So anyhow issue is when series connected pot-core inductors are stacked in end-to-end contact they saturate way below calculated current corresponding to saturation flux density! But if they're separated even just a few mm current for Bsat is exactly what's expected!

Fancy that!

So I totally get it's cuz of _static_ field around cores (from DC component of current through inductors) somehow biasing neighboring inductor's core material towards saturation but I say that's weird cuz upper limit of flux density in any single inductor in chain of series connected identical inductors is asymptotic to flux density in single inductor's (full) crossection! So that means field from other inductors in setup can't have that effect even if perfectly coupled (cuz they all have same B and o/c B doesn't add, just superimposes maximum) and ayhow they're hardly coupled at all cuz of cancelling (so shielding) effect of pot-core geometry!

--Emphasis Added--
The statement (highlighted above) applies only where μe = μr... (i.e. where the effective permeability of the core equals [or, as a practical matter, closely approaches] the relative permeability of the core material)...

Please consider the following (Re: PC-3019 pot cores fashioned of #77 ferrite):

Ideal ungapped (single piece core [g=0]) μe=μr = 2000 (note that for these purposes conflation of μi (material initial permeability) and μr is appropriate even if a 'tad' expedient)

Practical 'ungapped' (tightly clamped two-piece core ['inherent' g ≈ 6um]) μe ≈ 1600

Gapped inductors under discussion g=500um μe≈86 --- Dig it?

Granted! By virtue of the rather scant core-to-core coupling apparent in the described arrangement - the implied four-fold reduction in I(Bsat ) is not practically realizable! -- That said, owing the 'second degree relationship' of μe to Al (and, hence, I[Bsat]) taken with the fact that the described 'shielding' is notably less effective than mere 'ISL effects' as regards attenuation of static fields -- a 40%-50% I(Bsat) reduction is quite anticipatable!

FWIW a (likely inconsequential) 'aside'/point of interest is to be noted in said material's rather low volume resistivity (Spec: 100Ω/cm) while I've afforded little thought to the implications of inter-inductor electrical contact, such would seem worthy of consideration?...

Well hey! @Aleph(0) I apologize that the foregoing is about all time permits for the nonce (busy, busy, busy -- and FF is as ratty as ever) -- Please rest assured I will get to the remainder of your recent questions/comments ASAP!

Very best regards
HP

PS

OMG! He is JC's ringer! Check this out:

Indeed! The veritable 'spit and image' of JC! -- But sans his bike! 'Tis as regarding a hermit crab bereft of a shell!

 

@Aleph(0)?

Should you have any additional questions/comments please post them here ASAP such that I may address your recent content via a single post...

Many thanks!
HP

 

@Aleph(0) --- No problems here Please keep trying - should you continue to experience difficulty I'll post a message on your behalf in 'feedback'...

 

@Aleph(0) --- No problems here Please keep trying - should you continue to experience difficulty I'll post a message on your behalf in 'feedback'...

HP tnx! It's working now so I say it was just my lame VPN or FF striking again

Anyhow error was just message saying _Page has expired plz try again_ no matter what when I tried to login But sndex monitor showed vpn effed time zone up by +12hrs (so 12:nn pm instead of 12:nn am) so maybe that had to do with it! Anyhow important thing is it was definitely NOT AAC bug so no need for post on feedback fourm

@Aleph(0)?

Should you have any additional questions/comments please post them here ASAP such that I may address your recent content via a single post...

Many thanks!
HP

HP Only to ask what YOU want to do abt winding/gapping formulae? So I say just show them how you picked acceptable Bmax and realistic gap and took it from there! Cuz after all it's just for decoupling choke in test circuit! So comprehensive lesson can wait for when we're into theory and design. So anyhow it's totally your call but if Alpha team is representative of target readership I can tell you right now that _a dose of magnetics_ at this stage is like _too boring too early_

 

HP Only to ask what YOU want to do abt winding/gapping formulae?

Might I inquire as to what part of:

Aleph? What's the problem? You're welcome to post the formulas you've been 'handing out'.

you find incomprehensible? Was my improper declension that confusing?

Further to this topic, I'm bound register my strong distaste for 'AL' (a..k.a. 'inductance factor', etc...)! -- Although, as a concession to 'convention', I have heretofore entertained said utilitarian vulgarism -- I assert that the concept of permeance (not to be confused with 'permeability') is neither particularly abstruse nor otherwise 'challenging'!

To all readers: While all interested parties are genuinely welcome and encouraged to participate - please be advised that these tutorials are neither offered nor intended as exercises in 'Tech-Ed'! --- To those seeking such 'instruction' (such that it is) I suggest that Youtube or, indeed, your local 'bricks and mortar' 'Votech' will likely be your best contact...

