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Exhausted

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  Exhausted  "David Eather" <eather@tpg.com.au> - 2016-03-16 15:53 +1000
    Re: Exhausted Klaus Kragelund <klauskvik@hotmail.com> - 2016-03-16 01:07 -0700
    Re: Exhausted George Herold <gherold@teachspin.com> - 2016-03-16 06:04 -0700
      Re: Exhausted "David Eather" <eather@tpg.com.au> - 2016-03-17 00:16 +1000
        Re: Exhausted Allan Herriman <allanherriman@hotmail.com> - 2016-03-16 16:35 +0000
          Re: Exhausted George Herold <gherold@teachspin.com> - 2016-03-16 11:15 -0700
            Re: Exhausted Allan Herriman <allanherriman@hotmail.com> - 2016-03-17 12:11 +0000
        Re: Exhausted mrdarrett@gmail.com - 2016-03-17 10:37 -0700
          Re: Exhausted "David Eather" <eather@tpg.com.au> - 2016-03-18 07:25 +1000
            Re: Exhausted mrdarrett@gmail.com - 2016-03-17 15:05 -0700
      Re: Exhausted Winfield Hill <hill@rowland.harvard.edu> - 2016-03-16 07:32 -0700
        Re: Exhausted George Herold <gherold@teachspin.com> - 2016-03-16 08:04 -0700
          Re: Exhausted Winfield Hill <hill@rowland.harvard.edu> - 2016-03-16 08:16 -0700
          Re: Exhausted John Larkin <jjlarkin@highlandtechnology.com> - 2016-03-16 10:32 -0700
            Re: Exhausted George Herold <gherold@teachspin.com> - 2016-03-16 11:08 -0700
              Re: Exhausted John Larkin <jjlarkin@highlandtechnology.com> - 2016-03-16 12:30 -0700
                Re: Exhausted Clifford Heath <no.spam@please.net> - 2016-03-17 06:47 +1100
                  Re: Exhausted John Larkin <jjlarkin@highlandtechnology.com> - 2016-03-16 17:01 -0700
                    Re: Exhausted Clifford Heath <no.spam@please.net> - 2016-03-17 07:01 +1100
                      Re: Exhausted John Larkin <jjlarkin@highlandtechnology.com> - 2016-03-16 17:27 -0700
                        Re: Exhausted Piotr Wyderski <peter.pan@neverland.mil> - 2016-03-17 17:35 +0100
                          Re: Exhausted John Larkin <jjlarkin@highlandtechnology.com> - 2016-03-17 10:13 -0700
                          Re: Exhausted Clifford Heath <no.spam@please.net> - 2016-03-18 11:38 +1100
                    Re: Exhausted dplatt@coop.radagast.org (Dave Platt) - 2016-03-16 17:17 -0700
                      Re: Exhausted Lasse Langwadt Christensen <langwadt@fonz.dk> - 2016-03-16 17:21 -0700
                        Re: Exhausted John Larkin <jjlarkin@highlandtechnology.com> - 2016-03-16 17:39 -0700
                          Re: Exhausted "Tim Williams" <tiwill@seventransistorlabs.com> - 2016-03-16 21:24 -0500
                            Re: Exhausted Phil Hobbs <pcdhobbs@gmail.com> - 2016-03-16 20:51 -0700
                          Re: Exhausted George Herold <gherold@teachspin.com> - 2016-03-16 20:21 -0700
                            Re: Exhausted John Larkin <jjlarkin@highlandtechnology.com> - 2016-03-16 21:16 -0700
                      Re: Exhausted John Larkin <jjlarkin@highlandtechnology.com> - 2016-03-16 17:34 -0700
                        Re: Exhausted "David Eather" <eather@tpg.com.au> - 2016-03-18 07:31 +1000
                    Re: Exhausted rickman <gnuarm@gmail.com> - 2016-03-17 00:01 -0400
                      Re: Exhausted Clifford Heath <no.spam@please.net> - 2016-03-17 14:09 +1100
                        Re: Exhausted John Larkin <jjlarkin@highlandtechnology.com> - 2016-03-17 09:01 -0700
                        Re: Exhausted Piotr Wyderski <peter.pan@neverland.mil> - 2016-03-17 17:46 +0100
                          Re: Exhausted "David Eather" <eather@tpg.com.au> - 2016-03-18 07:33 +1000
                      Re: Exhausted "David Eather" <eather@tpg.com.au> - 2016-03-18 07:35 +1000
                        Re: Exhausted Piotr Wyderski <peter.pan@neverland.mil> - 2016-03-18 11:44 +0100
        low-voltage low-current noise sources Winfield Hill <hill@rowland.harvard.edu> - 2016-03-16 08:10 -0700
    Re: Exhausted John Larkin <jjlarkin@highlandtechnology.com> - 2016-03-16 08:35 -0700
      Re: Exhausted "David Eather" <eather@tpg.com.au> - 2016-03-18 07:52 +1000
        Re: Exhausted John Larkin <jjlarkin@highlandtechnology.com> - 2016-03-17 15:35 -0700
          Re: Exhausted "David Eather" <eather@tpg.com.au> - 2016-03-18 09:09 +1000
            Re: Exhausted John Larkin <jjlarkin@highlandtechnology.com> - 2016-03-17 16:54 -0700
            Re: Exhausted George Herold <gherold@teachspin.com> - 2016-03-17 17:40 -0700
              Re: Exhausted mixed nuts <melopsitticus@undulatus.budgie> - 2016-03-17 22:37 -0400
          Re: Exhausted "David Eather" <eather@tpg.com.au> - 2016-03-18 09:09 +1000
          Re: Exhausted George Herold <gherold@teachspin.com> - 2016-03-17 17:29 -0700

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#403026 — Exhausted

If any kind soul can help...

