# EHT power supply design and construction

#### Hypatia's Protege

Joined Mar 1, 2015
3,226
@Aleph(0) -- Please mail a raw copy of post #609!!! - Thank you!

#### Aleph(0)

Joined Mar 14, 2015
597
HP you need to chill! It's done! So now you have to finish tutorial so I can give it final check

#### Hypatia's Protege

Joined Mar 1, 2015
3,226
HP you need to chill! It's done! So now you have to finish tutorial so I can give it final check
I'll get at it ASAP -- Many, many thanks!

Best regards
HP

#### Hypatia's Protege

Joined Mar 1, 2015
3,226
<<<<Latest revision @ post #698>>>
LOPT preparation tutorial development
Last action @ 9/17/2016 --- 15:10 UTC

====Introduction====

Scope of series:

Central topics:
This tutorial is one in a (prospective) series with focus upon low ripple, medium current/power PSU solutions for radiography and other modest photon energy (≤ 2 MeV) particle accelerator applications - and, to a lesser extent, exploration of certain 'current intensive' electrostatic phenomena (e.g. electret photography, electret formation, electrokinesis, establishment of electrostatically 'cordoned' (atmospheric) pressure gradients, high volume ion-flow systems, etc...

Peripheral and extraneous topics:
While everyone is welcome to view and post questions (within the confines of this site's TOS/UA) - Please be advised that those having interests confined to the following topics/applications will not likely find this series particularly useful (owing to the availability of significantly less 'labor-intensive' solutions to same):

--'Pedestrian' and 'Quasi'/'Peri'-EHT applications:
(e.g. CRTs, PMTs/Image tubes, Gas discharge devices, lasers, 'negative ion air purifiers', TC primary drivers, GM tubes, etc...)
--Low current demonstration topics (e.g. 'Lifters', 'Jacob's Ladders', 'Plasma Spheres', 'Kirlian photography', 'Ion Motors', etc...)
--Capacitor discharge demonstration: (e.g. 'Quarter Shrinkers'/'Can Crushers', 'Rail/Coil Guns', 'EMP generators', electrical weapons, etc...)

Please be advised that site policy prohibits my response to most inquiries coming under the latter category...
=================================================

Scope of this tutorial
Provision of a minute, 'step by step' procedure for modification of 'heavy duty'
AC LOPTs for 'serious' EHT application/research...

Said procedure having the following principal goals:
-- Improvement of insulation integrity via removal of auxiliary windings coaxial to the EHT winding.
-- Enhancement of versatility via electrical 'floating' of the EHT winding.
-- Appropriate adjustment of reluctance gaps.

The desirability of LOPTs:

Of the commonly available magnetic components applicable to low through medium power EHT production, the LOPT offers the advantages of relatively high power intermittent operation (several hundred to >1kW per transformer) and useful continuous power operation (to Ca. 600 Watts each transformer under forced air cooling). Moreover, LOPTs' amenability to resonant (and, hence, sinusoidal) drive permits development of systems productive of highly desirable mean output EMFs (≈70% peak) as opposed to the rather low (< 1% through 5% 'spike' EMF) characteristic of flyback and similar pulse driven/energy storage topologies. Additionally, the inherent output symmetry attending resonant drive topologies facilitates implementation of effective external EMF 'multiplication' schemes.

Prominent among the LOPT's disadvantages are the common expedient of integral rectification/EMF multiplication circuitry and 'end point' grounding schemes --- While the former objection is readily addressed via judicious transformer selection, the latter requires minor 'reconstruction' - said procedure being the subject of this tutorial.

A few words regarding the unsuitability of DSTs and their ilk:
Principally:
1) Integral components electrically unsuited to general application.
2) Practical impossibility of modification for improved EHT winding to core insulation.

Re: point 1 (above) Although asymmetric drive may permit peak forward (and hence output) EMFs well in excess of the internal rectifiers' PIVs - such is, of course, inapplicable to 'filtered' or otherwise capacitively loaded schemes sans additional external rectifiers - moreover internal rectification greatly complicates cascading of multiple LOPTs for increased EMF and/or development of balanced output schemes...

Re: Point 2
(above)
'DC' LOPTs are constructed as indivisible units sans 'margin' for modification -- moreover (in the case of DSTs) the rectifiers are 'distributed' throughout the winding...

