vacuum UV!
Is it a harmonic generation from a laser?
 
On a sunny day (Sun, 23 Jun 2019 13:50:31 -0700) it happened John Larkin
<jjlarkin@highlandtechnology.com> wrote in
<s8pvge9p5vsoqi079ee1009uqefn0pkqg3@4ax.com>:

On Sun, 23 Jun 2019 19:22:25 GMT, Jan Panteltje
pNaOnStPeAlMtje@yahoo.com> wrote:
https://en.wikipedia.org/wiki/Source_measure_unit#SMU_vs._Power_Supply

;)

Somehow that brings up a picture of a DC coupled audio power amp with some current limiting.

But fully programmable and interfaced, nanovolts to hundreds of volts,
fA to amps, CV/CC, floating, and seriously accurate.
Click to expand...

So HiFi audio amp for golden ears, that explains the price ;-)


Many of our test
racks include a Keysight SMU.

I've considered going into the SMU business, but it would be seriously
difficult.
Click to expand...

Market big enough?


>It ought to measure capacitance too.

There seems to be a tendency to make things (all things) that can do everything.
I bought a new Canon camera last week, and having had 3 and a lot of experience,
I almost got to the point of wanting to return it.
Anyways, reading the manual did help a bit....
It can do a lot of things, but the things I want it do???
Anyways macro mode works OK, one thing I use it for.
Zoom is very powerful too, if you can hold it still....
Beginning to like it.
 
On a sunny day (Sun, 23 Jun 2019 22:56:28 -0700 (PDT)) it happened whit3rd
<whit3rd@gmail.com> wrote in
<0969b8d8-8aa2-4932-94e4-d48ad6c57cd4@googlegroups.com>:

On Sunday, June 23, 2019 at 9:39:23 AM UTC-7, Mikko OH2HVJ wrote:
whit3rd <whit3rd@gmail.com> writes:

[about long settling times for low-current measurement]

Consider a UV LED inside the shield box; nothing discharges (leaks) better
than a photoconductor (and almost all insulators ARE at least a little
photoconductive).

Any experience on what is short enough wavelength for this ? I happen to
have a rather large stash of 280nm LEDs..

My experience is mainly with ionizing X-rays, in a gas (capacitor),
also known as an ion chamber. For near-visible UV in an environment of
mixed materials (insulating polymers, coatings, printed wiring boards with mask and
epoxy/fiberglass insulation), I'd expect surface charges to dissipate but
cannot be sure how penetrating the radiation is, nor what materials are the
most sensitive.

280nm LEDs? is there any ozone generated? That's almost vacuum UV!
Is it a harmonic generation from a laser?
Click to expand...

I still have an 220V UV EPROM erase tube, that should do.
http://panteltje.com/pub/UV_EPROM_erase_tube_IMG_7110.JPG
it would need to be mounted in a separate box shining in through some metal grid I suppose.
Fun shining that at some stuff.. fluorescence...

Have an UV flashlight to check banknotes too... No idea about the wavelength,
 
Mikko OH2HVJ wrote...
These are real LEDs from SETi ...
Click to expand...

What did SETi do with UV lEDs?
Hmm, SETi, lower-case intelligence?


--
Thanks,
- Win
 
whit3rd <whit3rd@gmail.com> writes:

My experience is mainly with ionizing X-rays, in a gas (capacitor),
also known as an ion chamber. For near-visible UV in an environment of
mixed materials (insulating polymers, coatings, printed wiring boards with mask and
epoxy/fiberglass insulation), I'd expect surface charges to dissipate but
cannot be sure how penetrating the radiation is, nor what materials are the
most sensitive.
Click to expand...

I'll try it out during the summer vacation!

280nm LEDs? is there any ozone generated? That's almost vacuum UV!
Is it a harmonic generation from a laser?
Click to expand...

There's basically no ozone generation with these ones - wavelenght is at
the limit of O3 generation and the power is in the 0.5mW region.
These are real LEDs from SETi, no doubling/tripling. Looks like they're
no longer marketing these (UVTOP-series), they're leftovers from a
project about 10 years ago.

--
mikko
 
On 24 Jun 2019 06:20:32 -0700, Winfield Hill <winfieldhill@yahoo.com>
wrote:

Mikko OH2HVJ wrote...

These are real LEDs from SETi ...

What did SETi do with UV lEDs?
Hmm, SETi, lower-case intelligence?
Click to expand...

Looking for dumb aliens.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics
 
On Sun, 23 Jun 2019 23:06:42 -0000 (UTC), Cursitor Doom
<curd@notformail.com> wrote:

On Sun, 23 Jun 2019 13:50:31 -0700, John Larkin wrote:

I've considered going into the SMU business, but it would be seriously
difficult.

Is this what all these snippets you've posted about pulse generators are
related to?
Click to expand...