Attention alpha team and everyone reading thread! Links 2 other posts on this thread are totally effed up right now but we're working on it so plz just bear with us!

--Emphasis Added--

@Aleph(0) - I must say that your native social grace and instinctive sense of professionalism are as charming as ever!


Jadedly
HP

 

@Aleph(0) - I must say that your native social grace and instinctive sense of professionalism are as charming as ever!

HP OK already! So how's this?

To all concerned: As a result of _content management_ most internal and external links to posts on this thread are currently misaddressed. Your patience is greatly appreciated pending our resolution of this issue.

The current version of tutorial starts HERE! Tnx!

Edited for formality by Aleph(0) 2/20/18

HP remember how you said abt picturing JC w/o his bike?

'Tis as regarding a hermit crab bereft of a shell

So I say that's exactly how you're making me feel forcing me out of numpty persona!

 

HP OK already! So how's this?

Edit Feb 20 2018

To all concerned: As a result of _content management_ most internal and external links to posts on this thread are currently misaddressed. Your patience is greatly appreciated pending our resolution of this issue.

Much improved! -- Thank you!

HP remember how you said abt picturing JC w/o his bike?
So I say that's exactly how you're making me feel forcing me out of numpty persona!

Indeed...? Am I to understand that said 'strain' is responsible for your neglect of the central focus of my post?

Please be advised that I'm growing rather weary of this protracted, sniveling affair of the decoupling choke! You are free to offer the winding/gapping advice with or without attendant formulae as you choose! -- In any event 'magnetics' will indeed receive comprehensive treatment in 'Driver Design'...

Best regards
HP

 

Please be advised that I'm growing rather weary of this protracted, sniveling affair of the decoupling choke!

HP if you think ur getting tired of it how do you think I feel trying to explain basic concepts like distinction of magnetic field strength vs flux density (so H vs B) to ppl totally poisoned by MORONIC EDUCATION SYSTEM that isn't even consistent with terminology! HP being totally serious I thought Babs B. was exaggerating until I looked on postgrad textbooks she cited where they conflate and alternate terms even sometimes in same paragraph! (BTW I fwded email to ur home addy so you could see lame rationalizations and excuses from one publisher). HP I say is ironic cuz remember we had criticism that tutorial is more formal than textbook? So now I'm saying I HOPE SO!

HP Being 100% serious it's totally frighting how much shameless _professional ignorance_ is out there among so called professionals including credentialed scientists and educators!

So Alpha team this ISN'T rant abt you! Cuz I say ur way above average for ppl starting out to even ask questions and challenge contradictions instead of just going through motions like your (which includes my) generation was PROGRAMED to do! So tnx for thinking! And tnx for putting my mind at ease! Cuz since ur basically random sample of ppl interested in topic, you proved that we're not wasting our time expecting target readership to critically think for themselves!

sniveling affair of the decoupling choke!

HP even though just decoupling inductor can definitely seem that way, I say if we introduce magnetics at all we need to do it unambiguously! Cuz otherwise we risk leaving them with misconceptions and bad habits 2b overcome later when we get onto more advanced magnetic topics like mutual inductor design! So I say acceptable options can be either <1> give them quantitative context for choke design or <2> just instructions on how to construct it! Cuz with option <1> they have like 'primer' on magnetics and with option <2> there's no harm done and it lets us wrap up _mechanical_ phase more quickly and so move on to engineering/science topics! So HP it's totally your call but as far as I can think those are only viable options?

You are free to offer the winding/gapping advice with or without attendant formulae as you choose!

Sry HP it's as YOU choose! Cuz I'm not taking blame if it puts them to sleep or scares them away! So on other side of argument a lot of ppl on team are vry interested in topic of magnetics so it could pay to like _strike while iron is hot_ cuz if they can't satisfy their curiosity here they'll turn to crowd-sourced online references which have seriously messed a few of them up already! So I say it totally sux that now being an instructor basically requires being like a _deprogrammer_ too!

 

HP if you think ur getting tired of it how do you think I feel trying to explain basic concepts like distinction of magnetic field strength vs flux density (so H vs B) to ppl totally poisoned by MORONIC EDUCATION SYSTEM that isn't even consistent with terminology!

But then it is my painful awareness of said fact that 'drives' my circumspection in this matter...

HP Being 100% serious it's totally frighting how much shameless _professional ignorance_ is out there among so called professionals including credentialed scientists and educators!

Well indeed it is! -- Though I daresay said observation is hardly 'novel' - our contribution to the remediation of which (I hasten to remind you) being, in no small part, the 'mission' of our series...

HP being totally serious I thought Babs B. was exaggerating until I looked on postgrad textbooks she cited where they conflate and alternate terms even sometimes in same paragraph!

crowd-sourced online references which have seriously messed a few of them up already!

