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Groups > sci.electronics.design > #725716
| From | Bill Sloman <bill.sloman@ieee.org> |
|---|---|
| Newsgroups | sci.electronics.design |
| Subject | Re: Instead scopes |
| Date | 2024-09-03 15:30 +1000 |
| Organization | A noiseless patient Spider |
| Message-ID | <vb66t7$37ppr$3@dont-email.me> (permalink) |
| References | (8 earlier) <bmn9djt23ns3akfnfjaltiehr3ccuotkcs@4ax.com> <6p8adjh4ief0cfk1ohc1i54t6tob41q6o6@4ax.com> <nbgbdjtdf30hje01rqq5v0tptvpkknikbn@4ax.com> <vb4le6$2t5h0$1@dont-email.me> <pjccdjlu3d9glr745kpbsq9u6a6dqa28r0@4ax.com> |
On 3/09/2024 7:57 am, john larkin wrote: > On Mon, 2 Sep 2024 15:25:59 -0000 (UTC), Phil Hobbs > <pcdhSpamMeSenseless@electrooptical.net> wrote: > >> Joe Gwinn <joegwinn@comcast.net> wrote: >>> On Sun, 01 Sep 2024 19:49:39 -0700, john larkin >>> <jlarkin_highland_tech> wrote: >>> >>>> On Sun, 01 Sep 2024 17:43:32 -0400, Joe Gwinn <joegwinn@comcast.net> >>>> wrote: >>>> >>>>> On Sun, 01 Sep 2024 13:17:03 -0700, john larkin >>>>> <jlarkin_highland_tech> wrote: >>>>> >>>>>> On Sun, 01 Sep 2024 15:53:46 -0400, Joe Gwinn <joegwinn@comcast.net> >>>>>> wrote: >>>>>> >>>>>>> On Sun, 1 Sep 2024 17:55:58 -0000 (UTC), Phil Hobbs >>>>>>> <pcdhSpamMeSenseless@electrooptical.net> wrote: >>>>>>> >>>>>>>> john larkin <jlarkin_highland_tech> wrote: >>>>>>>>> On Sun, 1 Sep 2024 17:45:46 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> On 30/08/2024 2:21 am, Jan Panteltje wrote: >>>>>>>>>>> On a sunny day (Fri, 30 Aug 2024 00:43:39 +1000) it happened Bill Sloman >>>>>>>>>>> <bill.sloman@ieee.org> wrote in <vaq1f2$jdj$1@dont-email.me>: >>>>>>>>>>> >>>>>>>>>>>> It's lot easier and quicker to bread-board a circuit in LTSpice than it >>>>>>>>>>>> is to wire up a test circuit, but what that means is that you need to >>>>>>>>>>>> make fewer real circuits and they are a lot more likely to work when tested. >>>>>>>>>>>> >>>>>>>>>>>> That, on it's own, is enough to explain why labs look different today >>>>>>>>>>>> than they did in the dark ages. >>>>>>>>>>> >>>>>>>>>>> All it explains is boeings falling apart and astronuts ending up stuck at the ISS >>>>>>>>>>> and no moonlanding from the US, not even a probe. >>>>>>>>>>> Slimulations are _not_ realty and never will be. >>>>>>>>>> >>>>>>>>>> But they can capture useful parts of reality, if you know what you are >>>>>>>>>> doing. >>>>>>>>>> >>>>>>>>>> John Larkin's simulated inductors tend not to have any parallel capacitance. >>>>>>>>> >>>>>>>>> The trick is to know when it matters. ESR and core loss are usually >>>>>>>>> more important. >>>>>>>>> >>>>>>>>> I designed this surface-mount inductor for my Pockels Cell driver, >>>>>>>>> after several tries using commercial parts. They all smoked. >>>>>>>>> >>>>>>>>> It's wound on a specially marked Sharpie pen that we have carefully >>>>>>>>> reserved. >>>>>>>> >>>>>>>> It better have a regular calibration schedule, or your semiconductor >>>>>>>> customers may give you the raised eyebrow. >>>>>>> >>>>>>> Hmm. To be overly serious: With traceability to NIST (US) or NPL >>>>>>> (UK) or the like. >>>>>>> >>>>>>> The trend in standards is to eliminate standards tied to a physical >>>>>>> object. >>>>>>> >>>>>>> I have a Sharpie in hand. The barrel that is not covered by the cap >>>>>>> is a truncated cone, being 11.0 mm at the blunt end and 12.32 mm near >>>>>>> the cap, 73 mm away. >>>>>> >>>>>> Mine is pretty cylindrical for the length of the coil. I expect that >>>>>> the operator's (ie, my) applied tension affects the radius too. >>>>> >>>>> Most likely. >>>>> >>>>> >>>>>> That inductor sees 25 amps p-p, roughly a sawtooth, at 4 MHz. The >>>>>> Coilcraft parts that I tried all smoked, I guess from skin effect and >>>>>> proximity effect. >>>>>> >>>>>>> >>>>>>> Actually, all that's needed is to specify an ideal geometric shape, >>>>>>> with tolerances, in the formal documentation. >>>>>>> >>>>>>> Joe Gwinn >>>>>> >>>>>> I'll have someone start on a SolidWorks model. >>>>> >>>>> I bet you need the standoff, so the lossy FR4 material isn't too >>>>> close. That should be in the requirements as well. >>>> >>>> The turns squish down into the gap-pad gunk, which is an OK heat >>>> conductor. The PCB under the pad is a big copper pour, top and bottom, >>>> with a zillion thermal vias. There's more gap-pad on the underside of >>>> the board to dump heat into the baseplate. >>>> >>>> At 4 MHz, skin depth is 32 microns, so most of the copper is wasted. >>>> That's why it gets so hot. >>>> >>>> I tried three of the Coilcraft 1010VS parts in series, but they >>>> smoked, probably skin+proximity effect. Maybe parallel would have >>>> been better. >>>> >>>>> >>>>> I'd specify the coil dimensions, not the mandrel dimensions, which may >>>>> be provided as a helpful suggestion only. >>>>> >>>>> Joe Gwinn >>>> >>>> I could have a mandrel machined or 3D printed, to more accurately wind >>>> the inductor. The improvement would be mostly cosmetic. >>> >>> Or choose a 12mm OD mandrel, and adjust elsewhere. The advantage of >>> 12mm is that it's a common size. so just buy the rod and use it. >>> >>> .