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)...

HP so now it's been abt 19 Hrs! SO WHERE IS IT?

As I see it, the demands of coherency, credibility and, indeed, extension of basal courtesy to the readers

HP I totally agree all that's vry important! But so is having content for readers to study!

The latter -- As per AP's request, I've donated (ahem... 'unloaded') my holdings of 'fractured-anode' Coolidge tubes to his 'Tech College'

HP since anodes contain like 140 Grams (so like $8500) worth of rhodium each, I say it's fair to say you donated them! Heh! At value of ≈ $1900 per Troy ounce I say Rh totally kicks stainless in its tail-section!

So now is my turn to say I expect to see some progress when I'm back young lady!

 

HP so now it's been abt 19 Hrs! SO WHERE IS IT?

I believe she was referring to Venusian sidereal time ... so cut her some slack ...

 

I believe she was referring to Venusian sidereal time ... so cut her some slack ...

Ha ha! I say HP totally lives on Venusian or more like Mercurian time!

 

Ha ha! I say HP totally lives on Venusian or more like Mercurian time!

... as long as she doesn't have a Mercurian personality! ...

 

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

HP so now it's been abt 19 Hrs! SO WHERE IS IT?

@Aleph(0) - How's about this?
/////////////////////////////////////////

Following is an 'off the cuff' example of an unregulated low 'voltage' power supply suitable for testing/prototyping certain circuits described in our 'EHT PSU' Tutorial series -- the circuit under discussion being, as it is, after the fashion of a 'battery eliminator' continuously adjustable from 0 Vdc-50 Vdc @30A).

Please note that this post is not a tutorial/construction project! But merely a 'bare-bones' example/outline of a 'workable expedient' -- Moreover, the following assumes operation from 120V/20A residential service - the reader is credited with sufficient savvy and initiative to effect necessary adjustments where other operating conditions prevail -- That said, we'll gladly assist anyone genuinely experiencing difficulty!

Generalized schematic (Note that load-generated noise mitigation has been left in abeyance)...

Major component descriptions:

Note: The US $20 banknote is included for perspective.

Potted line filter:
Function: Exclusion of line disturbances (e.g. noise/transients) from the PSU and vice-versa...

---Required Characteristics---
⇒Current handling rating (continuous) ≥ 15A
⇒Provision for both common and differential mode noise attenuation

Typical common/differential mode line filter

Variac (variable auto-transformer):
Function: to provide continuously adjustable sinusoidal drive to the step-down transformer

---Required Characteristics---
Current rating (continuous) ≥15A

Example of a 120V/15A variac

Step down isolation transformer:
Function: (In addition to impedance transformation) to provide (electrical) line isolation...

---Required Characteristics---
⇒2:1 Pri/Sec turns ratio
⇒Primary current rating (continuous) ≥ 15A
⇒Secondary current rating (continuous) ≥30A -- Without regard to primary requirements.
⇒Secondary EMF (fully loaded) ≥ 45V -- Without regard to primary requirements.
Note that such a device may be readily fashioned via modification of a 1:1 'line-conditioner' transformer...

Example of a 16A 1:1 isolation transformer -- Readily modifiable for 2:1 (TR) step-down (i.e. 120V@16A Pri/60V@32A Sec) operation.

Bridge Rectifier:
---Required Characteristics---
⇒Prv≥200V
⇒If(Continuous)≥30A
⇒If(surge)≥100A

Note that while an arrangement of four discrete industrial rectifiers is strongly recommended - A significantly less costly 'off the shelf' potted module exhibiting an I(fwd) Spec ≥ 30A (continuous) will suffice -- Be it known, however, that the recommended rectifiers or equivalents thereof (Ifwd=300A continuous/20kA surge) will easily survive protracted 'dead short' conditions whereas consumer-grade devices will undergo catastrophic failure prior to opening of even the fastest over current protection devices!

Typical industrial Si rectifier diodes (Ifwd[cont] = 300A, Ifwd[surge]=20KA, Prv = 1kv)

Filter Capacitor{S}:

---Required Characteristics---
⇒Capacitance ≥30 millifarads (total)
⇒Working EMF ≥ 50V
⇒Surge EMF ≥ 65V
⇒ESR≤15Ω

Note: Reliability and general applicability demand eschewal of 'super capacitors' and their ilk!

24mF electrolytic capacitors representative of the style suited to the proposed application

---Protection components---
Note: positional citations are with reference to the schematic (near the top of this post).

