Do you build or just for learning.
because manufacturing is not easy task

We design and construct EHT systems for research and 'leisure' -- Definitely not for business purposes!

Best regards
HP

 

W

e design and construct EHT systems for research and 'leisure'

Ok, was this is your job role?
because i am not getting how it work and use of it.

 

W
Ok, was this is your job role?
because i am not getting how it work and use of it.

This has nothing to do with my occupation -- It's merely a pastime -- a hobby, if you will

This thread (where on topic) concerns design and construction of EHT power supplies with special emphasis upon application to radiography and radiotherapy systems...

If you're interested, please see post #247 -- be warned, however, that it is a work-in-progress and, hence, rather 'heavy going' at this time

Best regards, and again, many thanks for your interest!
HP

 

because i am not getting how it work and use of it.

Assuming you are referring to the circuit illustrated in post #278

When the SCR (Thyristor) is 'on' the bridge conducts between the load and ground nodes despite polarity -- such an arrangement is useful inasmuch as high power Triacs having desirable characteristics are difficult to manufacture via present technology...

Best regards
HP

 

HP thanks is perfect! I tested it to 5 min on 50kw and HS gets barely warm! I setup trigger circuit so it is pic controlled with digitally scaled feedback loop. Now so much better than old motor driven variac connection! HP I didn't like way xfmr sings cuz of harmonics so I now using 2 pole lpf for primary. Now its audibly quiet and has very nice waveshape but I am asking is that enough to totally protect xfmr? HP I have rebuilt 2 fbs by following tutorial so looking forward to experiment with drivers

 

I didn't like way xfmr sings

Thus it seems you prefer a baritone to a five octave soprano???

...cuz of harmonics so I now using 2 pole lpf for primary.

Whatever works - but you're 'tossing' a lot of energy... -- IMHO said harmonics will not degrade the winding insulation - FYI most of the perceived sound owes to magnetostrictive vibration of the core - not the windings --- As a practical matter, owing to increased core losses, the transformer may heat more than would be the case with sinusoidal excitation - though such would seem of little significance considering the highly intermittent duty of the application... That said, 'heavy' transient suppression (via 'gas fuses' not MOVs) is advisable...

HP I have rebuilt 2 fbs by following tutorial...

Great! -- I'm pleased the tutorial is useful even in its present sorry state of [dis]order'

looking forward to experiment with drivers...

I'm working on it!!! -- Patience! - Once the current (i.e. LOPT Preparation) tutorial is completed and moved to 'Projects' I'll start in earnest on a discussion of exciters/drivers!
Truth be told, as regards the current tutorial, I seem to have 'lost my stride' -- Seems no matter how I word and reword the intro the result errs distinctly on the side of somnolence -- Ergo the inadvisability of hiatuses 'in midstream', as it were!

Well hey!!! --- Please rest assured that I'm as eager as you to continue! -- 'Tis merely a matter of overcoming this crippling inertia!

All the best
HP

 

@Aleph(0)

Please see this post

Very Best Regards
HP

 

Following is an incomplete list of (expanded) abbreviations used on this thread. Please note that said list is restricted to abbreviations having scant or 'spotty' representation in current EE/ETech 'vernacular'...
This is a work in progress -- Suggestions welcome!

