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Geiger Counter / Horowitz Art of Electronics — Parallax Forums

Geiger Counter / Horowitz Art of Electronics

ArchiverArchiver Posts: 46,084
edited 2002-06-09 11:23 in General Discussion
Thanks for the info. I was looking for something less
likely to repeat after seeing your earlier post.
(After I wrote this I saw ad with a reprint of the
Dilbert cartoon where a troll is introduced as the
budget group's "random number generator" and
repeatedly chants "NINE NINE NINE..."; "That's the
problem with randomness," says the troll who is
guiding Dilbert, "you can never be certain.")

As for ART OF ELECTRONICS by Horowitz and Hill, it
just came up twice in the PNP vs. NPN discussion, and
as Tom S pointed out that Bookpool.com has it for
$50.50. I just bought it at Borders this week with a
20% coupon they mailed me (sometimes it does pay to
get put on mailing lists), although apart from taxes
it would have been a few cents cheaper at Bookpool
using 3- or 4-day ground shipping. No one else seems
to discount it nearly so much (except used). If only
Bookpool carried all of my textbooks.

Regards

Bob Pence



--- "Dennis P. O'Leary" <doleary@h...> wrote:
> If your goal is random number generation, I'd
> recommend using software
> instead of the hardware complexity of a radioactive
> source, Geiger
> counter, and adjusting for 'dead time' of
> Poisson-distributed Geiger
> pulses. Repeating myself ...
> --- Sent to basicstamps on 4/27/02 ---
> A software Pseudo Random Binary Sequence (PRBS)
> generator of N bits can
> be programmed to produce a series of random numbers
> that repeats only
> after 2^N-1 numbers. It works by XORing certain
> bits and feeding back
> the results to a software shift register. The
> entire generator is a
> byte, word, or multiple words, for greater length,
> so this is an
> efficient program for a Stamp. I've used this
> approach on many machines
> to generate psuedorandom noise. For a really long
> sequence, 3 32-bit
> sequences can be used together to produce a
> nonrepeating sequence that
> repeats after 2^94 numbers. That's a long sequence.
> The universe is
> <less than> 2^49 seconds old.
> --- End of repeated section ---
> Information on PRBS generation is found in Horowitz
> & Hill, "The Art of
> Electronics", 2nd Ed, Cambridge U Press, New York,
> 1989, among other
> sources.
>
> Dennis
>
> (Former nuclear physics grad student before
> switching to biophysics
> decades ago.)
>
>
Original Message
> From: Pence Bob [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=TK7_D8A-ka-QnIcd34TIj3ylGpm2hD5hEujiRcTRvDD_U7x5VGEJu_LE4JZEY4WrirG-dlK8UurrujK9elEs9A]bobpence_2000@y...[/url
> Sent: Friday, June 07, 2002 8:50 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Geiger Counter for random
> numbers
>
>
> I've read in several places about using input from a
> Geiger Counter for random number generation.
> However,
> I haven't seen any Geiger Counters priced in the
> hobbyist range. (I do controls engineering for a
> living, but my company's customers would probably be
> concerned if there was a Geiger Counter on our
> equipment). Where can I get a cheap Geiger Counter
> (or
> a worse sense of timing)?
>
> Bob Pence
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! - Official partner of 2002 FIFA World Cup
> http://fifaworldcup.yahoo.com
>
> To UNSUBSCRIBE, just send mail to:
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> from the same email address that you subscribed.
> Text in the Subject
> and Body of the message will be ignored.
>
>
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> http://docs.yahoo.com/info/terms/
>
>
>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed.
> Text in the Subject and Body of the message will be
> ignored.
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>


=====
Regards,

Bob Pence

NOTE: This mail is sent using my wireless phone. Calling me at 1 (610) 563-6198
is preferred to a reply. If replying to this email address, please do not quote
the original message.

__________________________________________________
Do You Yahoo!?
Yahoo! - Official partner of 2002 FIFA World Cup
http://fifaworldcup.yahoo.com

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2002-06-08 22:41
    Bob,

    Dilbert's troll provides a cool example from Shannon & Weaver's
    Information Theory of a channel that transmits no information, in the
    sense of p*log(p), because the message is always the same, and therefore
    known.

    Dennis

    Original Message
    From: Pence Bob [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=rwmNpnq-2JyN9GKEmxnDpcdWsRn_8I29YRrXiepLoJuAb5snffNxtDU0CI9dLJ-RRmhlSxC2tJH4DYfo1G1jVIaU]bobpence_2000@y...[/url
    Sent: Saturday, June 08, 2002 1:39 PM
    To: basicstamps@yahoogroups.com
    Subject: RE: [noparse][[/noparse]basicstamps] Geiger Counter / Horowitz Art of Electronics


    Thanks for the info. I was looking for something less
    likely to repeat after seeing your earlier post.
    (After I wrote this I saw ad with a reprint of the
    Dilbert cartoon where a troll is introduced as the
    budget group's "random number generator" and
    repeatedly chants "NINE NINE NINE..."; "That's the
    problem with randomness," says the troll who is
    guiding Dilbert, "you can never be certain.")

    As for ART OF ELECTRONICS by Horowitz and Hill, it
    just came up twice in the PNP vs. NPN discussion, and
    as Tom S pointed out that Bookpool.com has it for
    $50.50. I just bought it at Borders this week with a
    20% coupon they mailed me (sometimes it does pay to
    get put on mailing lists), although apart from taxes
    it would have been a few cents cheaper at Bookpool
    using 3- or 4-day ground shipping. No one else seems
    to discount it nearly so much (except used). If only
    Bookpool carried all of my textbooks.