<https://www.mcmaster.com/products/shafts/shafts-2~/rotary-shafts-5/diameter~12-mm/> >>> >>> Actually, the requirement is a certain inductance while handling a >>> 4-MHz sawtooth at 25 Amps (p-p), so the frequency band is roughly 4 to >>> 20 MHz, to cover the first five harmonics Which harmonic causes the >>> most heating? >>> >>> The dimensions et al are the construction details needed for Highland >>> to be able to replicate the part without your help. >>> >> Lo these forty year gone, I had this RF gig that involved making a lot of >> VHF LC oscillatior and filter protos. > > I still design LC oscillators! You may put them together, but it sounds as if you evolve them rather than design them. And you'd have your own coil-winding gear if you did much of it. As Phil did. >> We had a hand-cranked coil winder that had a good selection of cylindrical >> steel mandrels with helical grooves to guide the wire, plus three or four >> sheets with tables of measured values for single-layer coils of various >> lengths. With a couple of training runs, one learned how hard to pull on >> the wire so that it would just spring free from the mandrel. >> >> That made it easy to make nice looking, high-Q coils for the inductance >> range of interest. Good Medicine. At George Kent in Luton (1973-76) I got to wind my own small-signal transformers. At Cambridge Instruments (1982-1991) I had to ask the coil-winders on the shop floor to do it for me. -- Bill Sloman, Sydney
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Instead scopes Martin Rid <martin_riddle@verison.net> - 2024-08-27 10:40 -0400
Re:Instead scopes Martin Rid <martin_riddle@verison.net> - 2024-08-27 10:48 -0400
Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-08-27 15:07 +0000
Re: Instead scopes wmartin <wwm@wwmartin.net> - 2024-08-29 12:24 -0700
Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-08-29 19:42 +0000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-27 09:30 -0700
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-27 09:04 -0700
Re: Instead scopes Martin Rid <martin_riddle@verison.net> - 2024-08-27 14:55 -0400
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-27 19:23 -0700
Re: Instead scopes Sergey Kubushyn <ksi@koi8.net> - 2024-08-28 04:28 +0000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-28 08:08 -0700
Re: Instead scopes Sergey Kubushyn <ksi@koi8.net> - 2024-08-28 15:21 +0000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-28 09:32 -0700
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-29 05:46 +0000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-29 06:55 -0700
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-29 07:16 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-30 00:43 +1000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-29 08:49 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-30 14:10 +1000
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-29 16:21 +0000
Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-29 11:47 -0700
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-30 06:47 +0000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-30 07:13 -0700
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-30 08:29 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-31 16:08 +1000
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-31 01:39 +1000
Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-30 10:18 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-31 15:40 +1000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-31 06:53 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-01 02:11 +1000
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-30 18:22 +0000
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-31 07:38 +0000
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-01 17:45 +1000
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-01 11:06 +0000
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-01 21:38 +1000
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-01 12:41 +0000
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-02 01:56 +1000
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-02 02:34 +0000
