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3:19 AM
@adamaero I wasn't asking it in that way. I want to know the chemistry and the advanced physics behind it. So I can make my own and to my own specs. Now going blind and thinking all diodes are the same is a death wish.
@adamaero Sure there's a semiconductor inside of it. But which one? How is it organized? What is the structure? What are the domains and are they also aligned? How does the charge effect the atomic structure of the domains? How do they interact and why? Do they interact with other atomic structures? There's a lot of things that go on with that.
@adamaero Just asking what makes a diode is a very very broad question. Compared to the questions I have.
I'm sure everyone here understands how a diode works and they all also understand why it works. But they might have to look up exactly what makes what work. My questions are deeper than that. The what? How? And why? questions scratch the surface.
@JRE I just got done making my mini power line set up for HV experiments up to 708 kV.
I still have some voltage buffers to put on it to minimize particle discharge.
The red 600 VAC wires on the sides hanging from the poles are ground potential wires. This is used to trip the GFCI. And with my testing at 10,000 volts AC it works. No resistor in line and not one needed. The red wires can either be attached to the green grounding wire. Or can be put on the ground or in the ground. It still works.
The GFCI only trips when the positive end of the AC output touches the ground or makes a connection to the ground. The negative AC wire does nothing as it is at ground potential already. The positive AC wire has a greater potential and takes electrons away from the negative or neutral ground potential.
Just a little HV knowledge. It'll always keep you safe if you understand how HV behaves and know what it will do and when.
Lots of people say to not ground the HV transformers to the house wiring ground. But the voltage released to the grounding circuit was meant to take HV. If you take a look at a Microwave circuit diagram it is always grounded to earth ground via the home electrical system.
@JRE I'll take a look at those links you sent.
@JRE Alibaba has a solid state 100 kV diode for 34-378. And I'm thinking of going the solid state route. I like solid state anything better. Because they are able to handle variations easier.
@JRE Ya know if I do end up making this. I'll make a YouTube video about it and then (if you want) I'll give the support and help credit to those who help me. For right now that would be just you.
Mouser seems to be more expensive. But it seems they both have good reputations. So I'll be a little more adventurous.
@JRE & @VoltageSpike I'm needing something that has the best insulation. For the kV per mm. I need something that isn't a gas. Like plastic. What is the best insulator that isn't a gas? I've ran into plexiglass having a particle discharge voltage be around 4 kV per mm. So that would be a Voltage breakdown of approximately 4.1 minimum or 4.2 maximum per mm. It could be more but I'm staying on the safe side.
 
 
2 hours later…
JRE
5:53 AM
Note that it goes into some detail about corona discharge. At 700kV with those skinny wires, corona discharge will be a real problem.
You should also take a look into the separation between wires. In normal conditions, the breakdown voltage of air is 3kV per millimeter. For 700kV, you need at least 23 cm separation. More, though, because if a speck of dust drift through there, it will precipitate an arc.
Also, that 3kV per millimeter assumes rounded objects. You wire diameter is too small. It'll look like a "sharp point" so the breakdown will occur at a lower voltage.
 
 
5 hours later…
JRE
10:56 AM
@ScientistSmithYT You'll be hard put to find anything that is not solid state these days. Tubes, yeah. Don't know if anyone ever made tube diodes rated for tens of thousands of volts - or if there are any still available.
Even cuprous oxide and selenium would count as "solid state," I think. They are solid, at least.
@ScientistSmithYT "Particle discharge" is a term you seem to have come up with on your own. You toss it around like every one should know it, but you haven't defined it. From the way you use it, I greatly suspect it is just corona discharge in some particular situation that makes you think it isn't corona discharge.
 
 
1 hour later…
12:13 PM
Hello people! Anybody there :-)
I have a question on transformers.
 
12:58 PM
@user8718165 . . ask away. Folks drop in here all the time.
 
@Marla Nobody responded so I thought it'd be a bad idea to ask...
Asking now :-)
 
Ok, then don't ask :/
 
@adamaero Ah...well...did I say something enraging?
 
No
Less traffic than Stack Overflow chats. More traffic than philosophy, psych, money, etc
 
@Marla In an ideal transformer, under no load condition, if we connect an AC supply of rated frequency...I've seen that 0 current will flow...why is that the case?
 
1:09 PM
@user8718165 . . not true. When the secondary is open, all you have is an iron core inductor. Which does draw current.
I guess it depends upon the definition of ideal
 
@Marla yeah so now that I have a simple inductor the current will slowly rise in the coil due to Lenz law...Is that the case?
 
That is one way to say it. Or, V = L * di/dt
 
1:28 PM
@Marla oh yeah :-) I remember...Can I just neglect the the secondary coil in an ideal case since it isn't carrying any current at all. I hope that's what you meant when you said
> When the secondary is open, all you have is an iron core inductor. Which does draw current.
 
Yes true. However, if you wanted an absolutely ideal transformer , as your original question was, you might not even want primary current into the primary inductance.
Secondary impedance is infinite, therefore the reflected impedance to the primary is infinite.
 
@Marla Okay... would you mind explaining "reflected impedance to the primary" once?
 
Primary impedance (ignoring primary inductance for the moment) = load impedance times the turns ratio squared.
Reflected was probably a poor choice of word for this discussion.
 
@Marla okay...get it
@Marla No worries :-) Thanks for you help and time
 
Very welcome
 
 
2 hours later…
3:37 PM
@ScientistSmithYT,
> Sure there's a semiconductor inside of it. But which one?
In low voltage applications, silicon. JRE already gave you an idea about this for high voltage.
> How is it organized?
As shown in the diagram posted by JRE.
With some variation depending on manufacturing technology.
> What is the structure?

As shown in the diagram posted by JRE
> What are the domains and are they also aligned?

The semiconductor will be a single crystal. No domains. (Maybe in high voltage there's a way to do it with polycrystalline material)
> How does the charge effect the atomic structure of the domains?

Charge shouldn't be changing atomic structures.
> Do they interact with other atomic structures?

Not sure what you mean here. If you throw a big enough atomic structure of rock at a thin enough atomic structure of glass, you've just thrown a rock through a window.
2
Obviously if you want to build your own diodes you need to get into a lot more detail than that.
But there's a reason semiconductor processing equipment costs millions of dollars.
Companies don't pay that just to look cool.
If they could make their products with $10k worth of equipment instead of $10M, they would.
Also, there's a lot of nasty chemicals that go into semiconductor processing. Arsene. Hydrogen cyanide.
Large chunks of Silicon Valley around the semiconductor factories of the 1960's thru 80's are Superfund sites.
You probably don't want that for your garage.
 
4:04 PM
Umm did my message get deleted
 
5:03 PM
@ScientistSmithYT Teflon has the highest resistance of any solid substance, I'm not sure what the breakdown is. Ceramics are also good for dielectric breakdown
 
5:13 PM
Folks, do the OLED displays (or OLED display controllers) allow to control the brightness of individual characters (or individual lines) ?
 
@NickAlexeev I would think that the character displays would not, a full blown display could do anything
 
@VoltageSpike I'm noticing that OLED displays often use LCD display controllers. Character LCDs can't be dimmed character-by-character, or line-by-line, as a rule.
There are 7-segment LED controllers which allow character-by-character dimming, by the way.
 
 
2 hours later…
7:07 PM
US gov't program from the 80s
 

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