Path: ...!weretis.net!feeder8.news.weretis.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: john larkin Newsgroups: sci.electronics.design Subject: Re: more X-rays Silvertel PoE Supply Date: Thu, 03 Oct 2024 09:04:55 -0700 Organization: A noiseless patient Spider Lines: 72 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Injection-Date: Thu, 03 Oct 2024 18:04:55 +0200 (CEST) Injection-Info: dont-email.me; posting-host="aa46a8725e0df1c31bac752603293f78"; logging-data="3990286"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/IGfUPbO2EabTuJJc3f+Ef" User-Agent: ForteAgent/8.00.32.1272 Cancel-Lock: sha1:qeAwJaLMIlsWq75jWvSMw66kzeQ= Bytes: 4299 On Thu, 03 Oct 2024 06:38:41 GMT, Jan Panteltje wrote: >On a sunny day (Wed, 02 Oct 2024 15:39:31 -0700) it happened john larkin > wrote in : > >>On Wed, 2 Oct 2024 17:00:52 -0400, "Edward Rawde" >> wrote: >> >>>"john larkin" wrote in message news:kqbrfjhrd5oto8ud8vm0395p6oo8eipige@4ax.com... >>>> On Wed, 2 Oct 2024 11:46:21 -0400, "Edward Rawde" >>>> wrote: >>>> >>>>>"john larkin" wrote in message news:v6mqfjd93ib6q8j7d7ontsaouidieh5b2u@4ax.com... >>>>>> On Wed, 02 Oct 2024 06:22:43 GMT, Jan Panteltje >>>>>> wrote: >>>>>> >>>>>>>On a sunny day (Tue, 01 Oct 2024 14:16:09 -0700) it happened john larkin >>>>>>> wrote in : >>>>>>> >>>>>>>> >>>>>>>>https://www.dropbox.com/scl/fo/s6wfz2xtdyd6tv32tq3fp/AET6J4oF84HG2hJMeST6F-E?rlkey=acyvuv4z0h2kg0x97azbed8uo&dl=0 >>>>>>> >>>>>>>Cannot make out much from those x-rays, pictures are better... >>>>>>>you can probably see the traces just like that? >>>>>> >>>>>> The x-rays are fun, but are admittedly more useful for an opaque >>>>>> potted module or an IC or discrete semi. I can prety well trace the >>>>>> Silvertel without them. >>>>>> >>>>>> I have a gigantic scary Carribean guy who does the xrays and I wanted >>>>>> an excuse for taking him to lunch, which turned into an interesting >>>>>> hike around The Bernal Cut. He trashed the xray system software, and >>>>>> had to rebuild it, and now it can do movies, which is great. >>>>>> >>>>>> I'd like to have some products that can be powered by PoE or a wart, >>>>>> and may want to put two 24-volt PoE supplies in series to get 48, so I >>>>>> need to understand how they work. The xrays just help a bit. >>>>> >>>>>If Ag9900 just works then why would you care how? >>>> >>>> Can I overpower it with a wart? Does that need another diode? >>> >>>Maybe. See other discussion in this thread. >>> >>>> >>>> Can I run two 24v Silvertels in series to get 48? >>> >>>I don't see why not since the data sheet says isolated. >>>It shouldn't be hard to verify that. >> >>Batteries are isolated, but a series string can destroy one cell by >>back-biasing it. >> >>Some power supplies will latch up, or not start up, in series with >>others. Lots of suplies won't start (and may fail) if their input is >>pulled negative. >> >>As the number of items in a design increases, the probability of some >>stupid error approaches unity. It's usually time efficient to be super >>careful, as opposed to spinning a few PCB revs. > >Why always some XXXchip? >What's wrong with designing with normal components and adding a known micro? That's exactly what I'm doing. Stock parts and an RP2040 CPU chip. There are *so many* Raspberry Pi kids out there! Now if I could build the hardware part of the product with Legos...