sometimes I think ppl reading it on here could be confused abt why it's in off topic forum?

My 2 cents: You have a nice, quiet corner to work in here without every noob that wanders by offering sophomoric noobie suggestions. It looks like that strategy is working. Slow as you are, you aren't being cluttered up with kibitzing. My opinion is, stay with what works. The ship isn't sinking so you don't need to jump overboard.

 

My 2 cents: You have a nice, quiet corner to work in here without every noob that wanders by offering sophomoric noobie suggestions. It looks like that strategy is working. Slow as you are, you aren't being cluttered up with kibitzing. My opinion is, stay with what works. The ship isn't sinking so you don't need to jump overboard.

#12 Thanks for feedback cuz it's vry reassuring to hear it from impartial source cuz what you're saying is basically HP's stance and JC just automatically agrees with everything HP says So tnx for independent objective affirmation!

 

tnx for independent objective affirmation

Count on it. I would tell you the truth (as far as I know what truth is) even if the truth was unpleasant.
But you already know that.

 

But sometimes I think ppl reading it on here could be confused abt why it's in off topic forum? So I'm saying that might cause doubt abt content like reading news story printed on Apr 1? Just sayin'

But then the only content they need 'take seriously' are the tutorial posts, etc... All of which will be posted to on-topic fora upon completion

Very best regards
HP

PS

and JC just automatically agrees with everything HP says

Hmmm... Perhaps as a test of your assertion I should ask him to place his gaming console atop his Tesla coil?...

Howz about it @Jazz2C?

 

I couldn't imagine why you could not see the difference between my style and yours and decipher these things because you clearly have the upper hand in language use.

Well indeed I am aware of said difference - howbeit I wouldn't characterize preference for formality as 'the upper hand'...

I hope it is clear that I hold no ill will toward you.

Style is not a character defect.

Thanks and ditto!

Hmmm...never heard of a "gray" as a unit of radiation.

The Gray is the SI unit of absorbed dose whereas the RAD is the CGS unit of absorbed dose.

Spec: 1 Gray represents absorption of 1 joule per kg whereas 1 RAD represents absorption of 1 erg per 10mg (hence 1 Gy = 100 RADs)

Note the similar relationship of SI vs. CGS units of equivalent dose (To wit the Sievert and the REM respectively)

FWIW I prefer the CGS units myself -- but then the demands of globalism grant quarter to neither convenience nor common sense

polyepoxide, Is that from Chemistry class?

It's merely the generic (i.e. 'chemical', if you will) name for the group of compounds in question...

Etiquette: more formal than "good manners".

Then too there is the subtle difference in definition... (to wit: 'Manners' references conduct itself whereas 'etiquette' references code of conduct)...

tradyness: not in Dictionary.com, Merriam-Webster British dictionary, or The Urban dictionary.
A reference to, "Trade names"?

---Emphasis Added---

Essentially correct... 'tradyness' refers to nomenclature via 'commercial spin' as opposed to accurate product/device/substance description --- Paraffin "wax" and Canned "air" being especially egregious (and, in the latter case, potentially dangerous) examples of said practice...

It is entirely possible I heard "aural" used correctly and assumed I heard "oral".

No worries! - It's a common mistake -- like as not such usage will become 'standard' in the fullness of time

"sans provision for admission": IMW, "admission" is what you pay for at the gate, or reluctantly do during a police interrogation. Admission of oil conjures a comical picture of a quart of oil paying for entry into the windings. Around here, oil penetrates, or saturates, but it doesn't ask to be admitted.

Come to that, 'intromission' is more precisely descriptive of the process of 'fluid permeation' than either 'admission' or 'penetration'. -- Sadly, the former's usurpation by vulgarians (inept though it was) has increased said verb's 'distraction factor' beyond practical limits -- That said, in light of the 'knuckle-draggers' ongoing 'hachet job' on 'penetration' - 'Admission' is looking like emerging as the last 'synonym' standing

"specification of mammography enhancers was vital..." I did not know that. I assumed all x-ray cassettes were built to utilize the least radiation congruent with efficacy.

The distinction between energy level and power/dose is vital! --- By way of example: A 1 mW blue LED is a source of higher energy light than a 1 GW green laser! --- As a (related) aside: All else being equal - Exposure to low energy (aka 'soft') X-rays tends to be more injurious than exposures to higher energies (owing, primarily, to greater absorption [and, hence dose per time unit] of the former)... ALARA (and it's ilk) is concerned solely with (ultimate) dose...