LOPT Selection:

Best regards
HP

#### Aleph(0)

Joined Mar 14, 2015
597
The real question is why would you even consider such a scheme?!
HP It's not my idea! I just wanted more than my opinion to convince Andy not to bother with it cuz I say one more electrical fire and Lisa will leave him for good! Then I'll have two big babies crying in their beer to console HP I can almost like being thought of as mad scientist but not so much a social worker!

$1,000 isn't going to break anyone! Probably not but I say it would back some ppl up a few squares and make them sit out a turn (ya there JC?) HP if you really want to get tutorial done this month you better get busy on unfinished disassembly instructions and closing cuz there's a lot of fiddly BS to do after that! HP I say tool addendum should be put in your blog and linked wherever hard to find tool is referenced in text? Also how abt instructions to build analog EHT voltmeter? Should that be put in addendum or be subject of mini-tutorial? #### Hypatia's Protege Joined Mar 1, 2015 3,226 cuz I say one more electrical fire and Lisa will leave him for good! FWIW I think it was her fortnight's prostration following his bright idea (pun intended!) of interior lighting via Hg vapor lamps minus their borosilicate bulbs that was the 'penultimate straw', as it were! -- IMNSHO photokeratitis has got to compare unfavorably with even infidelity as regards maintenance of 'connubial bliss' -- But yes! Those late-night fire calls have to take their toll as well! -- Sleep is somehow more restful granting reasonable expectation of seeing another day (Go figure) Dedicated to Lisa and Drew (Sorry, I can't resist) Probably not but I say it would back some ppl up a few squares and make them sit out a turn (ya there JC?)$1000 no -- loss of his online gaming console (Xbox?), however, would require crisis intervention followed by at least six month's inpatient psychiatric care

HP if you really want to get tutorial done this month you better get busy on unfinished disassembly instructions and closing cuz there's a lot of fiddly BS to do after that!
I'll be at it ASAP if not sooner!

HP I say tool addendum should be put in your blog and linked wherever hard to find tool is referenced in text?
Sounds like a plan!

Also how abt instructions to build analog EHT voltmeter? Should that be put in addendum or be subject of mini-tutorial?
Instruments intended for up to 250KV (DC) 'single ended' measurement are readily available and rather inexpensive (I'll post links later) -- That said, construction advice for balanced units may be warranted...

All the best
HP

Last edited:

#### Jazz2C

Joined May 27, 2016
52
@Jazz2C if you want to be a bona fide part of the EHT PSU effort - we need to hear from you HERE (as opposed to email/SMS, etc...)
Hp my interest in helping with the courses is totally genuine! It's just that I'm up to my ears with this that and t'other right now! I want to work out a schedule that allows me to devote at least an hour or so a week here but I can't make any promises at this point. But you have my word of honor that games aren't taking me away from anything!

#### Hypatia's Protege

Joined Mar 1, 2015
3,226
Hp my interest in helping with the courses is totally genuine! It's just that I'm up to my ears with this that and t'other right now! I want to work out a schedule that allows me to devote at least an hour or so a week here but I can't make any promises at this point. But you have my word of honor that games aren't taking me away from anything!
As stated on several occasions, I neither expect nor request that your activity on this thread in any way competes with your studies! -- quite the contrary! -- If, however, you wish to be part of the tutorial development team you'll need to 'carve out' some time from your leisure hours! -- Moreover your 'Who am I to correct HP' refrain isn't going to fly!

Sincerely, welcome back!

Best regards
HP

#### Hypatia's Protege

Joined Mar 1, 2015
3,226
@Aleph(0), @Jazz2C et al.

This is to advise you that I 'm working towards completion the tutorial (post #625) via 'edit' -- When you find a moment, proof-reading/feedback would be greatly appreciated!

Best regards
HP

#### Aleph(0)

Joined Mar 14, 2015
597
@Aleph(0), @Jazz2C et al.

This is to advise you that I 'm working towards completion the tutorial (post #625) via 'edit' -- When you find a moment, proof-reading/feedback would be greatly appreciated!

Best regards
HP
HP I'll proofread it when it's totally done cuz otherwise it never will be! For now I can just say that some ppl might get confused abt N-cm cuz Newtons are less familiar than force units which are also used for mass! Just saying. Anyhow I like how you finished the disassembly details so now it's just finishing the tutorial and doing the glossary and we're all set!