No, that's a different business. We do both fast pulse stuff and
precision analog stuff, which are distinctly different technologies
and customers. We used to do NMR gradient drivers, which sort of
overlap.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics
 
On Mon, 24 Jun 2019 07:22:06 GMT, Jan Panteltje
<pNaOnStPeAlMtje@yahoo.com> wrote:

On a sunny day (Sun, 23 Jun 2019 13:50:31 -0700) it happened John Larkin
jjlarkin@highlandtechnology.com> wrote in
s8pvge9p5vsoqi079ee1009uqefn0pkqg3@4ax.com>:

On Sun, 23 Jun 2019 19:22:25 GMT, Jan Panteltje
pNaOnStPeAlMtje@yahoo.com> wrote:
https://en.wikipedia.org/wiki/Source_measure_unit#SMU_vs._Power_Supply

;)

Somehow that brings up a picture of a DC coupled audio power amp with some current limiting.

But fully programmable and interfaced, nanovolts to hundreds of volts,
fA to amps, CV/CC, floating, and seriously accurate.

So HiFi audio amp for golden ears, that explains the price ;-)
Click to expand...

I bet we could play music through the SMU, USB or Ethernet interface.




Many of our test
racks include a Keysight SMU.

I've considered going into the SMU business, but it would be seriously
difficult.

Market big enough?


It ought to measure capacitance too.

There seems to be a tendency to make things (all things) that can do everything.
I bought a new Canon camera last week, and having had 3 and a lot of experience,
I almost got to the point of wanting to return it.
Anyways, reading the manual did help a bit....
It can do a lot of things, but the things I want it do???
Anyways macro mode works OK, one thing I use it for.
Zoom is very powerful too, if you can hold it still....
Beginning to like it.
Click to expand...

I'd love to get semiconductor CV curves easily. The SMU would need two
channels that can also measure capacitance.


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
 
On 6/23/19 12:39 PM, Mikko OH2HVJ wrote:
whit3rd <whit3rd@gmail.com> writes:

Consider a UV LED inside the shield box; nothing discharges (leaks) better
than a photoconductor (and almost all insulators ARE at least a little
photoconductive).

A few milliseconds after the LED is turned off, the insulators will insulate
again.

Any experience on what is short enough wavelength for this ? I happen to
have a rather large stash of 280nm LEDs..

--
mikko
Click to expand...

Or you could make a laser-produced plasma by focusing down a pulsed YAG
laser. ;)

Cheers

Phil Hobbs

(Who actually has a patent on suppressing static charge inside
semiconductor litho tools by doing that. One of my old boss's enthusiasms.)

--
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
 
On 6/23/19 11:43 AM, mixed nuts wrote:
On 6/22/2019 1:58 PM, Winfield Hill wrote:
mixed nuts wrote...

Low noise transistors become noisy transistors after the b-e
junction has been zenered a few times. I didn't have an
opportunity to do a rigorous before-after gain comparison but it
didn't seem to change dramatically.

Others have observed a serious loss in beta. There are rumors of
ways to resurrect the poor beast, but if its role in life is as a
low-capacitance zener clamp, who cares? When it's wired up on a
PCB, with the base and collector shorted, there's little else that
it could ever do!

Just don't put them back in the drawer after you finish playing.
Click to expand...

The beta loss is indicative of progressive junction damage, which is
what would make me nervous about this idea. Sounds like a long-term
reliability headache.

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
 
I'd love to get semiconductor CV curves easily. The SMU would need two
channels that can also measure capacitance.
Click to expand...

Wire a couple of Boonton 72s in series with the SMUs!

Cheers

Phil Hobbs
 
On Mon, 24 Jun 2019 12:13:09 -0700 (PDT), pcdhobbs@gmail.com wrote:

I'd love to get semiconductor CV curves easily. The SMU would need two
channels that can also measure capacitance.

Wire a couple of Boonton 72s in series with the SMUs!

Cheers

Phil Hobbs
Click to expand...

Yes, they have bias inputs on the back. Where's the Ethernet
connector?

Didn't one of the Boontons have BCD out?


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
 
On Mon, 24 Jun 2019 14:01:51 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 6/23/19 11:43 AM, mixed nuts wrote:
On 6/22/2019 1:58 PM, Winfield Hill wrote:
mixed nuts wrote...

Low noise transistors become noisy transistors after the b-e
junction has been zenered a few times. I didn't have an
opportunity to do a rigorous before-after gain comparison but it
didn't seem to change dramatically.

Others have observed a serious loss in beta. There are rumors of
ways to resurrect the poor beast, but if its role in life is as a
low-capacitance zener clamp, who cares? When it's wired up on a
PCB, with the base and collector shorted, there's little else that
it could ever do!

Just don't put them back in the drawer after you finish playing.



The beta loss is indicative of progressive junction damage, which is
what would make me nervous about this idea. Sounds like a long-term
reliability headache.

Cheers

Phil Hobbs
Click to expand...

I ran a small NPN as a b-e zener for a week or so. The voltage
declined a bit, roughly 1% as I recall, and seemed to be leveling out.


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
 
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