Please note -- In addition to attachment of images - the contents of this post have changed significantly from its initial 'incarnation' -- thank you!

To the team and all interested parties: I believe I've found an acceptable EHT potting solution sans requirement of vacuum pumps/chambers or dielectric gasses --- You may expect a detailed, illustrated description of said process (posted here) as soon as I find time for thorough 'in vivo' evaluation of same! (another week to 10 days 'oughta' do it)

To all interested/concerned parties:
In response to your inquires please be advised that said process requires nothing more than an 'electric skillet', a 500 VAR variac and, ideally, a 500 VAR ferroresonant (Spec: 'constant voltage') transformer (please see "Required Equipment Notes" 'further down' this post).

Please be advised that the manufacturer-supplied thermostat is unacceptable in the application under discussion (for its wide 'hysteresis'/full on-off thermal regulation scheme) -- That said, I 'second' @Aleph(0)'s recommendation that said device remain 'in-circuit' as an over-temp 'failsafe':

connect variac 2 skillet through its t-stat set on like 180°C (so abt 360°F) as failsafe! That way if like u say _stuff happens_ only loss will be wax (cuz of contamination with carbon flecks cuz of charring over resistor area) which I say is way better than burning wax and molten Al!

---Quotation edited for 'typo'---

Arrangement of resources/components:
Mains → ferroresonant transformer → Variac → thermostat (supplied with skillet) set for ≈ 180°C → Skillet


FYI -- Below is a preliminary 'step-by-step' (subject to amendment based upon user feedback, etc...)

1) Adjust the variac for a 'closed pan' temperature of 100°C at its warmest point(s) 60 minutes following adjustment. -- Record variac position.

2) Adjust variac such that the skillet attains an 'open pan' temp of 170°C at its warmest point(s) 60 minutes following adjustment.

3) Introduce the 'wax' slabs to the skillet heated as described in step #2 (above).

4) Process the 'wax' via 'holding' same at a temperature of no less than 160°C nor greater than 170°C ('open pan') for a period of three hours.

5) Cover the skillet then adjust the variac to the position corresponding to a temperature of 100°C (as determined and documented in step #1 above)

6) Check the wax at 30 minute intervals for a temperature ≥ 95°C but ≤ 105°C (whereupon it is ready for application as an insulation-only potting compound).

A note on fire safety.
While overheating is unlikely using the described scheme - 'stuff' happens! -- Please do not leave the described apparatus unattended! Additionally, ready availability of 'class B' fire-fighting equipment is highly recommended ('dry chemical' will work but CO2, properly applied, is much less 'messy'/damaging)...

Of course I don't expect anyone to 'stand guard' over the several hours' long process -- merely to keep it in view - This does not mean via 'WIFI cams' and their ilk (all of which have a 'proclivity' for 'silently' 'freezing' and thus presenting a 'stale' image of the monitored scene)... Note: although --as pointed out by @Aleph(0) -- 'tricks' may be employed to verify image currency, it is my stance that the demands of fire safety require line-of-sight operator presence -- My $.02 plus, perhaps, the replacement cost of your building! -- your call!

Notes Re: 'Required equipment'
1) Please be advised that 'brand-spanking-new' 12" electric skillets featuring 'easy pour corners' (e.g. Presto model 07117) are quite satisfactory for these purposes and almost free! --- Please use a new (i.e. unused) appliance!

2) A full-wave 'phase-control' circuit may be substituted for the variac.

FWIW I concur with @Aleph(0)'s observation quoted immediately below:

So just for ppl wanting 2 do it on the cheap, required pwr is 500W MAX so since element is pure resistive load just a 500VA FR transformer with standard 600W light dimmer for phase ctrl will totally be enough!

3) The ferroresonant transformer --while strongly recommended-- may be omitted where mains EMF excursion is confined to ≤ ±5% 'nominal' (e.g. certain 'secondary networks', etc)...

Please note that the CVT (Constant 'Voltage' Transformer) and variac shown below are significantly 'over applied' to this application! I apologize that I hadn't sufficient leisure time to 'rifle' my stock for more appropriate 'photographic subjects' --- Even so - it is my belief (hope?) that the images will prove useful in that more appropriate (i.e. lower-capacity) devices affect rather similar 'form-factors' and, hence, physical appearance save for proportionately reduced physical dimensions.

