So this is just to explain that @Hypatia's Protege has some unexpected _distractions_ 2 deal with but totally expects 2b back first part of next week (Tuesday or Wednesday 4 sure!)

I'd suggest you give some consideration to using either steel hydraulic tube or pneumatic aluminum tube as vacuum chambers

I must have missed something in this. I thought the use of the vacuum chamber was to pull some kind of insulating compound into the repurposed LOPT? If so yours must be larger than any I've ever seen.

@cmartinez and @shortbus TNX! So just fyi use for vacuum chamber in our HV projects is mainly potting Vabar cascades which is basically this circuit except fed by resonant Royer Osc! Also since our PSU is _split supply_ we use two cascades w/ opposite polarity to ground. So schematic just shows positive _channel_ and actual circuit is a little more complicated cuz of HV divider resistors and compensation Caps for output regulation loop.

Anyhow for more context of pix u can look on thread HERE Now this is vry important 2 avoid confusion! Vabar cascade isn't related to Vabar coil at all! So even though they're prolly named after same person (like Tesla car vs Tesla coil) they're two totally different _animals_!

So anyhow abt cascade, Caps are like physically HUGE 1nF/50kV _doorknobs_ and 30kV/20mA diodes also need potting to prevent flashover!

Also HP totally promises to post pix of those components and phenolic (_bakelite_?) housing containers first thing when she's back! So it's just cuz of size of components and housings that we need big Vac chamber cuz flybacks don't need 2b potted at all beyond how EHT wdg is already dry-potted from factory!

Just so u know we're totally grateful for your suggestions and to discuss ideas for safer (than OmniJug) vac chamber cuz I say a _fragged_ reader can be a vry angry, totally disillusioned reader!

 

Vabar cascade

Making up words? Googling gets me nowhere on that?

 

Making up words? Googling gets me nowhere on that?

Shortbus I agree it's totally sad how it's getting 2 where all Google is good for anymore is tawdry celeb gossip and politics! Cuz that wasn't always so So anyhow I say that's just downside of _free market forces_ and like that So now it's like Sydney Smith could say: _What Google doesn't know would make a great book_

Anyhow Vabar cascade is vry similar to FW CW cascade (by which I mean full wave Cockroft-Walton cascade) except it doesn't need center-tapped xfmr and also if application can tolerate unidirectional DC path through diodes u can save cost of two input caps which also has advantage of lower xfmr to load impedance!

So in HP's diagrams (which I attached to post 1761) u can see it's actually just cascade using bridge rectifiers instead back to back half-wave cascades! So one way u can look on it is 2 say that Vabar cascade is to full-wave CW cascade what bridge rectifier is to tapped secondary FW rectifier in LV PSUs

So I also sent HP email asking her to post Ltspics .ASC for Vabar tripler (which is depicted in upper diagram attached on my last post) but since ppl almost never open attachments she says she can also post screenshots of simulation too!

Anyhow I say everything will be a lot clearer once @Hypatia's Protege uploads that and pix of components!

Making up words?

Shortbus, Vabar _multipliers_ are extensively mentioned in Audels and in early literature abt particle accelerators and like that So it's just that we totally insist on giving credit where it's due even to _obscure _ designs which in case of Vabar cascade is way better design than FW CW cascade! But like I'm saying in last post, it's not connected (npi) with Vabar coil (which is basically type of Odin coil) and also shouldn't be confused with Villard cascade which I say is just CW cascade by another name!

So anyhow, HP will be uping pix this week so u and @cmartinez (and anyone else is welcome too) can see dimensions to maybe help us out with potting solution for which we're VRY grateful!

 

But like I'm saying in last post, it's not connected (npi) with Vabar coil (which is basically type of Odin coil) and also shouldn't be confused with Villard cascade which I say is just CW cascade by another name!

Yet another new word to me, or a couple of them. The Oudin Coil(not Odin) I am familiar with, couldn't find any thing called a Vabar, just links and pictures of a, "Human Tesla Chakra Coil System", which looks kind of new age type of thing. What's next Akashic readings?

The Villard cascade is a new name for something else I knew of.