There was a short post/note on SED or SEB about a transistor with a 2.5V  
max Vebo and another one with 3.0 max Vebo. I have spent hours looking for  
the transistors and have run out of options. Does anyone remember which  
transistor numbers these were?

I'm adding transistor junction breakdown noise to a Arduino and they would  
fit the bill perfectly - and cut out problem of providing extra voltage  
sources other than %v power from USB.

As always TIA.

[toc] | [next] | [standalone]

#403033

On Wednesday, March 16, 2016 at 6:53:11 AM UTC+1, David Eather wrote:
> If any kind soul can help...
> 
> There was a short post/note on SED or SEB about a transistor with a 2.5V  
> max Vebo and another one with 3.0 max Vebo. I have spent hours looking for  
> the transistors and have run out of options. Does anyone remember which  
> transistor numbers these were?
> 
> I'm adding transistor junction breakdown noise to a Arduino and they would  
> fit the bill perfectly - and cut out problem of providing extra voltage  
> sources other than %v power from USB.
> 
> As always TIA.

This one:

https://groups.google.com/forum/#!searchin/sci.electronics.design/vebo$203$202.5/sci.electronics.design/_CltveiGmEY/3YcRcP_4QUwJ

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#403051

On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather wrote:
> If any kind soul can help...
> 
> There was a short post/note on SED or SEB about a transistor with a 2.5V  
> max Vebo and another one with 3.0 max Vebo. I have spent hours looking for  
> the transistors and have run out of options. Does anyone remember which  
> transistor numbers these were?
> 
> I'm adding transistor junction breakdown noise to a Arduino and they would  
> fit the bill perfectly - and cut out problem of providing extra voltage  
> sources other than %v power from USB.
> 
> As always TIA.

I don't know the transistors, but have you tried a low voltage zener.  
(The problem with both is that you may not get much more than just the 
shot noise.)  

George H. 

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#403063

On Wed, 16 Mar 2016 23:04:13 +1000, George Herold <gherold@teachspin.com>  
wrote:

> On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather wrote:
>> If any kind soul can help...
>>
>> There was a short post/note on SED or SEB about a transistor with a 2.5V
>> max Vebo and another one with 3.0 max Vebo. I have spent hours looking  
>> for
>> the transistors and have run out of options. Does anyone remember which
>> transistor numbers these were?
>>
>> I'm adding transistor junction breakdown noise to a Arduino and they  
>> would
>> fit the bill perfectly - and cut out problem of providing extra voltage
>> sources other than %v power from USB.
>>
>> As always TIA.
>
> I don't know the transistors, but have you tried a low voltage zener.
> (The problem with both is that you may not get much more than just the
> shot noise.)
>
> George H.

Zener is OK but my experiments suggest noise is about an order of  
magnitude lower. On the plus side transistor junctions seem to 'age' and  
become quieter as time goes on. (both effects may be non-existent and just  
the result of my poor experiments)

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#403079

On Thu, 17 Mar 2016 00:16:22 +1000, David Eather wrote:

> On Wed, 16 Mar 2016 23:04:13 +1000, George Herold
> <gherold@teachspin.com> wrote:
> 
>> On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather wrote:
>>> If any kind soul can help...
>>>
>>> There was a short post/note on SED or SEB about a transistor with a
>>> 2.5V max Vebo and another one with 3.0 max Vebo. I have spent hours
>>> looking for the transistors and have run out of options. Does anyone
>>> remember which transistor numbers these were?
>>>
>>> I'm adding transistor junction breakdown noise to a Arduino and they
>>> would fit the bill perfectly - and cut out problem of providing extra
>>> voltage sources other than %v power from USB.
>>>
>>> As always TIA.
>>
>> I don't know the transistors, but have you tried a low voltage zener.
>> (The problem with both is that you may not get much more than just the
>> shot noise.)
>>
>> George H.
> 
> Zener is OK but my experiments suggest noise is about an order of
> magnitude lower. On the plus side transistor junctions seem to 'age' and
> become quieter as time goes on. (both effects may be non-existent and
> just the result of my poor experiments)


We had a reverse-biased BE junction noise generator in an old product 
fail after several years in the field.  The problem was that the 
statistical tests on the entropy source failed yet the DC measurements on 
the transistor seemed fine when a technician looked at it.  The stats 
came good once the part was changed for a new one.

I guess one shouldn't expect too much when using a device outside its 
abs. max. ratings.