OVP(left) Zener transient suppressor:
Function: Preclusion of filter capacitor abuse corollary to EMF up-swings during near maximum output EMF operation.

---Required Characteristics---
V(br)≈53V
Ipp=150A

OVP(Right) MOV selected for 5ma leakage at 45V
Function: Exclusion of load-induced transients.

---Required Characteristics---
W(tm)≥5kJ
I(tm)≥60kA

Note: MOVs are preferred to GDTs in this application for the former's significant effective shunt capacitance.

OCP(left), OCP(mid), OCP(right) 'Semiconductor fuses'.
Function:
Left -- Disconnection of bridge in event of OVP(left) conduction.
Mid -- Disconnection of filter capacitors in event of OVP(left) conduction.
Right -- Disconnection of filter capacitors in event of OVP(right) conduction
Any/All -- Disconnection of PSU in event of overload/disconnection of components in event of failure.

---Required Characteristics---
Ic=35A
Ii≥50kA
TC(i)≤10ms

Best regards
HP

 

the reader is credited with sufficient savvy and initiative to effect necessary adjustments where other operating conditions prevail

HP I say even though circuit is basically like just a ballsy model railroad PSU you're being totally too optimistic abt newbies, as usual!

Variac (variable auto-transformer):
Function: to provide continuously adjustable sinusoidal drive to the step-down transformer

HP I say anybody who doesn't already know that is in totally the wrong place!

Step down isolation transformer:

Note that such a device may be readily fashioned via modification of a 1:1 'line-conditioner' transformer...

So for ppl who need more detail on that here's what you need to do:

◊Remove Xfmr bunting to expose top winding (which is original primary that will now be secondary).

◊Find electrical center of winding by noting null-point from ends while other winding is energized (by just a few volts for safety).

◊Cut winding exactly at null point and unwrap each new inside end one turn so now new secondary winding is two windings which I'll just call windings _A_ and _B_.

◊Connect new secondary windings in electrical parallel by connecting outside end of Wdg A to inside end of Wdg B and inside end of Wdg A to outside end of Wdg B.

◊So stepped down output is taken from across windings!

Note that while an arrangement of four discrete industrial rectifiers is strongly recommended - A significantly less costly 'off the shelf' potted module exhibiting an I(fwd) Spec ≥ 30A (continuous) will suffice

HP Sry but that's just lame! Cuz industrial rectifiers like those from Alegretti only cost like $200 apiece (so $800 total)! So I say you shouldn't be encouraging them to be cheapskates sacrificing electrical integrity for just pennies! So I totally understand what ur trying to do but plz just stop! Cuz I say some ppl can be insulted by you implying they're that stingy!

Filter Capacitor{S}:

⇒Working EMF ≥ 50V
⇒Surge EMF ≥ 65V

OVP(left) Zener transient suppressor:
Function: Preclusion of filter capacitor abuse corollary to EMF up-swings during near maximum output EMF operation.

HP I have better idea! Why not just use filter caps with working voltage rating above maximum open circuit output?

 

ATTN: @Aleph(0)

Please be advised that I anticipate response to your post ASAP (within a few hours) -- In the meantime you've more pressing matters to sort -- It seems @Ryan Jones has nicked your head in the name of bigger and better proto-board projects!



Golly!

TTFN
HP

 

HP I say even though circuit is basically like just a ballsy model railroad PSU you're being totally too optimistic abt newbies, as usual!

But then positively rank amateurs fall outside our target demographic...

Variac (variable auto-transformer):
Function: to provide continuously adjustable sinusoidal drive to the step-down transformer

HP I say anybody who doesn't already know that is in totally the wrong place!

And I would venture that clarity is not uncommonly augmented via statement of the obvious... Then too the term 'Variac' may not be in universal usage?...

So for ppl who need more detail on that here's what you need to do:

◊Remove Xfmr bunting to expose top winding (which is original primary that will now be secondary).

◊Find electrical center of winding by noting null-point from ends while other winding is energized (by just a few volts for safety).

◊Cut winding exactly at null point and unwrap each new inside end one turn so now new secondary winding is two windings which I'll just call windings _A_ and _B_.

◊Connect new secondary windings in electrical parallel by connecting outside end of Wdg A to inside end of Wdg B and inside end of Wdg A to outside end of Wdg B.

◊So stepped down output is taken from across windings!

Sincere thanks for that! -- While I maintain my dubiety as regards composition of a tutorial upon so pedestrian (and peripheral) a topic as linear LV PSU construction - I tend to concur with your view that the 'nuances' of power transformer modification might well be lost upon the 'magnetically challenged'...