The difficulty I have in understanding you leaves few, if any, brain cells to try to divine your emotional content. In fact, I suspect the, "formal" tone intentionally obfuscates that aspect.

While I am uncertain as to the 'cause vs effect of it' -- I certainly agree that sentiment has no place whatever in formal communication (including all aspects of education) -- That said, formality is intended to enhance perspicuity - I apologize that my application of same has not met with unqualified success in that regard

Where do you get this kind of education??? I don't even know which classes I would enroll in to emulate you!

Seriously! -- It's merely a literary style -- nothing more -- formally (NPI) described as 'The Very Formal Tone' (q.v.) --- For all that, I tend to 'let myself down' a bit on the 'very'

Very best regards
HP

 

It's a common mistake -- like as not such usage will become 'standard' in the fullness of time

Your prediction comes true immediately.

Both wayneh and the U.S. army think the test is oral.
https://forum.allaboutcircuits.com/threads/picture-this.110947/page-26#post-1149277
post #520

 

Both wayneh and the U.S. army think the test is oral.

Away back in the daze (sic) of my youth someone told me that conscientious 'brushing and flossing' was with its advantages -- seems they were on to something!

TTFN
HP

 

@Aleph(0)

As a matter of courtesy to other readers (and, indeed, the advantage of multiply-sourced opinion/insight) please! Post all questions that you wish answered on these fora to these fora! -- There can be little less interesting than viewing what amounts to one side of an 'SMS' conversation!

But to continue:
Re: Ceramic caps: N4700 merely specifies a temperature coefficient (Specifically -4700 ppm [0.47%] per °C ) -- while the EMF coefficient is reasonably 'flat' (well... 'low') -- FWIW all EIA 'Class 1' dielectrics feature low dissipation, highly 'predictable' temperature coefficients and low EMF coefficients -- IOW it's all good!

Best regards
HP

 

As a matter of courtesy to other readers (and, indeed, the advantage of multiply-sourced opinion/insight) please! Post all questions that you wish answered on these fora to these fora! -- There can be little less interesting than viewing what amounts to one side of an 'SMS' conversation!

HP I know you don't like to hear abt it but it's just cuz I can't always login on here cuz of connection problems but since I want to discuss EHT related questions here I don't think I'm asking too much of you to just respond with reference to my question?

Re: Ceramic caps: N4700 merely specifies a temperature coefficient (Specifically -4700 ppm [0.47%] per °C )

HP At first I thought that was typo but now I get it cuz °K and °C are same size!

FWIW all EIA 'Class 1' dielectrics feature low dissipation, highly 'predictable' temperature coefficients and low EMF coefficients -- IOW it's all good!

HP I agree cuz some class 2 caps have just awful voltage coefficients like Y5U and Z5U are like -80% at full voltage which I say amts to to deceptive labeling when capacitance is specified at like basically 5% voltage rating! I remember how Lockeed Martin sued and won huge damage settlement from shady vendor for that and I say any vendor that specifies like 60kv cap at 50nf that's only 10nf at 60kv is guilty of fraud plain and simple! So now there's legal precedent that hiding behind deceptive backroom industry standards and fine print is not a successful defense! HP I know you just say _caveat emptor_ which is always good advice but that doesn't give sleazy marketeers the right to lie abt products!

So anyhow I'm happy 2 know those _door knobs_ are first rate!

 

HP I agree cuz some class 2 caps have just awful voltage coefficients like Y5U and Z5U are like -80% at full voltage which I say amts to to deceptive labeling when capacitance is specified at like basically 5% voltage rating!

Re: "voltage" coefficients - 100% agreed! -- A 50nF capacitor which being out of tolerance anywhere within its specified working EMF range is not a 50nF capacitor and should not be offered as such!

Ironically, among the alleged 'pros' of class 2 dielectrics is their "superior" (do note the quotation marks) volumetric efficiency - which being dubious in all cases and utter nonsense at EMFs much beyond 10% maximum (device) working EMF specification

The message industry doesn't seem to apprehend is the fact that we (i.e. consumers in general) are willing to pay for genuine quality - sans games, loopholes and outright lies!

Best regards
HP

 

HP I know you don't like to hear abt it but it's just cuz I can't always login on here cuz of connection problems but since I want to discuss EHT related questions here I don't think I'm asking too much of you to just respond with reference to my question?