Allan

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#403099

On Wednesday, March 16, 2016 at 12:37:34 PM UTC-4, Allan Herriman wrote:
> On Thu, 17 Mar 2016 00:16:22 +1000, David Eather wrote:
> 
> > On Wed, 16 Mar 2016 23:04:13 +1000, George Herold
> > <gherold@teachspin.com> wrote:
> > 
> >> On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather wrote:
> >>> If any kind soul can help...
> >>>
> >>> There was a short post/note on SED or SEB about a transistor with a
> >>> 2.5V max Vebo and another one with 3.0 max Vebo. I have spent hours
> >>> looking for the transistors and have run out of options. Does anyone
> >>> remember which transistor numbers these were?
> >>>
> >>> I'm adding transistor junction breakdown noise to a Arduino and they
> >>> would fit the bill perfectly - and cut out problem of providing extra
> >>> voltage sources other than %v power from USB.
> >>>
> >>> As always TIA.
> >>
> >> I don't know the transistors, but have you tried a low voltage zener.
> >> (The problem with both is that you may not get much more than just the
> >> shot noise.)
> >>
> >> George H.
> > 
> > Zener is OK but my experiments suggest noise is about an order of
> > magnitude lower. On the plus side transistor junctions seem to 'age' and
> > become quieter as time goes on. (both effects may be non-existent and
> > just the result of my poor experiments)
> 
> 
> We had a reverse-biased BE junction noise generator in an old product 
> fail after several years in the field.  The problem was that the 
> statistical tests on the entropy source failed yet the DC measurements on 
> the transistor seemed fine when a technician looked at it.  The stats 
> came good once the part was changed for a new one.
> 
> I guess one shouldn't expect too much when using a device outside its 
> abs. max. ratings.
Hmm I wonder if an avalanche zener would have been better, at least they
are made to break down all day.  I guess if you needed speed 
(higher noise bandwidth) that the capacitance of the zener might have been a problem.

George H. 
  
> 
> 
> Allan

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#403213

On Wed, 16 Mar 2016 11:15:20 -0700, George Herold wrote:

> On Wednesday, March 16, 2016 at 12:37:34 PM UTC-4, Allan Herriman wrote:
>> On Thu, 17 Mar 2016 00:16:22 +1000, David Eather wrote:
>> 
>> > On Wed, 16 Mar 2016 23:04:13 +1000, George Herold
>> > <gherold@teachspin.com> wrote:
>> > 
>> >> On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather
>> >> wrote:
>> >>> If any kind soul can help...
>> >>>
>> >>> There was a short post/note on SED or SEB about a transistor with a
>> >>> 2.5V max Vebo and another one with 3.0 max Vebo. I have spent hours
>> >>> looking for the transistors and have run out of options. Does
>> >>> anyone remember which transistor numbers these were?
>> >>>
>> >>> I'm adding transistor junction breakdown noise to a Arduino and
>> >>> they would fit the bill perfectly - and cut out problem of
>> >>> providing extra voltage sources other than %v power from USB.
>> >>>
>> >>> As always TIA.
>> >>
>> >> I don't know the transistors, but have you tried a low voltage
>> >> zener. (The problem with both is that you may not get much more than
>> >> just the shot noise.)
>> >>
>> >> George H.
>> > 
>> > Zener is OK but my experiments suggest noise is about an order of
>> > magnitude lower. On the plus side transistor junctions seem to 'age'
>> > and become quieter as time goes on. (both effects may be non-existent
>> > and just the result of my poor experiments)
>> 
>> 
>> We had a reverse-biased BE junction noise generator in an old product
>> fail after several years in the field.  The problem was that the
>> statistical tests on the entropy source failed yet the DC measurements
>> on the transistor seemed fine when a technician looked at it.  The
>> stats came good once the part was changed for a new one.
>> 
>> I guess one shouldn't expect too much when using a device outside its
>> abs. max. ratings.
> Hmm I wonder if an avalanche zener would have been better, at least they
> are made to break down all day.  I guess if you needed speed (higher
> noise bandwidth) that the capacitance of the zener might have been a
> problem.


The issue with real avalanche diodes is that they need a high voltage 
supply.  In something low voltage (e.g. single Li cell or USB powered) 
this requires a boost converter or charge pump.  Then you need to be 
careful to keep the switching noise out of the low amplitude "good" 
noise, assuming you haven't already ruled it out on the basis of board 
space or BOM cost.

Regards,
Allan

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#403246

On Wednesday, March 16, 2016 at 7:16:26 AM UTC-7, David Eather wrote:
> On Wed, 16 Mar 2016 23:04:13 +1000, George Herold <gherold@teachspin.com>  
> wrote:
> 
> > On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather wrote:
> >> If any kind soul can help...
> >>
> >> There was a short post/note on SED or SEB about a transistor with a 2.5V
> >> max Vebo and another one with 3.0 max Vebo. I have spent hours looking  
> >> for
> >> the transistors and have run out of options. Does anyone remember which
> >> transistor numbers these were?
> >>
> >> I'm adding transistor junction breakdown noise to a Arduino and they  
> >> would
> >> fit the bill perfectly - and cut out problem of providing extra voltage
> >> sources other than %v power from USB.
> >>
> >> As always TIA.
> >
> > I don't know the transistors, but have you tried a low voltage zener.
> > (The problem with both is that you may not get much more than just the
> > shot noise.)
> >
> > George H.
> 
> Zener is OK but my experiments suggest noise is about an order of  
> magnitude lower. On the plus side transistor junctions seem to 'age' and  
> become quieter as time goes on. (both effects may be non-existent and just  
> the result of my poor experiments)


(Beginner here)

Say, did you mean that transistors get quieter as they age?