Note that while an arrangement of four discrete industrial rectifiers is strongly recommended - A significantly less costly 'off the shelf' potted module exhibiting an I(fwd) Spec ≥ 30A (continuous) will suffice...

HP Sry but that's just lame! Cuz industrial rectifiers like those from Alegretti only cost like $200 apiece (so $800 total)! So I say you shouldn't be encouraging them to be cheapskates sacrificing electrical integrity for just pennies!

You may rest assured that you're preaching to the choir! -- Sadly, 'penny wise - pound foolish' is the way of the world - Even --so experience has taught me-- among such rarefied ranks as EHT enthusiasts

HP I have better idea! Why not just use filter caps with working voltage rating above maximum open circuit output?

It has long been my observation that 'non-solid electrolytics' featuring nominal capacitances much greater than 20 millifarads must needs frequently approach their maximum working EMF is dielectric integrity to be maintained...

Very best regards
HP

 

HP major tnx! So just for now we need two favors from you:

◊Plz copy contents of post 1362 to public view on ur blog.

◊Plz decide how you want to present inductor construction/magnetics primer and just post it! Now HP don't you dare put that back on me cuz you already disagreed with my approach so now it's totally your call!

Sincere thanks for that! -- While I maintain my dubiety as regards composition of a tutorial upon so pedestrian (and peripheral) a topic as linear LV PSU construction - I tend to concur with your view that the 'nuances' of power transformer modification might well be lost upon the 'magnetically challenged'...

HP It's totally like you said:

I would venture that clarity is not uncommonly augmented via statement of the obvious...

 

In the meantime you've more pressing matters to sort -- It seems @Ryan Jones has nicked your head in the name of bigger and better proto-board projects!

HP now I'm saying more than ever front page is a pain in the neck!

 

HP major tnx! So just for now we need two favors from you:

◊Plz copy contents of post 1362 to public view on ur blog.

Will do - pending 'proofing' and 'polishing'!

◊Plz decide how you want to present inductor construction/magnetics primer and just post it!

With pleasure! - The very instant, that is, that I descry the merest vestige of your long-overdue alpha-three report (Spec: in regards to assignment of the redesigned NR-Royer test driver)...

Remember this?

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

Impatiently tapping fingers!

you already disagreed with my approach so now it's totally your call!

Now who does that sound like?!

Best regards
HP

 

BTW Theodora! Since tagging your known UNs on here doesn't work I say either you aren't registered or you need to publicly post your AAC UN on this thread and start participating here ASAP! Theodora since you are on core development team I say your membership on here is NOT optional! So sry for public shaming but I'm totally tired of ppl making things more difficult with silly foot dragging!

Uh huh! You bet! Well that was fun! I just burned two hours of my miserable life bouncing between this wicked vpn's GB and DE servers no joy from ether! Glory be to my gmail session running on your notebook! Well I'm in! So you can have your pavilion back! Please! It's drawing flies!
So you need me to do exactly what? A report? Yea well the jerks are having luck with the test oscillator using HP's choke and I'm unqualified to answer most of their questions. Now there's a point in need of action! HP has to face facts! You know that "collaborative effort" or not they're more like her worshipful followers than students! Time for her to take the initiative and lead from the front! And oh yeah! @Aleph(0) may I address you by your first name on this list? You know most people trying to follow this don't know you as Aleph and it's causing confusion?

Anyone trying to register with AAC via Zenmate this is what finally worked for me
1 Disable flash
2 Disable all ad blocking and antitracking plugins to fill out and submit registration.
3 Activate your account through a separate device logged in to your email.
4 Put your avatar in jpeg format for upload.

 

Oh yeah! You can ignore my last e. I found "blue mode"

 

Well hey @theodoravain many, many sincere thanks for joining! -- I'm certain that the Alpha team and AAC members following this thread will greatly appreciate 'hearing' all sides of the conversation (ahem.. when we somehow mange on-topic content, that is)...

So you need me to do exactly what? A report?

Correct! @Aleph(0) will give you the low-down

Yea well the jerks are having luck with the test oscillator using HP's choke

'Having luck' = Good Referring to the AT as 'Jerks' = unconstructive -- Especially for those unaccustomed to your 'wry' humor...

I'm unqualified to answer most of their questions.

I respectfully disagree

HP has to face facts! You know that "collaborative effort" or not they're more like her worshipful followers than students!