 

Yet another new word to me, or a couple of them. The Oudin Coil(not Odin) I am familiar with, couldn't find any thing called a Vabar

While I can vouch for 'Vabar' (cascade and coil) as well as 'Villard' --- I suspect 'Odin' is, indeed, a misspelling of 'Oudin' (what say ye, Aleph(0)?)...

What's next Akashic readings?

Truth be told I forsook my (um... 'pharmacologically assisted') visits to the 'Etheric Plane' somewhere --away back-- in the daze (sic) of my youth -- My closest approaches to same now consisting of 'junkets' via the able prose of FB Long, HP Lovecraft, AH Blackwood, et al

Well hey! --In all seriousness-- Please accept my sincere apologies for the (no-doubt) highly annoying (albeit genuinely unavoidable) delays --- Please rest assured that I will return sometime this week bearing images, over-due responses and much more!

Very best regards
HP

 

Truth be told I forsook my (um... 'pharmacologically assisted') visits to the 'Etheric Plane' somewhere --away back-- in the daze (sic) of my youth

Been there done that, and miss it.

 

Been there done that, and miss it.

A true 'child' of the 60's? -- Must have been a trip (double entendre intended!)

Very best regards
HP

 

A true 'child' of the 60's? -- Must have been a trip (double entendre intended!)

Very best regards
HP

Got into it later, the 70's. A disciple of sorts of Paul Stamets.

 

Please rest assured that I will return sometime this week bearing images, over-due responses and much more!

So - with no further ado

HP just to let u know we've totally been getting lots of requests 4u2 post diagram of WHOLE circuit including complete opto-isolating triac, EM contactor and ballast resistor! So anyhow I sent _broadcast_ saying that u aren't abt to model any more 3'rd party components (cuz of problem getting them imported to other ppl's installations) but consensus is that they just want to see whole picture for context (so they aren't asking for .asc of that, just schematic image)!

@Hypatia's Protege So abt _soft start_ circuit IMO it definitely needs two more features:

◊ Indication showing when ballast resistor is not bypassed!

◊Thermal cut-out fuse on ballast resistor in case soft start circuit fails leaving resistor in circuit with PSU loaded!

Thank you! -- Your suggestions are now included in the following 'schematic-only' draft:

I must have missed something in this. I thought the use of the vacuum chamber was to pull some kind of insulating compound into the repurposed LOPT? If so yours must be larger than any I've ever seen.

@cmartinez and @shortbus TNX! So just fyi use for vacuum chamber in our HV projects is mainly potting Vabar cascades which is basically this circuit except fed by resonant Royer Osc! Also since our PSU is _split supply_ we use two cascades w/ opposite polarity to ground. So schematic just shows positive _channel_ and actual circuit is a little more complicated cuz of HV divider resistors and compensation Caps for output regulation loop.

HP totally promises to post pix of those components and phenolic (_bakelite_?) housing containers first thing when she's back!

Here ya go!

Approximate dimensions (each vessel) = 22cm*19cm*7.5cm -- Note that it it highly desirable (even imperative) that the cascade for each channel be potted simultaneously! Hence, as a practical matter, granting 'allowance' for positioning forms/fasteners, the VC must accommodate a ≈ 22cm cube...

please be advised that it is our plan to 'gather' your contributions (past, present and future) to a blog entry (via the fora 'quote' feature such that your advice will remain verbatim and with full attribution) for linked reference under 'suggested alternatives' in appropriate tutorial passages -Subject to your item-by-item permission, of course!

@cmartinez @jpanhalt @MaxHeadRoom @shortbus @The Electrician

Please be advised that I have added your usernames to our reader feedback entry such that you may review your contributions in said 'context' -- Know that I've only begun to 'scratch the surface' as it were -- As I continue to review this (and related) threads I expect that much additional content will be added - Note also that members will be added to the 'viewers list' as their content is 'gathered' to the entry -- Please advise me (or any of my associates) should you wish your content removed, revised or to direct me to other content you feel may be appropriate...