(intrigued)

Michael

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#403264

On Fri, 18 Mar 2016 03:37:21 +1000, <mrdarrett@gmail.com> wrote:

> On Wednesday, March 16, 2016 at 7:16:26 AM UTC-7, David Eather wrote:
>> On Wed, 16 Mar 2016 23:04:13 +1000, George Herold  
>> <gherold@teachspin.com>
>> wrote:
>>
>> > On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather wrote:
>> >> If any kind soul can help...
>> >>
>> >> There was a short post/note on SED or SEB about a transistor with a  
>> 2.5V
>> >> max Vebo and another one with 3.0 max Vebo. I have spent hours  
>> looking
>> >> for
>> >> the transistors and have run out of options. Does anyone remember  
>> which
>> >> transistor numbers these were?
>> >>
>> >> I'm adding transistor junction breakdown noise to a Arduino and they
>> >> would
>> >> fit the bill perfectly - and cut out problem of providing extra  
>> voltage
>> >> sources other than %v power from USB.
>> >>
>> >> As always TIA.
>> >
>> > I don't know the transistors, but have you tried a low voltage zener.
>> > (The problem with both is that you may not get much more than just the
>> > shot noise.)
>> >
>> > George H.
>>
>> Zener is OK but my experiments suggest noise is about an order of
>> magnitude lower. On the plus side transistor junctions seem to 'age' and
>> become quieter as time goes on. (both effects may be non-existent and  
>> just
>> the result of my poor experiments)
>
>
> (Beginner here)
>
> Say, did you mean that transistors get quieter as they age?
>
> (intrigued)
>
> Michael

When you reverse bias the emitter to base junction enough it breaks down  
and produces lots of random electrical noise, but over time the amount of  
noise decreases and after a long time (many months or years) it may no  
longer produce enough noise to be useful. It also ruins the transistor for  
anything else.

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#403275

On Thursday, March 17, 2016 at 2:25:04 PM UTC-7, David Eather wrote:
> On Fri, 18 Mar 2016 03:37:21 +1000, <mrdarrett@gmail.com> wrote:
> 
> > On Wednesday, March 16, 2016 at 7:16:26 AM UTC-7, David Eather wrote:
> >> On Wed, 16 Mar 2016 23:04:13 +1000, George Herold  
> >> <gherold@teachspin.com>
> >> wrote:
> >>
> >> > On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather wrote:
> >> >> If any kind soul can help...
> >> >>
> >> >> There was a short post/note on SED or SEB about a transistor with a  
> >> 2.5V
> >> >> max Vebo and another one with 3.0 max Vebo. I have spent hours  
> >> looking
> >> >> for
> >> >> the transistors and have run out of options. Does anyone remember  
> >> which
> >> >> transistor numbers these were?
> >> >>
> >> >> I'm adding transistor junction breakdown noise to a Arduino and they
> >> >> would
> >> >> fit the bill perfectly - and cut out problem of providing extra  
> >> voltage
> >> >> sources other than %v power from USB.
> >> >>
> >> >> As always TIA.
> >> >
> >> > I don't know the transistors, but have you tried a low voltage zener.
> >> > (The problem with both is that you may not get much more than just the
> >> > shot noise.)
> >> >
> >> > George H.
> >>
> >> Zener is OK but my experiments suggest noise is about an order of
> >> magnitude lower. On the plus side transistor junctions seem to 'age' and
> >> become quieter as time goes on. (both effects may be non-existent and  
> >> just
> >> the result of my poor experiments)
> >
> >
> > (Beginner here)
> >
> > Say, did you mean that transistors get quieter as they age?
> >
> > (intrigued)
> >
> > Michael
> 
> When you reverse bias the emitter to base junction enough it breaks down  
> and produces lots of random electrical noise, but over time the amount of  
> noise decreases and after a long time (many months or years) it may no  
> longer produce enough noise to be useful. It also ruins the transistor for  
> anything else.


Oh!  Okay.  So much for the idea that over time, the transistor becomes better :p

Thanks for the clarification

Michael

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#403065

George Herold wrote...
>
>On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather wrote:
>> If any kind soul can help...
>> 
>> There was a short post/note on SED or SEB about a transistor with a 2.5V  
>> max Vebo and another one with 3.0 max Vebo. I have spent hours looking for  
>> the transistors and have run out of options. Does anyone remember which  
>> transistor numbers these were?
>> 
>> I'm adding transistor junction breakdown noise to a Arduino and they would  
>> fit the bill perfectly - and cut out problem of providing extra voltage  
>> sources other than %v power from USB.
>> 
>> As always TIA.
> 
> I don't know the transistors, but have you tried a low voltage zener.  
> (The problem with both is that you may not get much more than just the 
> shot noise.)  

 Agreed, the zener noise mechanism comes from avalanche, which
 doesn't kick in until you get to voltages above about 8 volts.
 Low-current "microplasmas" form and quickly terminate after
 discharging the zener's self capacitance, creating a kind of
 popcorn noise.   There are extensive threads on the subject
 15-20 years ago on s.e.d., where I spent a month (haha, more)
 making and posting all kinds of nanosecond-scale measurements.