#### Aleph(0)

Joined Mar 14, 2015
597
HP did you see my actions on your AdvoSci physics forum regarding thread abt bobbing bird novelty? I say you should pull SuperMod status from idiot RynT_ _ _ cuz he's ignorant of basic principles and needlessly rude to posters! For example he said when air and water are same temp that bird gets energy from disassociation of water When any ordinary moron knows dTemp is just from evaporative cooling of wet fabric on beak! That's why I showed them it couldn't work when RH is too high or with novelties that expect water temp lower than air temp! HP I know you are open minded to some of Keely's ideas and all that but I also say Super Mods shouldn't ridicule newbies to push fringe ideas in favor of common sense! Anyhow I took the liberties of reinstating banned posters and putting lockout on Ryan's SM account until you sort it out Sry cuz I know you're busy enough already

#### Hypatia's Protege

Joined Mar 1, 2015
3,226
some ppl might get confused abt N-cm cuz Newtons are less familiar than force units which are also used for mass!
Then 'some people' require further study in the physical sciences! -- As stated upon many occasions I refuse to 'teach down' to anyone! While I'm sensitive to the inevitable confusion attending injudicious use of idioms, colloquialisms, etc. -- I assert that accepted terminology will pose no difficulty to those possessed of the fundamental cognitive 'prerequisites' for appreciation of the material offered here -- Please note that, as per your suggestion, I have eschewed 'rigorous' mathematical treatment (i.e. via analysis, vector algebra, etc. {Albeit that may need to change in future editions}) -- Hence the 'bar' is rather low as it stands -- let's not make it subterranean!

so now it's just finishing the tutorial and doing the glossary
No kidding?

HP did you see my actions on your AdvoSci physics forum regarding thread abt bobbing bird novelty? I say you should pull SuperMod status from idiot RynT_ _ _ cuz he's ignorant of basic principles and needlessly rude to posters! For example he said when air and water are same temp that bird gets energy from disassociation of water When any ordinary moron knows dTemp is just from evaporative cooling of wet fabric on beak! That's why I showed them it couldn't work when RH is too high or with novelties that expect water temp lower than air temp! HP I know you are open minded to some of Keely's ideas and all that but I also say Super Mods shouldn't ridicule newbies to push fringe ideas in favor of common sense! Anyhow I took the liberties of reinstating banned posters and putting lockout on Ryan's SM account until you sort it out Sry cuz I know you're busy enough already
ALEPH! While I have no objection to your described 'actions' nor argument with your concerns -- It does not , by any stretch of logic, bear discussion here!!!!

HP

#### Aleph(0)

Joined Mar 14, 2015
597
Hence the 'bar' is rather low as it stands -- let's not make it subterranean!
HP Ok I agree that's a good point!

No kidding?
HP That's uncalled for! Cuz I wasn't criticizing just saying we're almost done!

It does not , by any stretch of logic, bear discussion here!!!!
HP, Ryan is a total jerk that you shouldn't be worrying about! Last year when you were on vacation and he explained your absence by saying you committed suicide and ppl believed it cuz of his position as SuperMod you said he was on _thin ice_ and now this! HP I say just cuz he mods for free is no excuse for willful bad conduct! I mean being shot in the back is free too but nobody thinks its ok cuz it's free

HP I'm so sry my being on YOUR side angers you!

#### Hypatia's Protege

Joined Mar 1, 2015
3,226
HP I say just cuz he mods for free is no excuse for willful bad conduct!
No, not an excuse but... Let's put it this way - if you're willing to take it on yourself or wish to vouch for a personal acquaintance interested in the 'job' (complete, if desired, with compensation including benefits, etc...) -- then by all means show RT the 'door'! -- Get my point? --- I'd rather endure the known proclivities of a personal acquaintance ('gratis' or otherwise) than risk the vagaries of a 'web associate'! -- Agreed! RT is a lame practical joker (you will please pardon the redundancy) and an aggressive proselytizer as regards his 'pet theories' - but such represents the extent of his 'errancy' which is more than could reasonably be assumed of a 'promoted member' or otherwise 'web-only' acquaintance --- But then you seem to have matters in hand, so what's the problem?

Regarding -- Can it be? The tutorial?! (remember that?) -- Here's the deal: I will be scarce the next few days during which I will endeavor to (incrementally) complete the tutorial (Post #625) -- Although time will not likely permit detailed annotation of progress nor response to posts, PMs etc... during said time, I will, however, 'update' the 'Last Action time' header (at the 'top' of said post) as appropriate. -- Please rest assured that I will view any posts or PMs taging/addressing me in the interum...

SO... If all goes as expected my next post to this site will be by way of announcing completion of the [pen]ultimate draft (i.e. the final draft pending proofing)

All the best
HP