Path: ...!Xl.tags.giganews.com!local-2.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Wed, 12 Jun 2024 02:11:51 +0000 From: john larkin Newsgroups: sci.electronics.design Subject: Re: A collection of monographs on high accuracy electronics Date: Tue, 11 Jun 2024 19:11:51 -0700 Message-ID: <1j0i6j9uoo7c0b59btpopsapf1q29t61q5@4ax.com> References: <33c76j1cr78uhuk3djabivck4gbpe4dq9i@4ax.com> <6djc6jhurdaoqkvgnp0rcb1f4tci4da5pm@4ax.com> <5a46f302-382b-12de-f41d-61335179fe63@electrooptical.net> User-Agent: ForteAgent/8.00.32.1272 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Lines: 89 X-Trace: sv3-8lFeI/hni/seQqTs2+VKhdQ4IjWnPFvnRUeWxGtf+73m5Wy4xcVPDuzrhUOQFktrGXfuONfU3mOMgl5!eE/5gD9KkP+77cGxJR9TUONscKDBkCLeupYC00LUTJK4OOvF6nZcFCH1/XNjuqJ54quf2cyleKT4!MQpAjg== X-Complaints-To: www.supernews.com/docs/abuse.html X-DMCA-Complaints-To: www.supernews.com/docs/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Bytes: 4581 On Wed, 12 Jun 2024 02:50:19 +0100, JM wrote: >On Mon, 10 Jun 2024 15:14:40 -0400, Phil Hobbs 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 >>>> wrote: >>>> >>>>> JM wrote: >>>>>> On Sun, 9 Jun 2024 18:09:24 -0000 (UTC), Phil Hobbs >>>>>> wrote: >>>>>> >>>>>>> Jeroen Belleman 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 >>>>>>>> >>>>>>>> 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. >>>>>>> >>>>>>> Cheers >>>>>>> >>>>>>> Phil Hobbs >>>>>> >>>>>> "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. >>>>> >>>>> 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, >> >>Pn = 4kTB >> >>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? A box of resistors could start a fire!