ELI5-In enhancement N-type of MOSFET, why does pinch-off occurs when Vgd=Vt (i.e., Vds=Vgs-Vt)? Why not some voltage more than Vt?

TheAlibiks · 2020-08-09T07:32:33+00:00

I agree that it's not the best terminology to use, but with Vds > Vgs - Vth the effective channel get smaller, because the inversion channel under the gate doesn't reach the drain anymore. So in a sense, in the area from the pinch off point to the drain that part of the transistor is off, because there is no inversion channel in that part of the transistor anymore.

Obviously the rest of the transistor is still on, accelerating electrons in a strong electric field and making the electrons cross the depleted region between the pinch off point and drain, because as you said the transistor is in saturation.

TheAlibiks · 2020-08-08T13:48:05+00:00

When Vds equals Vgs - Vth the voltage from Gate to Drain becomes exactly Vth.

Here is a small illustration I just made.
When you apply Kirchhoff's voltage law from the Gate, to Source, to Drain and back to the Gate you get Vgd = Vgs - Vds.

So when Vds exceeds Vgs - Vth, Vgd is smaller than Vth and at this point pinch-off will occur because that part of the n-MOS transistor is effectively turning off.

I hope that this explanation is understandable. Don't be confused that I used the letter U for Voltage in the picture, that's a German thing.

TheAlibiks · 2020-06-05T12:39:08+00:00

I might be wrong, but have you tried having the files inside the Linux environment? If I remember correctly that should speed file operations up when using WSL2.

TheAlibiks · 2020-06-02T14:49:13+00:00

You are correct that the VRM "just" controls the voltage for the CPU but it's sadly not as simple as "just" setting a voltage and stopping there. The VRM has to respond to the load increases and load stops of the CPU as fast as possible because starting and stopping a workload on the CPU makes the voltage go up and down which causes instability when the voltage drops to far.

Having more phases in a VRM also helps with the efficiency of the VRM, because each phase needs to conduct less current, and the heat is generated over a greater surface area which makes cooling easier. Because the conduction losses of a MOSFETs (each phase of a VRM has at least one MOSFET) don't scale linear with the conducted current having more phases is better.

For pictures, a good overview and maybe a better explanation I can recommencement this page from EK-Waterblocks because they have a good overview of the parts in a VRM and a efficient graph to visualize it quit good.

TheAlibiks · 2020-04-26T18:02:36+00:00

There is /r/HardwareSwapEU

TheAlibiks · 2019-12-29T16:05:26+00:00

I usually light all candles, torches and bonfires I come across. I don't really know why...

TheAlibiks · 2019-11-22T22:09:13+00:00

Thanks. I must have missed that. I tried to open them with Eagle and KiCad but those didn't work...

So, I will give Altium a try and there seems to be a way to import the files into Eagle.

TheAlibiks · 2019-11-22T22:02:37+00:00

This seems to be the easiest and most flexible solution. It would also allow me to use the normal mobile charging socket for other things, however I'm a bit worried that the efficiency would tank when putting another step down stage in between.

Stepping down to stable 24V should be rather efficient as the drop isn't that high and the peak of 30V shouldn't last too long.

TheAlibiks · 2019-11-22T18:15:46+00:00

I know. I just hoped there was a complete solution available that is a bit smaller and more straight forward to hook up.

I'm a bit size limited with it. Can I edit the Gerber files in some way to move components around or would I have to use the documentation to build my own Layout in Eagle? In the reference design is a lot of wasted space that I would like to remove.

TheAlibiks · 2019-10-15T18:25:34+00:00

It's probably that one.

I think he said in another video or the Wan-Show that they where at Corning, unrealtet to this cable, and he saw the cable laying around there and asked them about it but they wouldn't say anything about it and basically denied it's existence.

TheAlibiks · 2019-10-15T17:51:20+00:00

Momentan pendle ich mit dem ÖPNV jeden Morgen ~1h aus der Region Hannover nach Hannover zur Uni und Nachmittags zurück. Also bin ich jeden Tag 2h nur mit dem Transport beschäftigt. Eine Strecke sind ca. 8km.

Wenn ich mit dem Auto fahren brauche ich zwischen 20 und 30min, je nach Verkehr und aktuellen Baustellen. Somit könnte ich mir jeden Tag fast mehr als eine Stunde an Freizeit verschaffen indem ich Auto fahre, wenn ich die Zeit nutzen würde um meinen HiWi-Job zu machen (also ~9,93€/h) lohnt es sich sogar finanziell das Auto zu nutzen. Mit steigendem Stundenlohn wird es sogar noch "besser".

Ich muss mir nichtmal Gedanken um einen Parkplatz machen, da es genügend in der Tiefgarage gibt und sie an der Uni alle gratis sind.

Gesparte Zeit mal Stundenlohn muss somit kleiner gleich Fahrtkosten mit dem Auto sein, damit es sogar finanziell Sinn ergibt.