And for said references' not inconsiderable limitations, one of them (at least) appears to share your observation:

The term "magnetic field" is historically reserved for H while using other terms for B. Informally, though, and formally for some recent textbooks mostly in physics, the term 'magnetic field' is used to describe B as well as or in place of H. There are many alternative names for both...

--Emphasis added--

So Alpha team this ISN'T rant abt you! Cuz I say ur way above average for ppl starting out to even ask questions and challenge contradictions instead of just going through motions like your (which includes my) generation was PROGRAMED to do! So tnx for thinking! And tnx for putting my mind at ease! Cuz since ur basically random sample of ppl interested in topic, you proved that we're not wasting our time expecting target readership to critically think for themselves!

Double ditto! - - 'Tis as a new (and most welcome) 'slant' on the well-neigh 'venerable' expression - to wit: 'thanks for thoughts'

I say if we introduce magnetics at all we need to do it unambiguously! Cuz otherwise we risk leaving them with misconceptions and bad habits 2b overcome later when we get onto more advanced magnetic topics like mutual inductor design!

And I suggest that a succinct --indeed, even cursory-- treatment needn't be with the penalty of ambiguity -- Of course comprehensive treatment at the appropriate juncture goes without saying...

So I say it totally sux that now being an instructor basically requires being like a _deprogrammer_ too!

For all that I expect 'un-learning' misconceptions and 'breaking' bad habits are --and always have been-- the principle obstacles to all manner of self improvement...

Sry HP it's as YOU choose!

As we've known since last autumn, 'outside' demands upon my time will likely remain significant prior to late July/ early August -- That said, I am presently 'handling' the matter under discussion as well as composition of the EHT indicator construction tutorial (mercifully the imaging is complete and resident on my AAC blog)...

Very best regards
HP

PS

HP I say is ironic cuz remember we had criticism that tutorial is more formal than textbook? So now I'm saying I HOPE SO!

Indeed! -- For the benefit of interested/concerned parties: Please be advised that the intended tone of our tutorial series is that of the 'descriptive text' - which being (as regards educational material) rather more formal than a typical 'curricular' 'text book' all the while very much more 'concept oriented' than a 'technical paper'...

 

And for said references' not inconsiderable limitations, one of them (at least) appears to share your observation:

HP that's vry nice cuz I swear I didn't edit that article or even see it! So I say score one for Wikipedia!

As we've known since last autumn, 'outside' demands upon my time will likely remain significant prior to late July/ early August

HP just chill cuz I'm not saying ur shirking! Just that matters of presentation are totally up to you cuz there's no pleasing everyone and if it's my work I know from experience that all I'll hear abt are the _negatives_ even if they're <1%

That said, I am presently 'handling' the matter under discussion

HP sry but that's ambiguous? Do you mean you plan to do something abt it or just that ur _bearing up_ under the strain?

as well as composition of the EHT indicator construction tutorial

HP Tnx! That's totally important cuz most ppl need meter to test rebuilt FB before moving on to driver design! Now o/c I know they could just look on arc for test purpose but I say basically telling them to _play with electricity_ is asking for trouble at this stage!

For the benefit of interested/concerned parties: Please be advised that the intended tone of our tutorial series is that of the 'descriptive text' - which being (as regards educational material) rather more formal than a typical 'curricular' 'text book' all the while very much more 'concept oriented' than a 'technical paper'...

HP Since we've been explaining that for like three years I say anybody who doesn't get it by now prolly never will!

 

So I say score one for Wikipedia!

One doesen't often hear that?!

I know from experience that all I'll hear abt are the _negatives_ even if they're <1%

But then --as per your 'refrain'-- Positive feedback is nice but it's negative feedback that 'catches' the problems

HP sry but that's ambiguous? Do you mean you plan to do something abt it or just that ur _bearing up_ under the strain?

Both!

o/c I know they could just look on arc for test purpose but I say basically telling them to _play with electricity_ is asking for trouble at this stage!

Agreed!

HP Since we've been explaining that for like three years I say anybody who doesn't get it by now prolly never will!

Yebut... We can hardly expect new readers to 'sift through' ca three years of idle musings - 'gem salted' though said 'trail' may be

Very best regards
HP

 

HP sry but that's ambiguous? Do you mean you plan to do something abt it or just that ur _bearing up_ under the strain?

emphasis mine

Both!

Well?

 

Well?

Well what? I shouldn't have thought I'd need remind you I'm yet awaiting your report?

Tolerantly
HP

 

Well what? I shouldn't have thought I'd need remind you I'm yet awaiting your report?

Tolerantly
HP

I just love how you tolerate each other. I think we can make a soap opera from you two. )

 

I just love how you tolerate each other. I think we can make a soap opera from you two. )

Indeed! Such has been 'explored' previously

@OBW0549 (I believe it was?) suggested a title of: 'As The Anode Turns'




And...Oh my! A fractured anode at that! - Golly!