    Regards

    Bob Pence

    <deleted>
  • ArchiverArchiver Posts: 46,084
    edited 2002-06-09 11:23
    Bob,

    One other option is to pulse count from a noisy diode, like a shottky diode.
    It will probably be cheaper than a geiger counter, but I think you'll have
    to do a little research and experimentation. See the notes on pulse
    stretching below.

    Another lower-cost method would be to use a diode to demodulate random rf
    signals from an antenna (basically a crystal set without the tuned cct) and
    amplify the signals up to 5v. The pulses might be a bit too fast for the
    stamp, so you might need a pre-scaler to divide the pulse train by say 1000.

    Regards,

    Tony

    Original Message
    From: "Pence Bob" <bobpence_2000@y...>
    To: <basicstamps@yahoogroups.com>
    Sent: Saturday, June 08, 2002 9:38 PM
    Subject: RE: [noparse][[/noparse]basicstamps] Geiger Counter / Horowitz Art of Electronics


    > Thanks for the info. I was looking for something less
    > likely to repeat after seeing your earlier post.
    > (After I wrote this I saw ad with a reprint of the
    > Dilbert cartoon where a troll is introduced as the
    > budget group's "random number generator" and
    > repeatedly chants "NINE NINE NINE..."; "That's the
    > problem with randomness," says the troll who is
    > guiding Dilbert, "you can never be certain.")
    >
    > As for ART OF ELECTRONICS by Horowitz and Hill, it
    > just came up twice in the PNP vs. NPN discussion, and
    > as Tom S pointed out that Bookpool.com has it for
    > $50.50. I just bought it at Borders this week with a
    > 20% coupon they mailed me (sometimes it does pay to
    > get put on mailing lists), although apart from taxes
    > it would have been a few cents cheaper at Bookpool
    > using 3- or 4-day ground shipping. No one else seems
    > to discount it nearly so much (except used). If only
    > Bookpool carried all of my textbooks.
    >
    > Regards
    >
    > Bob Pence
    >
    >
    >
    > --- "Dennis P. O'Leary" <doleary@h...> wrote:
    > > If your goal is random number generation, I'd
    > > recommend using software
    > > instead of the hardware complexity of a radioactive
    > > source, Geiger
    > > counter, and adjusting for 'dead time' of
    > > Poisson-distributed Geiger
    > > pulses. Repeating myself ...
    > > --- Sent to basicstamps on 4/27/02 ---
    > > A software Pseudo Random Binary Sequence (PRBS)
    > > generator of N bits can
    > > be programmed to produce a series of random numbers
    > > that repeats only
    > > after 2^N-1 numbers. It works by XORing certain
    > > bits and feeding back
    > > the results to a software shift register. The
    > > entire generator is a
    > > byte, word, or multiple words, for greater length,
    > > so this is an
    > > efficient program for a Stamp. I've used this
    > > approach on many machines
    > > to generate psuedorandom noise. For a really long
    > > sequence, 3 32-bit
    > > sequences can be used together to produce a
    > > nonrepeating sequence that
    > > repeats after 2^94 numbers. That's a long sequence.
    > > The universe is
    > > <less than> 2^49 seconds old.
    > > --- End of repeated section ---
    > > Information on PRBS generation is found in Horowitz
    > > & Hill, "The Art of
    > > Electronics", 2nd Ed, Cambridge U Press, New York,
    > > 1989, among other
    > > sources.
    > >
    > > Dennis
    > >
    > > (Former nuclear physics grad student before
    > > switching to biophysics
    > > decades ago.)
    > >
    > >
    Original Message
    > > From: Pence Bob [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=WzwwghzOwu73HbFRy53v02buZn23_ZUqWuid-6xc-H3t2-WfG39uB1HAbrGLYy3CWu-NCrCrl4JbEXWqC6Sz]bobpence_2000@y...[/url
    > > Sent: Friday, June 07, 2002 8:50 AM
    > > To: basicstamps@yahoogroups.com
    > > Subject: [noparse][[/noparse]basicstamps] Geiger Counter for random
    > > numbers
    > >
    > >
    > > I've read in several places about using input from a
    > > Geiger Counter for random number generation.
    > > However,
    > > I haven't seen any Geiger Counters priced in the
    > > hobbyist range. (I do controls engineering for a
    > > living, but my company's customers would probably be
    > > concerned if there was a Geiger Counter on our
    > > equipment). Where can I get a cheap Geiger Counter
    > > (or
    > > a worse sense of timing)?
    > >
    > > Bob Pence
    > >
    > > __________________________________________________
    > > Do You Yahoo!?
    > > Yahoo! - Official partner of 2002 FIFA World Cup
    > > http://fifaworldcup.yahoo.com
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > > from the same email address that you subscribed.
    > > Text in the Subject
    > > and Body of the message will be ignored.
    > >
    > >
    > > Your use of Yahoo! Groups is subject to
    > > http://docs.yahoo.com/info/terms/
    > >
    > >
    > >
    > >
    > >
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > > from the same email address that you subscribed.
    > > Text in the Subject and Body of the message will be
    > > ignored.
    > >
    > >
    > > Your use of Yahoo! Groups is subject to
    > > http://docs.yahoo.com/info/terms/
    > >
    > >
    >
    >
    > =====
    > Regards,
    >
    > Bob Pence
    >
    > NOTE: This mail is sent using my wireless phone. Calling me at 1 (610)
    563-6198 is preferred to a reply. If replying to this email address, please
    do not quote the original message.
    >
    > __________________________________________________
    > Do You Yahoo!?
    > Yahoo! - Official partner of 2002 FIFA World Cup
    > http://fifaworldcup.yahoo.com
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >
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