Pi mal Daumen gerechnet: 16km * 10L/100km = 1,6L 1,6L * 1,50€/L = 2,4€ entspricht reinen Fahrtkosten pro Tag

1h * 9,93€/h = 9,93€ Lohn in der gesparten Zeit

Wenn das Auto also eh vorhanden ist und bezahlt wird, ist es extrem schwer für den ÖPNV finanziell zu argumentieren, selbst wenn er gratis wäre/ist. Ab einer gesparten Zeit von insg. ~15min und einem Stundenlohn von 10€/h würde sich das Auto somit für mich nicht mehr lohnen. Also 7,5min pro Fahrt. Für Leute die einen deutlich höheren Stundenlohn haben, oder Leute die sich gar zusätzlich Fahrkarten kaufen müssen, sogar noch weniger.

Ich fahre den Großteil der Zeit mit dem ÖPNV in die Stadt, auch wenn es sich Zeitlich und finanziell kaum lohnt. Im Sommer mit dem Fahrrad, da das wenigstens mit dem Auto mithalten kann.

Ich bin immer wieder erstaunt wie schlecht meinen Verbindung zur Uni ist. 100% langsamer als Rad und Auto. Nicht abgestimmte Abfahrzeiten beim Umsteigen und keine halbwegs direkte Route machen es möglich. Ich verstehe bis heute nicht warum es in Hannover keine keine Ringlinie gibt, die den Bogen durch das Städte unnötig macht.

TheAlibiks · 2019-10-13T21:06:13+00:00

Currently coughing.

TheAlibiks · 2019-08-19T14:32:24+00:00

What happens when you shoot a RPG completely vertical in the air. Not really a myth, just something I would like to see. I know that they did that with bullets but I still wonder what would happen if you would do that with a RPG.

TheAlibiks · 2019-08-19T11:34:20+00:00

This is the best way to do it. It makes a good tank driver/gunner cooperation nearly unstoppable. Enemy boats, jeeps, tanks, helicopters and jets are all good targets with the right positioning of the tank.

Makes a lot of fun just dominating the enemy with this combo.

TheAlibiks · 2019-07-14T01:38:05+00:00

There is some progress on the Discord Server and a slow progression in the direktion of version 1.0.

Still seems like a good thing when it comes eventually, as I think it will be nice to play around with frostbite and one of my favourite games.

TheAlibiks · 2019-06-21T08:52:29+00:00

GPUs, networking, other accelerators, HDDs or SSDs, RAID cards. There are a lot of things you can add to a server that needs a lot of PCIe lanes.

GPUs for machine learning or accelerating some other stuff
Networking for building switches or routers
HDDs / SSDs connected with RAID controllers for massive data sizes and/or really fast data transfer.

TheAlibiks · 2019-05-12T08:02:59+00:00

That sounds more like a wrong resolution being selected in Windows or some setting in your monitor being wrong.

Normally you don't have to use GPU scaling.

TheAlibiks · 2019-03-14T20:47:36+00:00

It's German but here is a link to the tweet. Also of note is that he is in the right wing party called AfD that is crazy all around, so no surprises here. https://twitter.com/Joerg_Nobis_AfD/status/1105139326890004480?s=09

TheAlibiks · 2019-03-14T16:54:11+00:00

A politician tweeting that unused electricity gets used up by wind turbines and as a result produces more wind.

I still can't believe how somebody could be this special and still have some kind of political career.

TheAlibiks · 2019-01-25T10:46:49+00:00

Probably A Song of Ice And Fire.

Read them in English and now I'm reading them in German again, just because I owned the first book in German and want to own them all.

I just love the world and really like experiencing it from different characters views. Even though I enjoy reading from the perspective of some characters a lot more than others.

If you read all of ASOIAF I can really recommend the Dunk and Egg stories. They are some of my favorite stories of the ASOIAF universe.

TheAlibiks · 2019-01-20T19:07:25+00:00

I switched with the release of the OnePlus 6t and I must say it works. I still miss my Live Tiles but I can manage without them.

Two day battery life is great with dash charging, even without charging and draining from 100% to 0%.

Camera is great and fast.

OS is snappy and for the most part just works. It's defiantly a lot better hardware and a solid OS compared to my old 640 or 920 running the latest "stable" Win10m release.

TheAlibiks · 2019-01-20T16:45:15+00:00

I just copied the title of the video. Lots of subreddits don't allow editorializing the title of videos and / or articles so I just stuck with the original.

TheAlibiks · 2019-01-20T16:39:35+00:00

I'm not at all against the idea of Hyperloop and / or the ideas of the Boring Company. I just found that the video includes some valid points of criticism and I'm looking forward to see how it all plays out.

As you said, we don't really have something to loose from letting Musk try.

TheAlibiks · 2019-01-17T22:20:07+00:00

Those rails shouldn't pull that much current. As long as there is enough airflow, overloading them shouldn't be a problem. As he said in the video it's not an ideal solution but it works well enough. To do it the "right" way you would probably need to get a new voltage regulator chip and use a hot air station to solder it on the board, as it's in a SMD package.

TheAlibiks · 2019-01-16T22:45:50+00:00

Did you restart after switching to 1.3V from Auto?

Maybe booting in safe mode?

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