Path: ...!Xl.tags.giganews.com!local-1.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail
NNTP-Posting-Date: Mon, 02 Sep 2024 15:36:54 +0000
From: john larkin <jlarkin_highland_tech>
Newsgroups: sci.electronics.design
Subject: Re: Instead scopes
Date: Mon, 02 Sep 2024 08:36:53 -0700
Message-ID: <cmmbdjp4p75m5ub1oijsat42g8s2lcfhi8@4ax.com>
References: <mtjucjdqe2f91c2jsjp6011k0uvakuimog@4ax.com> <vap20i$1s5cl$1@solani.org> <8dv0djhj73b0ejudpkahnojgjk30i9rrbv@4ax.com> <je01dj177m9p0q25en4k2jm8u0bsj07t2j@4ax.com> <vaq1f2$jdj$1@dont-email.me> <vaq762$1ssg1$1@solani.org> <vb163a$1dt9b$1@dont-email.me> <0ns8djtqe7ct4k21h8ubnj944fonq9i0u0@4ax.com> <vb29rd$1isoo$1@dont-email.me> <l4h9djl9rg8qip36cq0luehvf8cqprklbt@4ax.com> <orh9dj1svvp2i1rnhbkt3266uovqotofi4@4ax.com> <bmn9djt23ns3akfnfjaltiehr3ccuotkcs@4ax.com>
User-Agent: ForteAgent/8.00.32.1272
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Lines: 93
X-Trace: sv3-L9mCEp/QDw8zaPl37SCcZCEjnzsMiHs1ksf7mIX1bngnZP6OaQCcoXCv5NDKsQKMdMCeSFlFFWMz6ce!7AA4nhBoPSCvyxuO7L+t9ikoOy/2iIJCPxScDUAPw64RQdqwCUIgihrgBt9EK946KWJx17+wNK03!QFpejw==
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: 4922

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.

That's another function of the gap-pad material. And the flattish part
of the circular solenoid windings make a big contact area into the
pads, for more heat transfer.

>
>I'd specify the coil dimensions, not the mandrel dimensions, which may
>be provided as a helpful suggestion only.

It would be cool is the bottom of the windings were actually flat, a
square or elliptical winding, for more heat transfer area. 


>
>Joe Gwinn