Please note -- I've set the entry to 'private' (i.e. visible only to the content authors) as a courtesy to said providers pending review of their submissions. -- On my word! All users having content copied to (or whom are in any way referenced upon) said thread will be immediately added to the viewers list! -- Further to that - I will, upon request, happily add any genuinely interested members regardless of contribution ststus!

Very best regards
HP

 

@Hypatia's Protege diagram says _TCO cannot interrupt system during unballasted condition_
HP I get it cuz when contactor is closed softstart circuit is powered through ballast resistor! I say that's perfect cuz that way PSU doesn't get shutdown by _reflux_ heat still reaching surface of resistor right after resistor is bypassed! Also I like that TCO doesn't have to carry unballasted PSU current (so it's limited to like just 6A!) So just MWO TCO is totally good enough!

HP in diagram u said worst case TCO current = E(mains)/R(ballast) but I say being technical abt it worst case TCO current = [E(mains)/E(ballast)]+I(SoftStart circuit) but if ur not sweating the extra 200mA neither am I

HP just one more thing! In pic of Vabar components u show _low side_ resistors on Polyphos card but o/c they don't need 2b potted! So that doesn't help with size of vacuum chamber but it can make Varbar tank less crowded

 

diagram says _TCO cannot interrupt system during unballasted condition_
HP I get it cuz when contactor is closed softstart circuit is powered through ballast resistor!

--Better stated--

Should the TCO open while the contactor is closed - the contactor will remain closed owing to maintenance of excitation of the soft-start controller and the contactor's actuator coil via the ballast resistor -- A state that, for ease of reference, I shall hereafter term 'holding mode'....

Note also that, inasmuch as:
|Z_Soft-Start Controller| ≈ 1.8kΩ
|Z_Contactor Actuator coil| (paralleled by 'snubber', armature 'in') = 2.7kΩ

Therefor E_ballast(Effective) ≈ 2V (for a ballast dissapation ≈ 200mW during 'holding') -- assuring swift ballast cool-down/timely TCO reset.

Re: I(Soft-Start_Controller):

if ur not sweating the extra 200mA neither am I

--Emphasis added--

Where are you getting that ridiculous figure?! -- The controller (inclusive of its PSU but exclusive of the contactor actuator) draws no more than 70mA -- Recall that 'inrush phenomena' are inapplicable here inasmuch as 'holding' can occur only following power-up...

As an aside, the contactor actuator's inductance (and, hence, impedance) will be at maximum following deployment (owing to the armature's closure of the 'magnetic circuit' while at said position)

Very best regards
HP

 

Please note:

The novel connection of the TCO (such that worst-case TCO current ≈ 6A --as opposed to-- full system input current) was suggested by a third party who wishes to remain anonymous -- That said, I'm pleased to advise that he is a member of these fora and has participated on this thread - Many sincere thanks, sir!

Most sincerely
HP

 

do you plan to add a block diagram, a schematic of the complete circuit that you are developing?

it would greatly assist readers

 

Hp and Aleph, after seeing that this, the part needing vacuum impregnated, is in it's own box, why can't you do it with a vacuum impregnation bag? They do it for many molding operations using both carbon fiber and fiberglass parts.
Just one company out there selling them - https://www.fibreglast.com/product/...es-for-room-temp-applications/Learning_Center

 

John_2016 Tnx!

do you plan to add a block diagram, a schematic of the complete circuit that you are developing?

it would greatly assist readers

John_2016 We'll definitely be posting schematics, circuit descriptions and simulations (including netlists/subckts for components which aren't native to LtSpice' library) to tutorials and all construction projects! For now schematics are basically scattered through this thread but plz be careful to look just on latest revisions! So @Hypatia's Protege (who is basically in charge of what we're doing here) is in process of anchoring all those sort of resources to her blog and maintaining them there so ppl can know they're seeing latest versions!