While indeed it is not 'too much to ask' of me, I, nonetheless, feel such to be discourteous to our readers who have every right to expect 'visibility' of both sides of the conversation! @Aleph(0), at risk of 'whipping a dead horse' - I, once again, draw your attention to the fact that a solution to your 'connection difficulties' is readily available! -- I think I will never understand how it is that you imagine on-line socialization via a system containing 'sensitive' data through a VPN (secure though such may be) is somehow more secure than use of a dedicated system containing no confidential/proprietary data whatever albeit through a non-encrypted, non-anonymized ISP (as per my suggestion)? -- That said, I'm maintaining an open mind... For the nonce...

---But to continue---

Re: your PSU's power transformer saturation/noise 'woes':

First of all - I would have though it should be obvious that net-nonreactive loading of magnetic forward transformation topologies cannot result in saturation! (so long, that is, as the load does not impose a DC offset upon the winding{s} of said transformer)

Please be advised that -quite contrary to common misinformation- tapped secondary 'full-wave' rectification arrangements do indeed impose instantaneous DC 'offsets' upon each half of the secondary with corresponding instantaneous magnetic bias upon the entire core (please note that, Re: said arrangement, secondary current does not reverse polarity each side of the tap) -- While said operation is arguably 'less egregious' than that of 'half-wave' schemes (in that 'side-to-side alternation' of polarity tends to 'demagnetize' the core) the core is, nonetheless, 'DC biased' toward (or into) saturation during each half cycle...

All of which is to say -- 'Bridge' (rectification) topology is beautiful for the continuous nature of 'double-way lading'...

Assuming your difficulty does not owe to one or more of:
-insufficient excitation frequency (Not likely off 'utility' mains but worth a check)
-Excessive excitation harmonic content
-Excessive excitation EMF
-A dubious rectification arrangement (as discussed above)

My 'best guess' (based upon the info provided) is that your PSU's transformer is being 'nudged' into saturation via presence of a DC offset on your line owed to connection of a device employing a 'phase control' or 'rectifier dropping' scheme to your distribution transformer's secondary -- Please know that such devices are more common than you may think

Note: conscientious investigation of said possibility entails disconnecting (as opposed to merely 'switching off') suspect devices...

Best regards and good luck!
HP

PS -- @Aleph(0) - Please make a special effort to post your questions/comments to these fora! -- Inasmuch as a 'painless' solution to your (connection) difficulty exists, my patience in this regard is rapidly approaching its limit!

 

I, once again, draw your attention to the fact that a solution to your 'connection difficulties' is readily available! -- I think I will never understand how it is that you imagine on-line socialization via a system containing 'sensitive' data through a VPN (secure though such may be) is somehow more secure than use of a dedicated system containing no confidential/proprietary data whatever albeit through a non-encrypted, non-anonymized ISP (as per my suggestion)?

HP ONE MORE TIME!

HP when Steve did just like that he was accused of trying to pull a _Hilly_ so I'd be big hypocrite if I did it after being party to bringing him up on charges HP you think I have no boss but clients are boss is not just lip service! They're jumpy about security and I understand that!

So dedicated socialization computer isn't a problem but failing to use totally secure anonymous connection all the time every time on every server is totally out of the question! Cuz important info has a way of _creeping_ to where it doesn't belong in millions of little pieces where patient cyber snoops can piece it together given half a chance! That's why I dismissed SH w/o proof of intent but just on grounds total negligence that could have been disastrous! And it's why I won't be an idiotic hypocrite by doing same thing! So it's totally up to you if you want to make like _absentee posts_ for me when I can't access forums but plz stop blaming me for situation that's totally Leaseweb's fault!

First of all - I would have though it should be obvious that net-nonreactive loading of magnetic forward transformation topologies cannot result in saturation!

HP all I said was noise and heating increased with loading but I didn't mean to imply it was cause of saturation! So like a lot of ppl I admit to being weak on magnetics But I'm not that clueless!

contrary to common misinformation- tapped secondary 'full-wave' rectification arrangements do indeed impose instantaneous DC 'offsets' upon each half of the secondary with corresponding instantaneous magnetic bias upon the entire core (please note that, Re: said arrangement, secondary current does not reverse polarity each side of the tap) -- While said operation is arguably 'less egregious' than that of 'half-wave' schemes (in that 'side-to-side alternation' of polarity tends to 'demagnetize' the core) the core is, nonetheless, 'DC biased' toward (or into) saturation during each half cycle...