Equipment 'line-up' -- Left to right:
1) 750 VAR CVT (Note that a 500 VAR CVT is wholly acceptable!)
2) 100A @120V/240V Variac (Note that a 5A @120V variac is wholly acceptable!)
3) The recommended electric skillet purchased new on-line for Ca. $40 (USD) inclusive of shipping (lid and thermostat/power-cord not shown).

CVT Detail:

Variac Detail

Electric skillet detail -- Note the integral 'pour spout' (bottom corner as imaged):

Also I say is good idea to put ionization (but definitely not totally WORTHELESS photoelectric!) smoke detector above pan!

Agreed and agreed!

Or a slow cooker could be used.

So anyhow HUGE tnx for suggestion cuz if skillet doesn't work out we'll definitely be investigating your _Crock Pot_ idea!

Absolutely! -- Should my 'electric skillet approach' turn out a 'crack-pot notion' -- @shortbus' 'Crock-Pot suggestion' will most certainly prove a worthy Rival (lame puns intended -- Yeah, I know! But hey -- it's past 5:00 AM here)
In all seriousness - many sincere thanks @shortbus! -- For its several advantages, your suggestion will likely be adopted should adjustment of skillet temps prove excessively critical/'fiddlesome'...

@Hypatia's Protege just to say looking on your blog there's problem with _group pic_ of skillet potting equipment cuz of fringe on barrier booth curtain causing long λ filter artifact on upper left!

Corrected (i.e. re-imaged) -- Thanks!

Also I say instead of putting pix on separate post you can just delete post 1187 and repost it in new post with pix attached!

Two points:
1) Surly you mean post #1817!?
2) Never-ever delete posts! (said action 'messes up' references to subsequent posts! -- Your advice will be taken and post 1817 will be 'cleared' but retained as a 'place holder' following submission of this post.


@Aleph(0) @theodoravain and anyone who cares...

Below is the latest non-simulation draft of the LV_PSU soft-Start system... Proofing/feedback will be greatly appreciated!

Please note:
1) Modules are not yet 'bordered'.
2) The quad-LED 'chains' are packaged as single piece lamps.
3) Owing to ocasionaly 'funky' timer operation when K1 is powered through R_Bal, I have abandoned the 'elaborate' ballast-resistor/TCO arrangement in favor of a straight-forward line-interruption scheme.

Very best regards
HP

 

we'll definitely be investigating your _Crock Pot_ idea!

That's just one of many "crack pot ideas" I've had in this thread. Seems like you're having spelling problems again.

 

Below is the latest non-simulation draft of the LV_PSU soft-Start system... Proofing/feedback will be greatly appreciated!

HP I say only obvious problem is u forgot to specify value for R18 (which is bal for _pwr on led lamp_). Also 2b complete I say u need to specify color of _Ballast On_ and _Pwr On_ lamps cuz, like u know, different color LEDs usually have different VFs!

Also what is actual voltage on cathodes of D4 and D5? So o/c if winding was really 12V RMS, rectified & filtered output would max out at abt 17V DC. But cuz those type of xfmrs usually have like 20% higher than rated secondary voltage I totally wouldn't be surprised at all if rectified voltage is like 20V!

 

That's just one of many "crack pot ideas" I've had in this thread. Seems like you're having spelling problems again.

Shortbus since I'm not 100% sure UR just joking here's disclaimer:

_Crock Pot_ is brand name of slow cookers which are product of manufacturer named _Rival_ So HP was just having fun with wordplay:

Should my 'electric skillet approach' turn out a 'crack-pot notion' -- @shortbus' 'Crock-Pot suggestion' will most certainly prove a worthy Rival (lame puns intended)

So being serious we BOTH think slow cooker is excellent idea which we'll definitely be looking into if there's any problems with skillet at all!

 

_Crock Pot_ is brand name of slow cookers which are product of manufacturer named _Rival_ So HP was just having fun with wordplay:

... even I got the joke ... I seriously doubt shortbus missed it ...

 

... even I got the joke ... I seriously doubt shortbus missed it ...

Cmartinez TNX! I know sometimes I just need 2 relax!