 The zener physics effect (field emission) predominates at
 low-voltages, see the ON Semi handbook, HBD854, page 20. 
 https://www.onsemi.com/pub/Collateral/HBD854-D.PDF


-- 
 Thanks,
    - Win

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#403067

On Wednesday, March 16, 2016 at 10:33:03 AM UTC-4, Winfield Hill wrote:
> George Herold wrote...
> >
> >On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather wrote:
> >> If any kind soul can help...
> >> 
> >> There was a short post/note on SED or SEB about a transistor with a 2.5V  
> >> max Vebo and another one with 3.0 max Vebo. I have spent hours looking for  
> >> the transistors and have run out of options. Does anyone remember which  
> >> transistor numbers these were?
> >> 
> >> I'm adding transistor junction breakdown noise to a Arduino and they would  
> >> fit the bill perfectly - and cut out problem of providing extra voltage  
> >> sources other than %v power from USB.
> >> 
> >> As always TIA.
> > 
> > I don't know the transistors, but have you tried a low voltage zener.  
> > (The problem with both is that you may not get much more than just the 
> > shot noise.)  
> 
>  Agreed, the zener noise mechanism comes from avalanche, which
>  doesn't kick in until you get to voltages above about 8 volts.
>  Low-current "microplasmas" form and quickly terminate after
>  discharging the zener's self capacitance, creating a kind of
>  popcorn noise.   There are extensive threads on the subject
>  15-20 years ago on s.e.d., where I spent a month (haha, more)
>  making and posting all kinds of nanosecond-scale measurements.
> 
>  The zener physics effect (field emission) predominates at
>  low-voltages, see the ON Semi handbook, HBD854, page 20. 
>  https://www.onsemi.com/pub/Collateral/HBD854-D.PDF
> 
> 
> -- 
>  Thanks,
>     - Win

Grin.. everyone should spend a month playing with avalanche breakdown.  

Say Win, If you want to "waste" a few more hours with avalanches, 
I can send you some LED's that breakdown ~25 Volts and are 
single photon detectors. (Spad's)  They make great little experiments 
for electronics courses.  (perhaps Paul would be more interested?)  
These.. you can also get them from Newark.
http://www.purdyelectronics.com/pdf/AND113R.pdf

A newsletter.
http://nebula.wsimg.com/0b846f1e91ab9c7442a61c8c35680a51?AccessKeyId=027C3581808C75E81679&disposition=0&alloworigin=1

George H. 
   

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#403071

George Herold wrote...
>
>On Wednesday, March 16, 2016 at 10:33:03 AM UTC-4, Winfield Hill wrote:
>> George Herold wrote...
>> >
>> >On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather wrote:
>> >> If any kind soul can help...
>> >> 
>> >> There was a short post/note on SED or SEB about a transistor with a 2.5V  
>>>> max Vebo and another one with 3.0 max Vebo. I have spent hours looking for
>> >> the transistors and have run out of options. Does anyone remember which  
>> >> transistor numbers these were?
>> >> 
>>>> I'm adding transistor junction breakdown noise to a Arduino and they would
>> >> fit the bill perfectly - and cut out problem of providing extra voltage  
>> >> sources other than %v power from USB.
>> >> 
>> >> As always TIA.
>> > 
>> > I don't know the transistors, but have you tried a low voltage zener.  
>> > (The problem with both is that you may not get much more than just the 
>> > shot noise.)  
>> 
>>  Agreed, the zener noise mechanism comes from avalanche, which
>>  doesn't kick in until you get to voltages above about 8 volts.
>>  Low-current "microplasmas" form and quickly terminate after
>>  discharging the zener's self capacitance, creating a kind of
>>  popcorn noise.   There are extensive threads on the subject
>>  15-20 years ago on s.e.d., where I spent a month (haha, more)
>>  making and posting all kinds of nanosecond-scale measurements.
>> 
>>  The zener physics effect (field emission) predominates at
>>  low-voltages, see the ON Semi handbook, HBD854, page 20. 
>>  https://www.onsemi.com/pub/Collateral/HBD854-D.PDF
>> 
>> 
>> -- 
>>  Thanks,
>>     - Win
>
>Grin.. everyone should spend a month playing with avalanche breakdown.  
>
>Say Win, If you want to "waste" a few more hours with avalanches, 
>I can send you some LED's that breakdown ~25 Volts and are 
>single photon detectors. (Spad's)  They make great little experiments 
>for electronics courses.  (perhaps Paul would be more interested?)  
>These.. you can also get them from Newark.
>http://www.purdyelectronics.com/pdf/AND113R.pdf
>
>A newsletter.
>http://nebula.wsimg.com/0b846f1e91ab9c7442a61c8c35680a51?AccessKeyId=027C3581808C75E81679&disposition=0&alloworigin=1
>
>George H.    

 Awesome!


