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Power with 20V


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#21 ziggurat29

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Posted 25 May 2013 - 12:59 PM

...Quite unsurpricingly but at the same time fascinating when you think of it and really ask your self "but why exactly?". I guess its a force of nature really. What we did was creating a histogram which is pretty much the Fourier transform, basically saying that any signal (stochastical or otherwise) can be broken down to a number (possibly infinite as in the case of square waves) of sinusoidals. In our case, I guess the "sinusoidals" were stochastical signals, simultainiously strectching in all possible directions but projected onto a vector in a six dimensional universe - the dice ;-)...

 

Fascinating point indeed; I never thought of a histogram as a Fourier transform, but then I'm an engineer rather than a mathematician...  Of course the histogram shows only the magnitude, so I suspect the randomness gets squeezed into the (not-depicted) phase component of the transform.

 

Some interesting reading on the NIST's standards for RNG;

http://csrc.nist.gov...800-22rev1a.pdf

(gasp!) Christmas came early this year!  Thanks, I actually needed a reviewed and accepted entropy measurement methodology recently -- I don't know why I didn't think of going to NIST at the time....

 

Well let us know how your noise generate works, and most importantly, how it's sequences test out.  Cutlass' zener mention makes me wonder if you could use a 3v zener and an appropriate amp and feed it into an a/d pin and get an acceptable similar noise result.  Then again I suspect part of all this circuitry is that the components (zener/transistor) aren't designed to be noisy, they're designed to be quiet, and so the gains needed might cause the amps to saturate on non-random ambient signals picked up, but maybe my concerns in that regard are unfounded.



#22 nakchak

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Posted 26 May 2013 - 08:41 AM

Have a look at eevblog.com Dave has just posted a couple of vids on voltage multipliers, might be a good start for getting the voltages youwant... Nak.

#23 ziggurat29

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Posted 30 May 2013 - 10:23 PM

off the topic of 20V, but on the topic of the RNG, I did get an interop assembly produced that enables access to the RNG hardware (amonst other things -- it's not specific to the RNG), and I am set to create a wiki article on the process, but....

 

The wiki won't let me log in to edit.  I was able to in Jan, but not today, alas.



#24 ziggurat29

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Posted 01 June 2013 - 02:51 PM

OK, in lieu of the wiki, I posted the info in a separate thread (about interops).  For the sample application, I read the on-chip hardware RNG.

q.v.

http://forums.netdui...-netmf/?p=50172

Maybe it will be of some use.



#25 Chris Walker

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Posted 04 June 2013 - 08:24 PM

On the topic of 20V... :) Netduino gen1 boards are rated for 7.5-12.0V. Netduino gen2 boards are rated for 7.5-9.0V; they are also compatible with a 12V regulated power supply but your efficiency and maximum output power may suffer. I would avoid 20V. That's too much voltage. A step-down regulator or switching power regulator can bring that down to the ~9V range, and then you're good to go. We love Netduinos and we'd hate to see yours get burned up :) Chris




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