Talk:Marx generator

message: http://home.earthlink.net/~jimlux/hv/marx.htm mentions the effect of UV radiation from the initial triggering on the subsequent spark gaps.  Would it be possible to construct a marx generator in which the first spark gap is triggered using a UV source such as UV L.E.D's to ionize the air in the spark gap? --Pypex 22:49, 28 August 2005 (UTC)
replies: text: The first gap is often a triggerable spark gap such as a trigatron, or self-triggered by spacing (or mechanically moving) the first gap electrodes closer together than all of the remaining gaps. The first gap can also be triggered by something that injects a significant number of free electrons into the gap to stimulate avalanche breakdown. This can include a radioactive material in the electrode(s) or as a gas dopant, or an external energy source such as X-radiation, an electron beam, or a short wave UV laser. If the UV LED had a short enough wavelength to ionize oxygen molecules in the air gap (less than ~200 nm), then it could work as a triggering source. However, currently available commercial UV LED's only go down to about 350 nm, so it looks like they wouldn't work. Bert 02:50, 31 March 2006 (UTC)
thread_title: UV Triggering?

message: In many practical implementations, the charging source is not a constant voltage source, but, rather, something with more of a constant current type characteristic. (e.g. a voltage multiplier stack). This reduces the energy dissipated in the charging resistors, which otherwise, would be equal to the energy stored in the capacitors.  It might also change the dynamics of the charging.
Jim Lux
137.79.6.96 19:51, 15 February 2007 (UTC)
thread_title:  Non constant voltage charging 

message: The long list of patents adds very little to this article. Do we need it? — BillC  talk 09:59, 23 February 2008 (UTC)
thread_title:  Patents 

message: I recently read a few research papers that discussed various methods of replacing the spark gaps in a Marx Generator with Insulated-Gate Bipolar Transistors (some of them are here: ). Is this significant enough to mention in the article? Ilikefood (talk) 18:39, 26 August 2008 (UTC)
replies: text: Yes, that's a good idea. If you're lucky, your library might have some of those journals available on-line, especially if you have a university account. It's worth a call to your librarian - I just found ours has a bunch of IEEE publications available, just not the Plasma Science one mentioned in your links. --Duk 19:57, 26 August 2008 (UTC)
replies: text: When I had access to them, I read several. It appears that one of the research groups (the one with the IGBT stack, not the single IGBT per stage) also used their IGBT stack to drive a pulse transformer in a separate research paper, and wrote two papers about their marx generator. There were several ingenious methods of decreasing charge times, such as using diodes to isolate the stages. I can't remember how exactly they connected them, but it was pretty cool. Ilikefood (talk) 18:03, 28 August 2008 (UTC)
thread_title:  Should we mention IGBT switching? 

message: Where is it mentioned it needs a high voltage power supply like a Cockcroft-Walton generator?  —Preceding unsigned comment added by Ericg33 (talk • contribs) 07:07, 9 January 2009 (UTC)
thread_title:  powersupply? 

message: I've got to comment that the coaxial Marx diagram on this page is not very clear at all.  I suggest cleaning it up and using standard schematic symbols for the components so you can tell what's going on.
--23.16.194.76 (talk) 22:22, 19 February 2019 (UTC)
thread_title:  Coaxial Marx diagram 

message: How do you calculate suitable values for the charging resistors or inductors ? and is it useful to have the first top left resistor with a higher value (relative to the others) (eg to speed up charging the rightmost capacitors) ? eg. Would it be OK say to have the resistances some small multiple of the highest likely load resistance (so only a small proportion of the energy is dissipated in the charging resistors ) ? - Rod57 (talk) 12:05, 19 March 2017 (UTC)
thread_title: How do we size the charging resistors/inductors

message: In Principles of operation it says "...the output is a brief pulse as the capacitors discharge through the load (and charging resistors)." which seems contradicted by the discharge diagram which shows discharge only via the spark gaps. Suggest change "(and charging resistors)." to something like "(and higher impedance charging resistors to a smaller extent)." ? - Rod57 (talk) 00:25, 29 March 2017 (UTC)
thread_title:  Confusing wording 

message: In the article it says "none of the charging resistors Rc are subjected to more than the charging voltage even when the capacitors have been erected[clarification needed]." In a comment on this talk page it says "... propose the term "self-break" for the first switch to initiate erection of the Marx generator." so maybe "erection" means "discharge", or more likely "recharge". 
I'll change "erected" to "fully charged". - Rod57 (talk) 11:32, 19 March 2017 (UTC)
replies: text: Agreed. "Erected" makes no sense at all. Andy Dingley (talk) 23:24, 28 March 2017 (UTC)
replies: text:  @glrx  Hi I see you reverted my change saying "erected is meant; capacitors never see SHV when triggered)" - I'm a native speaker of english and dont understand what erected can mean in this context. Could you please explain or paraphrase - perhaps here on the talk page if you wish. thanks. - Rod57 (talk) 00:11, 29 March 2017 (UTC)
replies: text:  It has nothing to do with charging the capacitors; during charging the capacitors and resistors never see more than the charging voltage; that should have been a clue. Super high voltages are only seen (and only an issue) when the capacitors are erected (stacked). It's a common term. See wikt:erect (verb). See wikt:erection. A kid's toy is an Erector Set. Consider the erection of Washington Monument: a very high voltage (obelisk) is made by stacking a bunch of little voltages (stones) on top of each other. Cranes are used to erect a building. Generally, if you don't understand a phrase, you should not change it to something different. If you had googled "marx generator erection", you should have come across items such as "Development of a 2.4 ns rise time, 300 kV, ∼ 500 MW compact co-axial Marx generator" and "Noise reduction of Marx generator erection". Glrx (talk) 00:57, 29 March 2017 (UTC)
replies: text: I agree with Glrx.  The jargon "erect" (in spite of the funny associations) is widely used , , , , , ,   in describing the operation of Marx generators and should be in the article.  However the article should probably not just use it, but explain what it means.  As Glrx said, it describes what happens in the moment when the generator discharges; it "erects".  It's based on the analogy commonly used in electronics between potential (voltage) and physical height.  When the sparks jump across the spark gaps, the capacitors, which were previously being charged in parallel, are suddenly connected in series.  So the output end of the capacitor stack, which was previously at a low voltage (V_c) with respect to ground, suddenly "erects" to a higher voltage (NV_c).  It is as if the capacitors were previously lying on the ground and were stacked on top of one another to reach a high potential. --ChetvornoTALK 21:13, 17 May 2018 (UTC)
replies: text:  Yes, the word should be used. Erection was described but not named earlier in the paragraph. Glrx (talk) 00:11, 18 May 2018 (UTC)
replies: text: Ah, yes. I see. --ChetvornoTALK 02:17, 18 May 2018 (UTC)
thread_title:  erected/erection - seems a wrong translation