-- 
 Thanks,
    - Win

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#403091

On Wed, 16 Mar 2016 08:04:34 -0700 (PDT), George Herold
<gherold@teachspin.com> wrote:

>On Wednesday, March 16, 2016 at 10:33:03 AM UTC-4, Winfield Hill wrote:
>> George Herold wrote...
>> >
>> >On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather wrote:
>> >> If any kind soul can help...
>> >> 
>> >> There was a short post/note on SED or SEB about a transistor with a 2.5V  
>> >> max Vebo and another one with 3.0 max Vebo. I have spent hours looking for  
>> >> the transistors and have run out of options. Does anyone remember which  
>> >> transistor numbers these were?
>> >> 
>> >> I'm adding transistor junction breakdown noise to a Arduino and they would  
>> >> fit the bill perfectly - and cut out problem of providing extra voltage  
>> >> sources other than %v power from USB.
>> >> 
>> >> As always TIA.
>> > 
>> > I don't know the transistors, but have you tried a low voltage zener.  
>> > (The problem with both is that you may not get much more than just the 
>> > shot noise.)  
>> 
>>  Agreed, the zener noise mechanism comes from avalanche, which
>>  doesn't kick in until you get to voltages above about 8 volts.
>>  Low-current "microplasmas" form and quickly terminate after
>>  discharging the zener's self capacitance, creating a kind of
>>  popcorn noise.   There are extensive threads on the subject
>>  15-20 years ago on s.e.d., where I spent a month (haha, more)
>>  making and posting all kinds of nanosecond-scale measurements.
>> 
>>  The zener physics effect (field emission) predominates at
>>  low-voltages, see the ON Semi handbook, HBD854, page 20. 
>>  https://www.onsemi.com/pub/Collateral/HBD854-D.PDF
>> 
>> 
>> -- 
>>  Thanks,
>>     - Win
>
>Grin.. everyone should spend a month playing with avalanche breakdown.  
>
>Say Win, If you want to "waste" a few more hours with avalanches, 
>I can send you some LED's that breakdown ~25 Volts and are 
>single photon detectors. (Spad's)  They make great little experiments 
>for electronics courses.  (perhaps Paul would be more interested?)  
>These.. you can also get them from Newark.
>http://www.purdyelectronics.com/pdf/AND113R.pdf
>
>A newsletter.
>http://nebula.wsimg.com/0b846f1e91ab9c7442a61c8c35680a51?AccessKeyId=027C3581808C75E81679&disposition=0&alloworigin=1
>
>George H. 
>   

They would make a pretty good noise seed, probably even in the dark.


-- 

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement 

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

[toc] | [prev] | [next] | [standalone]

#403095

On Wednesday, March 16, 2016 at 1:32:54 PM UTC-4, John Larkin wrote:
> On Wed, 16 Mar 2016 08:04:34 -0700 (PDT), George Herold
> <gherold@teachspin.com> wrote:
> 
> >On Wednesday, March 16, 2016 at 10:33:03 AM UTC-4, Winfield Hill wrote:
> >> George Herold wrote...
> >> >
> >> >On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather wrote:
> >> >> If any kind soul can help...
> >> >> 
> >> >> There was a short post/note on SED or SEB about a transistor with a 2.5V  
> >> >> max Vebo and another one with 3.0 max Vebo. I have spent hours looking for  
> >> >> the transistors and have run out of options. Does anyone remember which  
> >> >> transistor numbers these were?
> >> >> 
> >> >> I'm adding transistor junction breakdown noise to a Arduino and they would  
> >> >> fit the bill perfectly - and cut out problem of providing extra voltage  
> >> >> sources other than %v power from USB.
> >> >> 
> >> >> As always TIA.
> >> > 
> >> > I don't know the transistors, but have you tried a low voltage zener.  
> >> > (The problem with both is that you may not get much more than just the 
> >> > shot noise.)  
> >> 
> >>  Agreed, the zener noise mechanism comes from avalanche, which
> >>  doesn't kick in until you get to voltages above about 8 volts.
> >>  Low-current "microplasmas" form and quickly terminate after
> >>  discharging the zener's self capacitance, creating a kind of
> >>  popcorn noise.   There are extensive threads on the subject
> >>  15-20 years ago on s.e.d., where I spent a month (haha, more)
> >>  making and posting all kinds of nanosecond-scale measurements.
> >> 
> >>  The zener physics effect (field emission) predominates at
> >>  low-voltages, see the ON Semi handbook, HBD854, page 20. 
> >>  https://www.onsemi.com/pub/Collateral/HBD854-D.PDF
> >> 
> >> 
> >> -- 
> >>  Thanks,
> >>     - Win
> >
> >Grin.. everyone should spend a month playing with avalanche breakdown.  
> >
> >Say Win, If you want to "waste" a few more hours with avalanches, 
> >I can send you some LED's that breakdown ~25 Volts and are 
> >single photon detectors. (Spad's)  They make great little experiments 
> >for electronics courses.  (perhaps Paul would be more interested?)  
> >These.. you can also get them from Newark.
> >http://www.purdyelectronics.com/pdf/AND113R.pdf
> >
> >A newsletter.
> >http://nebula.wsimg.com/0b846f1e91ab9c7442a61c8c35680a51?AccessKeyId=027C3581808C75E81679&disposition=0&alloworigin=1
> >
> >George H. 
> >   
> 
> They would make a pretty good noise seed, probably even in the dark.

Well maybe, probably not in the dark.  About 10-20% of them show  a lot 
of after pulsing... breaking down almost all the time even in the dark.
 (After the channel breaks down, there are dangling 
charges left around and those can cause it to break down again.)  
So there is not a random distribution of pulses, but a large chance of 
having another pulse soon after one has happened.   That shows up in the 
statistics.. you get a kinda 1/f distribution of times and not the expected 
exponential.  