--Unsorted at this time--

EHT = Extremely High Tension (Generally applicable to EMFs >20kV)
HV = High Voltage (synonymous with EHT in this context)
LOPT = Line OutPut Transformer
FB or FBT = FlyBack Transformer (synonymous with LOPT in this context -- although more generally descriptive of a topology as opposed to a specific application)
Xfmr = (electromagnetic) Transformer
PE = Photon Energy
RA = Rotating Anode (Coolidge tube)
FA = Fixed (i.e. stationary) Anode (Coolidge tube)
DRT = Deep Radio Therapy
CT/CAT = Computed Tomography/Computed Axial Tomography
TC = Tesla Coil
CWC/CWM/CWVM = Cockcroft-Walton Cascade/Cockcroft-Walton Multiplier/Cockcroft-Walton Voltage Multiplier
VDG=Van De Graaff Generator
MAS = MilliAmpere Seconds (i.e. jargon for millicoulombs {mC})
SD or SDX = Shell Diala (A brand of dielectric 'potting' oil)
PCB = PolyChlorinated Biphenyl (Descriptive of a dielectric oil 'chemistry')
RAD = Radiation Absorbed Dose (Eqv. to 0.01 Gray {Gy})
REM = Roentgen Equivalent Man (Eqv, to 0.01 Sievert {Sv})
IC = Ionization Chamber
GM = Geiger Muller (generally prefixes 'tube', 'counter', 'detector', etc...)
kVp = Peak EMF (denominated in kV) applied to a radiography/radiotherapy tube.
keV = Thousands of electron volts (a unit/denomination of photon energy and, hence, for these purposes, descriptive of electromagnetic 'spectra').
Gy = Gray (The SI unit of absorbed [ionizing radiation] dose)
Sv = Sievert (The SI unit of ionizing radiation dose equivalent)

/////

Although the following will be familiar to electronics professionals/enthusiasts such has been included as a courtesy to 'beginners':

BJT=Bipolar Junction Transistor
FET=Field Effect Transistor
HPF=High Pass Filter
LPF=Low Pass Filter
MOSFET=Metal Oxide Semiconductor Filed Effect Transistor
PIC = Programmable/Peripheral Interface Controller (loosely microcontrollers in general) --Alternately-- Picture (i.e. photographic image or drawing)
RF=Radio Frequency (Descriptive of AC or electromagnetic radiation at frequencies greater than approximately 20kHz)
SOE = Stripline Opposed Emitter package (As applied to BJTs)
SOS = Stripline Opposed Source package (As applied to MOSFETs) --Alternately-- Silicon On Sapphire (semiconductor technology)
uC = Microcontroller
CRO = Cathode Ray Oscilloscope
DPO= Digital Phosphor Oscilloscope
DSO = Digital Storage Oscilloscope
TDO = Time Domain Osciloscope
SA = Spectrum Analyzer (i.e. Frequency Domain Oscilloscope)

 

Try again! -- Wrong party - wrong Government

I say all parties in all governments are same! CONTROL PARTY!

 

Thus it seems you prefer a baritone to a five octave soprano???

IMHO said harmonics will not degrade the winding insulation

HP reason I worry is that if motor not inverter duty vfd can damage windings so I worry if same for transformer with non sine drive?

That said, 'heavy' transient suppression (via 'gas fuses' not MOVs) is advisable...

HP why not MOV?

I'm pleased the tutorial is useful even in its present sorry state of [dis]order'

HP you too modest! I say your super detailed descriptions are lovely!

I word and reword the intro the result errs distinctly on the side of somnolence

HP you shouldn't be worrying about that! Anyone bored either already knows material or doesn't care anyhow!
Now I am saying that there are exceptions but ppl easily bored are usually too dim to think about cuz like you say curiosity and intellect are like handmaidens!

 

HP reason I worry is that if motor not inverter duty vfd can damage windings so I worry if same for transformer with non sine drive?

The principal additional stresses encountered in VFD operation of induction motors are: 1) Excessive run temps secondary to ineffective integral cooling fan performance at lower AVs --- and 2) Over-EMF conditions owed to 'transmission line effects' apparent upon the power leads... Clearly the former is inapplicable to transformer operation whereas the latter is mitigated via use of OVPs and maintenance of minimal control to transformer lead length...

HP why not MOV?

In my experience 'gas fuse' style OVPs are both faster and longer lived... --- That said I've seen many 3θ controllers incorporating 'hefty' varistor OVPs (in industrial equipment auction lots) --- Point being, as a practical matter, it may be no more than personal preference on my part --- Note, however, that where such MOVs are used - they are large -- bearing no resemblance to the familiar consumer/light industry grade 'discs'...

HP you too modest! I say your super detailed descriptions are lovely!