So just to let u know our main subject is EHT power supplies (> 100kV at up to 20mA ) but right now we're bogged down with auxiliary equipment projects (like high current LV PSU and EHT meter) so unfortunately it's necessary cuz most ppl don't have that equipment and prefer 2 build than just buy it which is prolly just as well for LVPSU since it needs 2b specially designed to survive _EHT environment_ (by which I mean corona, high energy transients on input, intense, repetitive EMP and like that) plus being able to not just survive but actually supply huge transient current demand (sometimes into the low kAs) plus other _hardening_ features not available from commercial products. So putting it another way LVPSU can be thought on as adjustable electronic _LA battery_ with a little ripple as the acceptable trade off Also, just so u know, high current (like 200A) voltage regulators and remote activated contactors will be presented as separate _modules_ connected to output. So that way experimenters have maximum versatility

Now returning to point of your question, since at present we don't have like _central archive_ of schematics, circuit descriptions, and simulations we're definitely happy to answer any questions including posting diagrams of whatever you want to know abt our projects and series so plz just ask right here on this thread!

Also FWIW here's link to first Tutorial in series (under development) which is basically just utilitarian procedure for prepping TV flybacks (LOPTs) for higher power and voltage application. But intro basically gives _mission statement_ of series!

 

Hp and Aleph, after seeing that this, the part needing vacuum impregnated, is in it's own box, why can't you do it with a vacuum impregnation bag? They do it for many molding operations using both carbon fiber and fiberglass parts.
Just one company out there selling them - https://www.fibreglast.com/product/...es-for-room-temp-applications/Learning_Center

Shortbuz tnx! So I think there's misunderstanding (which could definitely be on my part). So we don't need vacuum for _impregnation_ of potted items by potting oil. What we need 2 do is dry, deaerate and remove low boiling fractions from potting oil. So basally process needs rigid chamber and lower pressure (like < 250μm Hg) than laminate processing equipment which mostly has lower limit of abt 10mbar (so abt 7500 μm Hg).

So huge tnx anyhow! And plz let me know if I'm misunderstanding u!

 

I haven't failed to notice that you and your people are willing to lay down the money for the purpose of this project, if the need for it becomes unavoidable.

Cmartinez thanks! That's definitely stance of core development team (which active on AAC fora are basically HP, Theo, JC and me) but we keep discovering that _all mighty buck_ is biggest single issue with readers So it totally sucks but we have to look on _economy_ with same weight as design criteria (except safety issues which are totally _non discretionary_!)

I'd suggest you give some consideration to using either steel hydraulic tube or pneumatic aluminum tube as vacuum chambers, which can be capped with specially made plates with grooves for o-rings machined in them. Remember I offered you my help in PM? I could help you design those plates, if you first choose the type and size of tube that you think would serve your purposes.

Cmartinez if we do need to take _high road_, Lexan (PC) or tempered glass would be best for at least one plate to allow visual observation of off-gassing potting oil. Now glass would be best cuz of way better thermal property so do u think that can be feasible for like 1500cm^2 end-plate?

A good supplier for said sort of tubes is www.scotindustries.com, I used their products a while back, and their prices were not so bad.

Cmartinex tnx! I'll let @Hypatia's Protege know to add that to your suggestion list in blog!

 

Cmartinez thanks! That's definitely stance of core development team (which active on AAC fora are basically HP, Theo, JC and me) but we keep discovering that _all mighty buck_ is biggest single issue with readers So it totally sucks but we have to look on _economy_ with same weight as design criteria (except safety issues which are totally _non discretionary_!)


Cmartinez if we do need to take _high road_, Lexan (PC) or tempered glass would be best for at least one plate to allow visual observation of off-gassing potting oil. Now glass would be best cuz of way better thermal property so do u think that can be feasible for like 1500cm^2 end-plate?


Cmartinex tnx! I'll let @Hypatia's Protege know to add that to your suggestion list in blog!

Can you post a sketch with the general geometry and dimensions of the part you need to vacuum-treat?

 

What we need 2 do is dry, deaerate and remove low boiling fractions from potting oil.

OK, but that to me makes no sense. Unless the oil is kept under vacuum while this unit is in use and storage and never moved, air and moisture will go back into it. Even pouring the oil from a vacuum system into it's final part of the unit will add air back into it.

 

Unless the oil is kept under vacuum while this unit is in use and storage and never moved, air and moisture will go back into it.

Wouldn't that depend on the design of the device's seal?