HP Ok! Now I get it cuz of diodes current can only flow one direction on one half of winding and only in opposite direction on other half so split secondary rectifier is just as ugly as it looks which is just two half wave rectifiers taking turns HP I never did like that circuit just on aesthetics now I see its brand of ugly is more than skin deep
So anyhow my setup uses bridge so that's not problem but thanks anyhow cuz of giving form to my suspicions of tapped circuit!

Please be advised that -quite contrary to common misinformation-

HP that's something that's bothering me more and more! As much as I hate it, I can understand stupidity, ignorance and even laziness as inevitable part of human experience in all areas! But it's troubling to see intelligent educated ambitious ppl just copying and citing misinformation w/o even giving it a moment's thought all on grounds of it being from supposedly _reliable source_! HP I know it sounds like whining but it's totally disillusioning me with science cuz that sort of BS doesn't happen in abstract studies (like pure math)! Also ppl are grateful but not even embarrassed when they're corrected which means they're just shamelessly outsourcing like _alpha testing_ to their students and readers which is just wrong! HP I like physical science cuz it can be like _hands on math_ but a lot of ppl calling themselves scientists aren't keeping the faith which I say is death knell for future of real science which is already being totally fragmented by layers upon layers of _microscopic specialization_ so nobody can or even wants to see _big picture_ anymore! Science is drifting away from intellectual pursuit to just another piecemeal trade and nobody seems to care!

My 'best guess' (based upon the info provided) is that your PSU's transformer is being 'nudged' into saturation via presence of a DC offset on your line owed to connection of a device employing a 'phase control' or 'rectifier dropping' scheme to your distribution transformer's secondary -- Please know that such devices are more common than you may think

Note: conscientious investigation of said possibility entails disconnecting (as opposed to merely 'switching off') suspect devices...

HP Ok I looked at line with MDO and there's DC offset of abt 140mv! So I'll do some investigating and let you know what I find

HP Just so you know I have question abt modification of line frequency toroidal isolation xfmr but I'll save it until I solve this problem TNX!

 

HP Ok I looked at line with MDO and there's DC offset of abt 140mv! So I'll do some investigating and let you know what I find

Hey @Aleph(0) -- This is to advise you that I plan to post a comprehensive reply following your pending update

Best regards
HP

 

HP Ok I looked at line with MDO and there's DC offset of abt 140mv! So I'll do some investigating and let you know what I find

What's an MDO, and how did you use to measure DC offset on the line?

 

Hello,

HP has a lot of abbreviations in her blog, but the MDO is not in it:

Expansions of select abbreviations
Published by Hypatia's Protege in the blog Hypatia's Protege's blog. Views: 451

Expansions of certain abbreviations used in the EHT Power Supply tutorial series
⇒AWG: American Wire Gauge
⇒CAS: Chemical Abstracts Service
⇒CCM: Continuous Conduction Mode
⇒CPVC: Chlorinated Polyvinyl Chloride
⇒CRT: Cathode Ray Tube
⇒DST: Diode Split Transformer
⇒EHT: Extremely (or Extra) High Tension – For these purposes descriptive of EMFs ≥ 50kV
⇒EMP: Electromagnetic Pulse -- Synonymous with TED
⇒FA: Fixed Anode
⇒eV: Electron Volt{s}
⇒FCC: Federal Communications Commission (USA) -OR- Food Chemical Codex dependent upon context
⇒GMT / G-M Tube: Geiger–Müller Tube
⇒Gy Gray
⇒hFE: [Hybrid] Forward Transadmittance
⇒LOPT: Line Output Transformer
⇒MOT: Microwave Oven power Transformer
⇒NST: Neon Sign Transformer
⇒OBIT: Oil Burner Ignition Transformer
⇒OID: Object to Image receptor Distance
⇒OTC: Over The Counter
⇒PBB: Polybrominated biphenyl
⇒PCB: Polychlorinated biphenyl -OR- Printed Circuit Board dependent upon context
⇒PCMC: Peak Current Mode Control
⇒PMT: Photo Multiplier Tube
⇒PTFE: Polytetrafluoroethylene (Commonly, howbeit non-exclusively, marketed under the trademark: ‘Teflon’)
⇒PVC: Polyvinyl Chloride
⇒PVDF: Polyvinylidene Difluoride (Commonly, howbeit non-exclusively marketed under the trademark: ‘Kynar’)
⇒RA: Rotating Anode
⇒RAD: Radiation Absorbed Dose
⇒REM: Roentgen Equivalent Man
⇒RTV: Room Temperature Vulcanizing silicone adhesive compound
⇒SID: Source to Image receptor Distance
⇒SOD: Source to Object Distance
⇒Sv: Sievert
⇒TC: Tesla Coil
⇒TED: Transient Electromagnetic Disturbance -- Synonymous with EMP
⇒USP: United States Pharmacopeia
⇒ZCS: Zero Current Switching
⇒ZVS: Zero 'Voltage' Switching
To be amended/expanded as required...