 

! So anyhow only problem is it doesen't get hot enough for wax cleaning phase

Again with the cleaning of a product? What are you thinking will come out of a FDA regulated product that is approved for food use, that is going to hurt electrical components?

Shortbus since I'm not 100% sure UR just joking here's disclaimer:

_Crock Pot_ is brand name of slow cookers which are product of manufacturer named _Rival_ So HP was just having fun with wordplay:

I posted the answer to you before reading HP's post. I was again having fun with word play, while exploiting the spelling of some things you have posted in the past.

 

Also 2b complete I say u need to specify color of _Ballast On_ and _Pwr On_ lamps cuz, like u know, different color LEDs usually have different VFs!

Indeed! - Pursuant to your suggestion, I've attached the 'data sheet' applicable to the devices under discussion (to this post) and will attach same to the corresponding blog entry upon completion.

Note:
The Power-On (green) lamp PN = MU02-5202
The Ballast-Active (red) lamp PN = MU02-2201

Please note: Pursuant to enhanced power source versatility, the modules do not provide internal connection of their constituent LEDs (to wit: the cathode and anode leads of each LED are brought out of the module - ergo the specifications apply to each LED regarded as a discrete device.

Also what is actual voltage on cathodes of D4 and D5? So o/c if winding was really 12V RMS, rectified & filtered output would max out at abt 17V DC. But cuz those type of xfmrs usually have like 20% higher than rated secondary voltage I totally wouldn't be surprised at all if rectified voltage is like 20V!

---Emphasis Added---

Very good! -- As it turns out the pre-regulation EMF (i.e. E[C5]) ≈ 19V± 200mV under all load-circuitry states

u forgot to specify value for R18 (which is bal for _pwr on led lamp_).

Thank you for spotting that! -- Short answer R[R18]= 370Ω -- to be documented upon the next draft...

Elaboration:
1) A green module (Specifically MU02-5202) will be used as the 'Power On' indicator.

2) The datasheet specifies nominal E[fwd]=2.21V @20mA -- My examination of several units from various lots indicates E[fwd]≈2.25V @30mA (which being absolute maximum I[fwd_continuous])

3) Maximum visibility consistent with reasonable lamp MTBF dictates operating current consistent with the inequality: 25mA ≤ I[fwd] < 30mA --- Hence I[fwd_ideal] is deemed ≈ 27.5mA

Thus, for a series arrangement of the four integral LEDs:
Rb=(Vcc-4*E[fwd])/I[fwd_ideal] = (19 -4*2.25)/27.5mA=363.64Ω ≈ 370Ω (i.e. 220Ω+150Ω).

Again with the cleaning of a product? What are you thinking will come out...

Succinctly: Moisture and trapped/dissolved gasses -- Additionally, said thermal processing 'hardens' the 'wax' via volatilization of lower boiling/trace low boiling fractions...

As a point of interest, although hydrocarbon 'waxes' exhibit markedly lower hygroscopicity than typical of (HC) oils -- a surprising amount of 'moisture' is, nonetheless, present in the commercial product...

But to your 'broader' question:

a FDA regulated product that is approved for food use, that is going to hurt electrical components?

That a substance (or, rather, concentration thereof) 'qualifies' as permissible - indeed, even desirable- in food and/or pharmaceutical products is hardly an indication of its applicability to other areas!

As an example, please consider the employment of (thermally unstable) tocopherols as 'stratifying agents' in pharmaceutical (USP) grade 'mineral oil' (and, not uncommonly, food-grade (FCC) triglyceride oils)...

Come to that, a pleasingly flavored NaCl+H2O solution constitutes a fine dish of soup -- all the while an appalling electrical potting fluid!

I know sometimes I just need 2 relax

You don't say?!

Very best regards
HP

 

employment of (thermally unstable) tocopherols as 'stratifying agents' in pharmaceutical (USP) grade 'mineral oil'

HP o/c I know ur using accepted _language_ but I say is funny how what they call _stratifying agents_ are really anti-stratifying agents! So I say it's perfect example of institutionalization of lazy speech (so in this case for _stratification control agent_). All the same as convention of capital C on Calorie implying factor of 1,000 so 1 Calorie = 1 kcal! Also think on how inflammable = flammable even though it sounds like it should mean nonflammable (or that substance has like overzealous granulocytes?)