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-02 16:54 +1000
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-02 10:37 +0000
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-02 23:28 +1000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-01 07:09 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-02 02:20 +1000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-01 13:32 -0700
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-02 02:48 +0000
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-02 02:53 +0000
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-02 17:13 +1000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-02 08:31 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-03 15:11 +1000
Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-09-01 17:55 +0000
Re: Instead scopes Joe Gwinn <joegwinn@comcast.net> - 2024-09-01 15:53 -0400
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-01 13:17 -0700
Re: Instead scopes Joe Gwinn <joegwinn@comcast.net> - 2024-09-01 17:43 -0400
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-01 19:49 -0700
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-02 02:56 +0000
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-02 17:52 +1000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-02 08:45 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-03 15:20 +1000
Re: Instead scopes Joe Gwinn <joegwinn@comcast.net> - 2024-09-02 10:02 -0400
Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-09-02 15:25 +0000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-02 14:57 -0700
Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-09-02 22:32 +0000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-04 07:41 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-03 15:30 +1000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-04 07:50 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-05 16:54 +1000
Re: Instead scopes john larkin <jl@650pot.com> - 2024-09-03 11:39 -0700
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-02 08:51 -0700
Re: Instead scopes Joe Gwinn <joegwinn@comcast.net> - 2024-09-02 12:47 -0400
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-09-02 08:36 -0700
Re: Instead scopes Joe Gwinn <joegwinn@comcast.net> - 2024-09-02 12:39 -0400
Re: Instead scopes piglet <erichpwagner@hotmail.com> - 2024-09-09 19:51 +0100
Re: Instead scopes Jeroen Belleman <jeroen@nospam.please> - 2024-09-09 22:24 +0200
Re: Instead scopes liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2024-09-09 22:15 +0100
Re: Instead scopes john larkin <jl@650pot.com> - 2024-09-09 14:40 -0700
Re: Instead scopes john larkin <jl@650pot.com> - 2024-09-09 14:27 -0700
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-29 16:15 +0000
Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-29 11:50 -0700
Re: Instead scopes liz@poppyrecords.invalid.invalid (Liz Tuddenham) - 2024-08-29 21:50 +0100
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-31 07:24 -0700
Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-08-31 17:59 +0000
Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-31 11:44 -0700
Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-08-31 20:14 +0000
Re: Instead scopes ehsjr <ehsjr@verizon.net> - 2024-08-31 17:43 -0400
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-31 16:40 -0700
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-08-29 16:06 +0000
Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-29 11:52 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-29 20:23 +1000
Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-29 11:59 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-30 14:17 +1000
Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-30 10:14 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-08-31 16:03 +1000
Re: Instead scopes john larkin <jlarkin_highland_tech> - 2024-08-31 07:03 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-01 01:43 +1000
Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-31 11:57 -0700
Re: Instead scopes Bill Sloman <bill.sloman@ieee.org> - 2024-09-01 15:15 +1000
Re: Instead scopes Jan Panteltje <alien@comet.invalid> - 2024-09-01 07:36 +0000
Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-08-28 17:41 +0000
Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-28 13:05 -0700
Re: Instead scopes Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2024-08-29 19:15 -0400
Re: Instead scopes john larkin <jl@650pot.com> - 2024-08-29 16:44 -0700
Re: Instead scopes Joerg <news@analogconsultants.com> - 2024-09-09 14:57 -0700
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