Re: A collection of monographs on high accuracy electronics

On 12/06/2024 12:11 pm, john larkin wrote:

On Wed, 12 Jun 2024 02:50:19 +0100, JM <sunaecoNoSpam@gmail.com>
wrote:
 

On Mon, 10 Jun 2024 15:14:40 -0400, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
>

On 2024-06-09 21:43, Phil Hobbs wrote:

On 2024-06-09 20:55, JM wrote:

On Mon, 10 Jun 2024 00:29:17 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
>

JM <sunaecoNoSpam@gmail.com> wrote:

On Sun, 9 Jun 2024 18:09:24 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
>

Jeroen Belleman <jeroen@nospam.please> wrote:

On 6/9/24 19:02, ehsjr wrote:

On 6/7/2024 9:14 PM, JM wrote:

A collection of monographs on high accuracy electronics written
by Mr.
Chris Daykin, following his career predominantly in metrology.
>
Unfortunately Chris will be unable to complete the unfinished
monographs (having started end of life care) but there is plenty of
interest to any analogue engineer.
>
https://1drv.ms/b/c/1af24d72a509cd48/EZhO_rP5-glDmxtc4ZHycvYBhrsqmyC5tuZjt2NFFsS0gQ?e=Wq2Yj0
>

>
>
Thanks!
Ed

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I have an issue with his definition of resistor noise power
as the product of open-circuit noise voltage and short-circuit
current. That makes no sense.
>
There's more than that, probably, but that just jumped out at
me.
>
Jeroen Belleman
>

>
It?s four times too high, for a start.
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Cheers
>
Phil Hobbs

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"It is shown elsewhere [1] that the noise power is four times the heat
energy which would flow down the conductors
from a warm source resistor to a matching cold resistor."
>

>
Which, if true, would solve all our energy problems, except that
thermodynamic systems would all be unstable.
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The thermal noise power produced by a resistor into a matched load is kT
per hertz.

>

>
Sure, which is what he states.  By mentioning a hot and cold resistor
he makes it clear that net energy flow is from hot to cold, and that
the T refers to the hot source.
>

But apparently he says that it's four times larger than that.
>
I'm not making a microsoft account just to download the PDF, so if you
want to discuss it further, you could email it to me.
>
Cheers
>
Phil Hobbs
>
>
>

Bill was kind enough to send me a copy (thanks again, Bill), and right
there on P. 374, the author says,
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Pn = 4kTB
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which is a factor of four too high.
>

>
No it isn't. He is calculating the thermal noise power dissipated in an unloaded resistor - something (or at least the related noise voltage) which is actually required in the design process of a transducer/amplifier low S/N system.

 What does that mean? Do unconnected resistors get hot?

No. They certainly don't get warmer than their enviroment, though they do interact with it.

A box of resistors could start a fire!

Obviously not. John Larkin's sense of humour is depressingly pathetic.
--
Bill Sloman, Sydney
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