TTFN
HP

 

--Index test--
https://forum.allaboutcircuits.com/blog/lopt-tutorial-in-progress-volume-a.1117/

 

ATTN: @Aleph(0) / Alpha team

Re: Blog access via 'Orange Style':

While indeed the 'Blog Entries' link in 'member profile' is dysfunctional (i.e. links to a single page of truncated/scrambled HTML code) my blog may, nonetheless, be accessed via the "Hypatia's Protege's Blog" link in my member popup

Note that the above described difficulty and 'workaround' are manifest without regard to session status (i.e. 'logged-in' vs 'guest') -- Please pass it along!

Best regards
HP

 

ATTN: @Aleph(0) / Alpha team

Re: Blog access via 'Orange Style':

While indeed the 'Blog Entries' link in 'member profile' is dysfunctional (i.e. links to a single page of truncated/scrambled HTML code) my blog may, nonetheless, be accessed via the "Hypatia's Protege's Blog" link in my member popup

Note that the above described difficulty and 'workaround' are manifest without regard to session status (i.e. 'logged-in' vs 'guest') -- Please pass it along!

Best regards
HP

HP MAJOR Tnx!

Indeed! Such has been 'explored' previously

@OBW0549 (I believe it was?) suggested a title of: 'As The Anode Turns'

View attachment 147757


And...Oh my! A fractured anode at that! - Golly!

TTFN
HP

HP Just cuz of curiosity, is that the bad insert u depoted from Dunlee head or just pic from web?

 

@Hypatia's Protege (Alpha testers this is FYI too!)

HP I know you haven't added text for HV winding test procedure yet but plz put warning about LV psu at end of tutorial right away! Cuz some Alpha testers who are _working ahead_ have basically nuked their SMPSs using them 2 power FB test driver! So I totally let them know that when we get to proper drivers they'll be designed _PSU friendly_ but for now LV PSU for just test circuit needs 2b super simple unregulated linear! So line filter, variac, isolating SD xfmr, bridge and filter caps with MOV to protect rectifiers! So I'm telling them max output of 60V at 25A is fine!

So HP I say this is latest in litany of problems caused by fact that I can't access ur blog to make edits and additions which totally limits my helpfulness! So I say there are just two solutions!

◊You could tell me your PW so I can login to your acct and edit your blog directly (so if you want to do that I totally promise to identify every post as myself in bold text and always keep it to just editing/composing in ur blog and also I promise NO stoned posting!)

OR

◊You need to find MAKE time to respond to problems in timely fashion cuz as it stands it's just not working out!

 

HP I know you haven't added text for HV winding test procedure yet but plz put warning about LV psu at end of tutorial right away!

Excellent idea! -- Inasmuch as said monition will, IMO, be significantly 'enhanced' via images of typical components and a rough schematic of the suggested device, said amendment must needs await my return to my 'field' lab (Aprox 10 to 14 hours from the time of this writing)...

but for now LV PSU for just test circuit needs 2b super simple unregulated linear! So line filter, variac, isolating SD xfmr, bridge and filter caps with MOV to protect rectifiers! So I'm telling them max output of 60V at 25A is fine!

Agreed! -- Said 'amendment' will include images of (representative) components and a general schematic indicative of suggested component values - That said --barring significant call for same-- I am with neither intent nor desire to 'walk them through' so basic a task as assembly of an unregulated linear low 'voltage' PSU! -- Interpretation of schematic diagrams, conversance with fundamental electrical principles/construction techniques must be deemed prerequisites is maintenance of scope to be achieved!

◊You could tell me your PW so I can login to your acct and edit your blog directly (so if you want to do that I totally promise to identify every post as myself in bold text and always keep it to just editing/composing in ur blog and also I promise NO stoned posting!)

As you are aware I would be most uncomfortable with any solution entailing sharing of our 'accounts'! -- As I see it, the demands of coherency, credibility and, indeed, extension of basal courtesy to the readers require maintenance a single, genuine voice per contributor!

◊You need to find MAKE time to respond to problems in timely fashion cuz as it stands it's just not working out!

Indeed!

Very best regards
HP

PS

HP Just cuz of curiosity, is that the bad insert u depoted from Dunlee head or just pic from web?

--Emphasis Added--
The latter -- As per AP's request, I've donated (ahem... 'unloaded') my holdings of 'fractured-anode' Coolidge tubes to his 'Tech College' (seems they're useful by way of demonstrating the result of failure to observe thermal duty cycle!) -- Yes! I know! Anode fractures more commonly owe to uneven heat distribution secondary to bearing failure -- Still... I'm certain I sleep better nights knowing I've done my part to combat cruel (even if all too usual) treatment of electron tubes!