George H. 
> 
> 
> -- 
> 
> John Larkin         Highland Technology, Inc
> picosecond timing   precision measurement 
> 
> jlarkin att highlandtechnology dott com
> http://www.highlandtechnology.com

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#403115

On Wed, 16 Mar 2016 11:08:27 -0700 (PDT), George Herold
<gherold@teachspin.com> wrote:

>On Wednesday, March 16, 2016 at 1:32:54 PM UTC-4, John Larkin wrote:
>> On Wed, 16 Mar 2016 08:04:34 -0700 (PDT), George Herold
>> <gherold@teachspin.com> wrote:
>> 
>> >On Wednesday, March 16, 2016 at 10:33:03 AM UTC-4, Winfield Hill wrote:
>> >> George Herold wrote...
>> >> >
>> >> >On Wednesday, March 16, 2016 at 1:53:11 AM UTC-4, David Eather wrote:
>> >> >> If any kind soul can help...
>> >> >> 
>> >> >> There was a short post/note on SED or SEB about a transistor with a 2.5V  
>> >> >> max Vebo and another one with 3.0 max Vebo. I have spent hours looking for  
>> >> >> the transistors and have run out of options. Does anyone remember which  
>> >> >> transistor numbers these were?
>> >> >> 
>> >> >> I'm adding transistor junction breakdown noise to a Arduino and they would  
>> >> >> fit the bill perfectly - and cut out problem of providing extra voltage  
>> >> >> sources other than %v power from USB.
>> >> >> 
>> >> >> As always TIA.
>> >> > 
>> >> > I don't know the transistors, but have you tried a low voltage zener.  
>> >> > (The problem with both is that you may not get much more than just the 
>> >> > shot noise.)  
>> >> 
>> >>  Agreed, the zener noise mechanism comes from avalanche, which
>> >>  doesn't kick in until you get to voltages above about 8 volts.
>> >>  Low-current "microplasmas" form and quickly terminate after
>> >>  discharging the zener's self capacitance, creating a kind of
>> >>  popcorn noise.   There are extensive threads on the subject
>> >>  15-20 years ago on s.e.d., where I spent a month (haha, more)
>> >>  making and posting all kinds of nanosecond-scale measurements.
>> >> 
>> >>  The zener physics effect (field emission) predominates at
>> >>  low-voltages, see the ON Semi handbook, HBD854, page 20. 
>> >>  https://www.onsemi.com/pub/Collateral/HBD854-D.PDF
>> >> 
>> >> 
>> >> -- 
>> >>  Thanks,
>> >>     - Win
>> >
>> >Grin.. everyone should spend a month playing with avalanche breakdown.  
>> >
>> >Say Win, If you want to "waste" a few more hours with avalanches, 
>> >I can send you some LED's that breakdown ~25 Volts and are 
>> >single photon detectors. (Spad's)  They make great little experiments 
>> >for electronics courses.  (perhaps Paul would be more interested?)  
>> >These.. you can also get them from Newark.
>> >http://www.purdyelectronics.com/pdf/AND113R.pdf
>> >
>> >A newsletter.
>> >http://nebula.wsimg.com/0b846f1e91ab9c7442a61c8c35680a51?AccessKeyId=027C3581808C75E81679&disposition=0&alloworigin=1
>> >
>> >George H. 
>> >   
>> 
>> They would make a pretty good noise seed, probably even in the dark.
>
>Well maybe, probably not in the dark.  About 10-20% of them show  a lot 
>of after pulsing... breaking down almost all the time even in the dark.
> (After the channel breaks down, there are dangling 
>charges left around and those can cause it to break down again.)  
>So there is not a random distribution of pulses, but a large chance of 
>having another pulse soon after one has happened.   That shows up in the 
>statistics.. you get a kinda 1/f distribution of times and not the expected 
>exponential.  
>
>George H. 
>> 
>> 
>> -- 
>> 
>> John Larkin         Highland Technology, Inc
>> picosecond timing   precision measurement 
>> 
>> jlarkin att highlandtechnology dott com
>> http://www.highlandtechnology.com

A random number seeder needs to be random but need not have good
statistics. But once you have that much voltage available, you may as
well use a zener.

An opamp with a lot of closed-loop gain will generate a ton of noise,
with an awful 1/f type spectrum, but again that can be a fine
random-number seed, used to scramble/hash some deterministic
pseudo-random thing.

Good flat analog noise is best derived from a linear shift register,
or from a zener, or both. It's easy to make a pseudo-random shift
register thing that won't repeat for a thousand years.

Some uPs include a mess of ring oscillators to generate random
numbers; we were just talking about that, specifically the temperature
coefficient of ring oscillators inside an FPGA. 

https://dl.dropboxusercontent.com/u/53724080/Thermal/ESM_Ring_Oscillator.jpg



-- 

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement 

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

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#403147

On 17/03/16 06:30, John Larkin wrote:
> On Wed, 16 Mar 2016 11:08:27 -0700 (PDT), George Herold
> <gherold@teachspin.com> wrote:
>
>> On Wednesday, March 16, 2016 at 1:32:54 PM UTC-4, John Larkin wrote:
>>> They would make a pretty good noise seed, probably even in the dark.
>> Well maybe, probably not in the dark.  About 10-20% of them show  a lot
>> of after pulsing... breaking down almost all the time even in the dark.
>> (After the channel breaks down, there are dangling
>> charges left around and those can cause it to break down again.)
>> So there is not a random distribution of pulses, but a large chance of
>> having another pulse soon after one has happened.   That shows up in the
>> statistics.. you get a kinda 1/f distribution of times and not the expected
>> exponential.
> A random number seeder needs to be random but need not have good
> statistics. But once you have that much voltage available, you may as
> well use a zener.
>
> An opamp with a lot of closed-loop gain will generate a ton of noise,
> with an awful 1/f type spectrum, but again that can be a fine
> random-number seed, used to scramble/hash some deterministic
> pseudo-random thing.