So being serious I'm not _nitpicking_ just saying words can be vry important and evolving lexicon needs 2 respect that! Cuz like ur always saying: _language is the dance partner that brung us, as a species _ !

I posted the answer to you before reading HP's post. I was again having fun with word play, while exploiting the spelling of some things you have posted in the past.

Shortbus tnx! It was just my phobia of being misunderstood making me _disclaim_ even though I knew it prolly wasn't necessary.

@Hypatia's Protege so calculating I(f ) of _ballast active_ light based on knows:

◊Vcc=9V (which is voltage of regulated rail) which I say is valid assumption for voltage across led+R13 ckt cuz based on drive ckt, Q7 gets totally saturated).

◊Rb (which is R13)=90Ω (from your schematic).
◊From datasheet V(f) for red leds ≈ 1.7V each so 6.8V drop in series.

So I(f) of lamp = (9-6.8)/90 which is 24.444mA.

HP so anyhow point of this is just 2 say since according to datasheet leds have peak I(f) rating of 60mA and also since _ballast active_ lamp is only on for like 500ms after powerup and 1sec max during _Vcc collapse_ after pwr off u can prolly get away with higher I(f) (of like 50mA) if u need better viability visibility!

Also why do u need redundant low power _ballast active_ led (D7) on soft start board?

 

{Re: the 'Ballast-Active' indicator:

So I(f) of lamp = (9-6.8)/90 which is 24.444mA.

Once again, very good! Design I[fwd_target] = 25mA -- I daresay you've the makings of a 'mean' reverse-engineer if so minded!

HP so anyhow point of this is just 2 say since according to datasheet leds have peak I(f) rating of 60mA and also since _ballast active_ lamp is only on for like 500ms after powerup and 1sec max during _Vcc collapse_ after pwr off u can prolly get away with higher I(f) (of like 50mA) if u need better viability!

---Emphasis Added---

Assuming _visibility_{} was the intention of the emphasized text:

Annoyingly, optical output plateaus at I[fwd] ≈ 25mA - But then --glory be to red diodes' high degree of luminous efficiency-- 'tis more than sufficient

Also why do u need redundant low power _ballast active_ led (D7) on soft start board?

'Catoptrophobe friendliness' - To wit: Said convenience obviates requirement of a 'front panel view' during adjustment



Very best regards
HP

 

Catoptrophobe

Did you mean to use that word? Or did you mean to use "Spectrophobe"?

 

Catoptrophobe

... have mercy!

Any relationship to catoptromancy?

 

... have mercy!

Any relationship to catoptromancy?

How about catastrophe? The reading of this thread.

 

How about catastrophe? The reading of this thread.

Or, perhaps ... cathartic ... as in: "a medicine that causes the bowels to be purged" ...

 

Assuming _visibility_ was the intention of the emphasized text:

HP I know I definitely need to be more conscientious abt proofreading but I also say Mozilla owns part of blame cuz auto-speller has been butt of jokes for years and they don't even try 2 improve it!

I daresay you've the makings of a 'mean' reverse-engineer if so minded!

HP u know that's true but not just cuz I know Ohm's law? Otherwise ur saying I should get job driving locomotive in reverse? Which I say would be stiffer fine than being southbound in northbound lane of expressway!

Annoyingly, optical output plateaus at I[fwd] ≈ 25mA

So then _thermal output_ starts exponential climb? HP I definitely know that _symptom_ It's exactly like u say _all disciplines are essentially the same, only the words change_

'Catoptrophobe friendliness' - To wit: Said convenience obviates requirement of a 'front panel view' during adjustment

HP that totally reminds me of adjusting _dynamic convergence_ on your antique TVs cuz I needed 2 hassle with mirror 2 see what I was doing! Tnx for memories NOT!

So anyhow for soft start ckt couldn't u just go by clicking of contactor 2 know when ballast duration and line freq latency settings are correct?

Did you mean to use that word? Or did you mean to use "Spectrophobe"?

Shortbus I say only type of _spirits_ in this whole series are from constant delays driving readers to drink! But speaking just for HP and me we're definitely not t-total!

Any relationship to catoptromancy?