While I sincerely appreciate your kind words -- I'm bound to say, as previously discussed, that the interdisciplinary 'mish mash' seems likely to be off-putting to some readers

Anyone bored either already knows material or doesn't care anyhow!

The function of an introduction is to 'reach' the intended readers - many of whom will, understandably, be 'turned off' by a verbose, pedantic prologue! -- It's hardly the reader's fault if they loose interest prior to reaching the content!

ppl easily bored are usually too dim to think about cuz like you say curiosity and intellect are like handmaidens!

Agreed as far as it goes howbeit I suggest that such is not 'transitive':

To wit:
I agree with the assertion that, as a rule, stupid people bore easily ---However--- Being easily bored is hardly diagnostic of stupidity! --- À la all ducks are birds --however-- not all birds are ducks!

In any event, I strongly doubt that the message: "If you don't like our tutorial it means you're stupid!" is going to 'score' us any readers!!!

All the best
HP

PS For the benefit of interested parties --- Here's an expansion of possibly ambiguous abbreviations used in this discussion:
VFD=Variable Frequency Drive
OVP = Over 'Voltage' Protector
AV = Angular Velocity

 

Attn: @Aleph(0)

Please see your ISP provided email ASAP -- It's all good!

 

Note, however, that where such MOVs are used - they are large -- bearing no resemblance to the familiar consumer/light industry grade 'discs'...

HP Plz upload pics so I can spot them in junked out equipment from GS auction

In any event, I strongly doubt that the message: "If you don't like our tutorial it means you're stupid!" is going to 'score' us any readers!!!

HP I didn't say that! I'm only saying you shouldn't insult the smart people by catering to dummies!

Please see your ISP provided email ASAP

Done and done!

 

HP Plz tell me what is the surge energy rating on big movs?

 

Hey @Aleph(0) ! --- I'm not ignoring you!!! --- 'Tis been quite a week

HP Plz tell me what is the surge energy rating on big movs?

HP Plz upload pics so I can spot them in junked out equipment from GS auction

If I can get the loader started I'll try to dig a few out

All the best
HP

 

Hey @Aleph(0)If I can get the loader started I'll try to dig a few out

HP no need to make a major production out of it! I only want to see pic so I can id them without buying the whole f''ing lot from AJ! Otherwise I'll survive HP I thought you retrofitted lift trucks for running on H2? I say fuel that volatile will start it right up! HP Plz say when you can start tutorial about fb drivers? I'm like over reved and no load!

 

HP no need to make a major production out of it! I only want to see pic so I can id them without buying the whole f''ing lot from AJ! Otherwise I'll survive

What's with the 'tude?

HP I thought you retrofitted lift trucks for running on H2? I say fuel that volatile will start it right up

Not hydrogen, LP gas... Moreover fuel volatility/ambient temperature isn't the problem -- turns out rodents loaded the 'filter chamber' with what looks to be bird seed -- So I'll have to use shed #4's loader pending repairs...

It's no 'big deal', I've been meaning to check on some other items anyway...

HP Plz say when you can start tutorial about fb drivers?

As soon as I complete (i.e. compose a decent introduction for) the current tutorial!!! -- If you're in a hurry, you're more than welcome to finish it!!!

I'm like over reved and no load!

Guess we're gonna have to find you a gov-na

All the best
HP

 

HP Don't be worrying if you can't get movs by tonight. I can get them from Ann and Tony anyway so plenty of time to take pics so I know what I'm getting. Cu in a few hours!

 

Just an update to (any?) 'followers' of this thread:

The recent inactivity owes to the fact that Aleph is currently my guest - she is without (practical) access to her 'usual' ISP and I have asked her to refrain from posting through my ISP (for obvious reasons).

Anyway, I expect to complete the current tutorial and get on to a similar (if less 'halting') treatment of LOPT drivers within the next few weeks (following Aleph's return to the fora)!

Many thanks for your patience!
HP

 

Anyway, I expect to complete the current tutorial and get on to a similar (if less 'halting') treatment of LOPT drivers within the next few weeks (following Aleph's return to the fora)!

I'll believe it when I see it