Jerry I've been doing some research on Ignitron commutation. Most of the articles are behind a pay wall, including the one about a twin tube MW inverter ($35), but some information can be gleaned from the abstracts. It seems that all Ignitrons can be commutated, not just the 7171 model used by Gray. One abstract states that the voltage transient produced when one tube is turned on switches the other one off. Another abstract indicates that any thing more negative than -.5V will work. Still another abstract mentions that Ignition commutation is the same as commutating an SCR. That's a really simple circuit and I'll dig it out when I have time. Unless some other member will help by posting it. Working from first principals I always found this kind of conversation strange. I built countless high voltage high current circuit elements like this and there's really nothing to them. I used mercury, molten lead, high conductance water/fluids and even metal filings/powder. In fact the coherer is similar and it can conduct at HV then break the circuit on vaporization, quenching or commutation/chopping. An ignitron simply introduces a HV effect as periodic mercury vaporization which is the only reason the conductance increases through the device. I say strange because many go on and on about the characteristics of a circuit element or device but never go into what it actually does, what is it?. Of course, this is the main defect of lump sum modelling/reasoning and people are taught not to question what something is or how it works in reality. It's like trying to understand a car by looking at it versus designing, building and driving one. Here it helps to understand many of these inventors, like myself, tend to fabricate most things from scratch. So where some see a simple lumped sum capacitor I used plate capacitors with variable conductance/corona effects which could handle over voltage/arc overs like a spark gap. Since we have corona we also have the possibility of plasma wave, physical effects and other variables within the element. Simply put, it's not the same thing and to suppose they are is a mistake. Lumped sum modelling may work for armatures but not serious FE researchers. I have found this is why 99% of people fail and never see anything in the way of an anomaly. By using lumped sum modelling, electronics and off the shelf components they have in effect done everything in there power to ensure they fail. They all do exactly the same thing ensuring they all get exactly the same results. AC
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Comprehend and Copy Nature... Viktor Schauberger
“The first principle is that you must not fool yourself and you are the easiest person to fool.”― Richard P. Feynman
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