And I would say EHT (i.e. 'high voltage', if you must) topics tend to enjoy a 'cult following' -- thus it's nothing to do with me and everything to do with the subject! - Which is precisely as it should be!

Time for her to take the initiative and lead from the front!

Touché! -- Please be advised that I am working on it (i.e. [to the extent possible] 'clearing my desk' of 'outside' responsibilities) know also that your participation (on this thread) will be of immense help!

Again - Very pleased to see you 'here'! As I understood her 'broadcast' @Aleph(0) should 'check in' sometime today (Wednesday)...

Very best regards
HP

 

@theodoravain -- Please 'field' a consensus of AT participants as regards the nature of and/or desire for a 'magnetics discussion' at this point - then post the results here... To put a 'finer point' upon it, are they indeed desirous of a primer at this early juncture? Or does their interest owe merely to 'curiosity' as regards parameter selection/determination (Re: my construction example/suggestion)? --- Granting the latter, please rest assured that a comprehensive treatment is planed as part of the driver design tutorial...

FYI I may be absent prior to Saturday (Mar 24) - howbeit I expect @Aleph(0) to return to posting later this evening (or early Thursday AM {UTC -5})

With grateful regards, again, many thanks!
HP

 

@theodoravain -- Please 'field' a consensus of AT participants as regards the nature of and/or desire for a 'magnetics discussion' at this point - then post the results here...

Yeah, ok fine. It's on tomorrow's GoToMeeting agenda.

Especially for those unaccustomed to your 'wry' humor...

Who's laughing?

Please be advised that I am working on it (i.e. [to the extent possible] 'clearing my desk' of 'outside' responsibilities)

Don't strain anything you plan to use

I expect @Aleph(0) to return to posting later this evening (or early Thursday AM {UTC -5})

Friday AM? Yeah well.. I'm not going anywhere.

Granting the latter, please rest assured that a comprehensive treatment is planed as part of the driver design tutorial...

We should live so long!

Well hey @theodoravain many, many sincere thanks for joining!

Blame that on @Aleph(0) 's hissy fit.

Very pleased to see you 'here'!

I wonder?

 

Re: login diffaculties...

@theodoravain -- Please give it another try -- FWIW @Aleph(0) had the same difficulty awhile back....

Good luck
HP

 

Hi, Theo -- Please be advised that I've reported your difficulty to the feedback fourm HERE -- Please keep trying and if sucessful post a followup to the linked thread in feedback...

Best regards
HP

 

Hi, Theo -- Please be advised that I've reported your difficulty to the feedback fourm HERE -- Please keep trying and if sucessful post a followup to the linked thread in feedback...

Best regards
HP

Been there, done that.

FWIW @Aleph(0) had the same difficulty awhile back....

Yeah! I know! And the same solution!

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

Was that tidbit of intelligence a share too far? Or were you withholding a "spoiler"?

 

Glory be to my gmail session running on your notebook!

Theodora tnx I'm glad it helped

Well I'm in! So you can have your pavilion back! Please! It's drawing flies!

Theodora Being serious we like them cuz even though XP is long in tooth FF ESR and all privacy plugins totally still work!

So you need me to do exactly what?

Yeah, ok fine. It's on tomorrow's GoToMeeting agenda.

So I say we just wait for that data then present it here in digested form!

I'm unqualified to answer most of their questions.

Theodora BS! Like you never let me forget I called you lazy and stupid on post somewhere way back on this thread which was totally wrong cuz you're not stupid! But lazy is other matter!

@Aleph(0) may I address you by your first name on this list? You know most people trying to follow this don't know you as Aleph and it's causing confusion?

Theodora ok since you basically had to give your autobiography to register on here that's fair enough! So to prevent misunderstandings I'll just dox my first name myself so it's Julie but I still prefer being called Aleph on here outside of _tutorial business_!

Anyone trying to register with AAC via Zenmate this is what finally worked for me
1 Disable flash
2 Disable all ad blocking and antitracking plugins to fill out and submit registration.
3 Activate your account through a separate device logged in to your email.
4 Put your avatar in jpeg format for upload.

Theodora tnx! I'll just cc that to Babs so anyone else wanting to sign-up on here through Leaseweb sees it!

Theodora now I'm going to tell you something! Since I'm totally in glass house cuz of my like _goody two shoes Fleur Bennett routine_ I can't rip on your _cynical bad girl_ persona! So even though persona won't let you acknowledge gratitude I still want you to hear that we're vry happy you decided to join up and help us out in person! So huge thanks!

Edited for content by Aleph(0) at 3/22/18 - 8:21 UTC-5