Cmartinez I say YES since it's all _done with mirrors_

How about catastrophe? The reading of this thread.

Shortbus I say better thread than tutorials! So _squishing bugs_ b4 they get into tutorial is a major purpose of this thread!

Or, perhaps ... cathartic ... as in: "a medicine that causes the bowels to be purged" ...

Cmartinez I say ur close cuz it's like AYBS character Mr. Rumbold's definition of _think tank_ which was: _a venue where ppl chew over a problem then bring up a solution_

So anyhow u guys can joke but I agree with HP that not having to fiddle with mirror during setup is definitely worth price of extra LED and 1kΩ resistor! So I know it seems like we're being way too elaborate for just big clunky unregulated linear PSU but I say (outside of fine arts) function comes b4 form every time! Cuz once it's built, we just want it to work reliably so we can stay focused on more _cerebral_ aspects of series!

 

... have mercy!

Been waiting for the bus all day?

Any relationship to catoptromancy?

Cmartinez I say YES since it's all _done with mirrors_

But speaking just for HP and me we're definitely not t-total!

Scrying in your beer, Aleph?

TTFN
HP

 

So anyhow for soft start ckt couldn't u just go by clicking of contactor 2 know when ballast duration and line freq latency settings are correct?

Preclusion of over-current damage requires that the inrush-protected circuitry remains disconnected/ballasted pending attainment of correct 'soft-start' adjustment -- It is a simpler matter to merely disable the contactor (i.e. open its actuator-coil circuit) than to 'meddle' with its high-current 'output' connection ---- Disabled contactors don't 'click'

Very best regards
HP

 

HP Sry cuz I don't have time now for full feedback but right now we need u to officially settle petty confusion abt term for silicone cladding separating from HV winding as result of overheating with heat gun! So I totally agree with you calling it _abruption_ cuz it describes basically spontaneous separation w/o cutting, scraping or direct traction as factor! But Lori keeps insisting on calling it _avulsion_ which I say is wrong when it's not caused by direct mechanical force! So I could totally accept separation caused by chemical reaction or action of solvent being called _avulsion_ but that's not how it happens cuz it's just heat causing totally reversible non-chemical change to silicone! So imo release of materials caused by changes in volume (or whatever) and so interface dynamics is just abruption!

So as example of what I'm saying: scraping hoarfrost off windshield is avulsion. But running defroster causing frost to slough off (cuz of state change at H2O/Glass interface) is abruption! Also I say _delamination_ can be either depending on circumstance!

HP So I'm sry abt pettiness of all this but like u say words are VRY important to everything including comprehension of subject matter!

 

we need u to officially settle petty confusion abt term for silicone cladding separating from HV winding as result of overheating with heat gun! So I totally agree with you calling it _abruption_ cuz it describes basically spontaneous separation w/o cutting, scraping or direct traction as factor!

Succinctly, within the context of failure analysis -- 'avulsion' describes a mode of damage whereas 'abruption' is descriptive of a failure mode --- IOW Agreed!

So as example of what I'm saying: scraping hoarfrost off windshield is avulsion. But running defroster causing frost to slough off (cuz of state change at H2O/Glass interface) is abruption! Also I say _delamination_ can be either depending on circumstance!

While the above aptly describes said processes -- it ignores the narrow context to which the terms were applied (to wit: damage/failure --as opposed to-- desired alteration)...

But Lori keeps insisting...

Should Lori, or, for that matter, any interested party, desire a 'louder' voice as regards proofing, suggestions, etc... They may jolly well register with AAC and participate here! -- I've scant patience with team members excusing their non-participation here on 'privacy grounds' all the while maintaining a running 'stream of consciousness' on social media sans the least vestige of anonymity!

Best regards
HP

 

So I totally agree with you calling it _abruption_ cuz it describes basically spontaneous separation w/o cutting, scraping or direct traction as factor! But Lori keeps insisting on calling it _avulsion_ which I say is wrong when it's not caused by direct mechanical force!

With all of the time and effort put into this, that is the most pressing topic of discussion? At the beginning of this I really thought it was a serious topic and project. But as time goes by it seems to be less of one.

They may jolly well register with AAC and participate here!

Are any of these interested parties named, "Snuffleupagus", by chance?