XFMR: Transformer (Electromagnetic)
IC: Ionization Chamber
FB: Synonymous with LOPT (qv.)
FBT: Synonymous with LOPT (qv.)
SD or SDX = Shell Diala

MDO seems to be a method of optimization:
http://encyclopedia.thefreedictionary.com/Multidisciplinary+Design+Optimization

Bertus

 

What's an MDO, and how did you use to measure DC offset on the line?

Based upon context, I can but assume @Aleph(0)'s reference is to a 'mixed domain oscilloscope'... -- I'll alert Aleph to your inquires - many thanks for your interest!

Hello,

HP has a lot of abbreviations in her blog, but the MDO is not in it:

I'll be happy to include expansions of abbreviations descriptive of basic test equipment (in the browsable and linkable glossaries) if it is felt such would be helpful? -- Although our principal focus is upon EHT generation/phenomena and (certain aspects of) particle physics - I'd be delighted to think these resources might serve as a 'primer' on (or, at least, an introduction to) related subjects!

Re: The Glossaries -- While, at this time, said references are merely 'expansion lists' - You (i.e. all interested parties) have my word that they will attain to the dignity of glossaries in the fullness of time!

FWIW -- We really are planning resumed development of the tutorial series in the near future! - For all that, I hesitate to specify timelines inasmuch as (off-line) 'life' has tended to belie my optimism in said regard

Many sincere thanks to both of you for your interest and feedback!

Best regards
HP

 

Based upon context, I can but assume @Aleph(0)'s reference is to a 'mixed domain oscilloscope'... -- I'll alert Aleph to your inquires - many thanks for your interest!

I'm interested in the details of how she made the measurement with an oscilloscope given the oft repeated cautions about using scopes to make measurements on the line:

https://forum.allaboutcircuits.com/threads/scope-on-floating-ground.94489/

https://forum.allaboutcircuits.com/...loscope-versus-isolating-test-circuit.122795/

 

Hello,

I never heard about a MDO, so I did a little search and found this interesting info about it:
https://www.rs-online.com/designspark/the-mixed-domain-oscilloscope-:-how-it-works

Bertus

 

I'm interested in the details of how she made the measurement with an oscilloscope given the oft repeated cautions about using scopes to make measurements on the line:

https://forum.allaboutcircuits.com/threads/scope-on-floating-ground.94489/

https://forum.allaboutcircuits.com/...loscope-versus-isolating-test-circuit.122795/

As a matter of courtesy (and owing to my ignorance as regards the specifics of her test procedure) I'll let @Aleph(0) speak for herself (AFAIK she's planing participation here this coming weekend) -- For my part I apologize was any portion of our discussion in violation of this site's bylaws! -- Please be advised that we take safety very seriously at personal levels and especially in our official and unofficial 'consultancy' roles - including all advice and suggestions offered on these fora (manifest and tacit)...

I hope it is understood that I and I alone own any culpability in this matter inasmuch as it was I who urged @Aleph(0)'s public discussion of her various electronics-related issues/questions...

Sincerely - thanks for your concern!
HP

 

the oft repeated cautions about using scopes to make measurements on the line:

The Oft Repeated Cautions are for beginners who don't understand why they need an isolation transformer, not seasoned pros working with more than 50Kv and using Mixed Domain Oscilloscopes that can cost as much as $20,000. The reality of it is probably much simpler than you might imagine because I can't think of any 'scope which is prepared to survive 50Kv, even if it's battery powered. I expect an external voltage divider like the 50Kv probes used for television CRT anodes, but I eagerly await a response from Aleph.

(These two ladies have taught me how much I don't know as much as anybody else on this site.)

https://www.ebay.com/sch/i.html?_nkw=tektronix+mdo