I used the shorted microphone input of a cheap sound-card (at full 
volume) to get random bits to stir into the 64kbit entropy pool in one 
of Europe's first Internet banking applications (SSL, but 1997, before 
web browsers were really usable for this).

2-3 random bits per sample out of 16, so 8K stereo samples produced a 
very fair amount of entropy - we were only tapping the pool for a few 
hundred bits once for each new connection. With 100k users connecting on 
average a few times per week, almost overkill.

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#403150

On Thu, 17 Mar 2016 06:47:09 +1100, Clifford Heath
<no.spam@please.net> wrote:

>On 17/03/16 06:30, John Larkin wrote:
>> On Wed, 16 Mar 2016 11:08:27 -0700 (PDT), George Herold
>> <gherold@teachspin.com> wrote:
>>
>>> On Wednesday, March 16, 2016 at 1:32:54 PM UTC-4, John Larkin wrote:
>>>> They would make a pretty good noise seed, probably even in the dark.
>>> Well maybe, probably not in the dark.  About 10-20% of them show  a lot
>>> of after pulsing... breaking down almost all the time even in the dark.
>>> (After the channel breaks down, there are dangling
>>> charges left around and those can cause it to break down again.)
>>> So there is not a random distribution of pulses, but a large chance of
>>> having another pulse soon after one has happened.   That shows up in the
>>> statistics.. you get a kinda 1/f distribution of times and not the expected
>>> exponential.
>> A random number seeder needs to be random but need not have good
>> statistics. But once you have that much voltage available, you may as
>> well use a zener.
>>
>> An opamp with a lot of closed-loop gain will generate a ton of noise,
>> with an awful 1/f type spectrum, but again that can be a fine
>> random-number seed, used to scramble/hash some deterministic
>> pseudo-random thing.
>
>I used the shorted microphone input of a cheap sound-card (at full 
>volume) to get random bits to stir into the 64kbit entropy pool in one 
>of Europe's first Internet banking applications (SSL, but 1997, before 
>web browsers were really usable for this).
>
>2-3 random bits per sample out of 16, so 8K stereo samples produced a 
>very fair amount of entropy - we were only tapping the pool for a few 
>hundred bits once for each new connection. With 100k users connecting on 
>average a few times per week, almost overkill.

I wonder if there is a public random data generator somewhere on the
internet. You could use ping times or something as a source of
randomness.

Any online webcam should provide a lot of noise.



-- 

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement 

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

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#403151

On 17/03/16 11:01, John Larkin wrote:
> On Thu, 17 Mar 2016 06:47:09 +1100, Clifford Heath
> <no.spam@please.net> wrote:
>> I used the shorted microphone input of a cheap sound-card (at full
>> volume) to get random bits to stir into the 64kbit entropy pool in one
>> of Europe's first Internet banking applications (SSL, but 1997, before
>> web browsers were really usable for this).
>>
>> 2-3 random bits per sample out of 16, so 8K stereo samples produced a
>> very fair amount of entropy - we were only tapping the pool for a few
>> hundred bits once for each new connection. With 100k users connecting on
>> average a few times per week, almost overkill.
>
> I wonder if there is a public random data generator somewhere on the
> internet. You could use ping times or something as a source of
> randomness.

Actually, for strong security, the goal isn't actually randomness, it's 
unpredictability. Doesn't matter much what data you use, as long as the 
bad guys can't guess it.

Using an online source would be terribly, terribly stupid.

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#403154

On Thu, 17 Mar 2016 07:01:57 +1100, Clifford Heath
<no.spam@please.net> wrote:

>On 17/03/16 11:01, John Larkin wrote:
>> On Thu, 17 Mar 2016 06:47:09 +1100, Clifford Heath
>> <no.spam@please.net> wrote:
>>> I used the shorted microphone input of a cheap sound-card (at full
>>> volume) to get random bits to stir into the 64kbit entropy pool in one
>>> of Europe's first Internet banking applications (SSL, but 1997, before
>>> web browsers were really usable for this).
>>>
>>> 2-3 random bits per sample out of 16, so 8K stereo samples produced a
>>> very fair amount of entropy - we were only tapping the pool for a few
>>> hundred bits once for each new connection. With 100k users connecting on
>>> average a few times per week, almost overkill.
>>
>> I wonder if there is a public random data generator somewhere on the
>> internet. You could use ping times or something as a source of
>> randomness.
>
>Actually, for strong security, the goal isn't actually randomness, it's 
>unpredictability. Doesn't matter much what data you use, as long as the 
>bad guys can't guess it.
>
>Using an online source would be terribly, terribly stupid.

Well, you would certainly use it to seed some other, private random
number generator, not just as-received. And a web site could certainly
serve up a different block of bits to every request.




-- 

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement 

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

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