The large brick you have on all your tech when you plug it in is the converter. AC works great for some applications, none of them really technical in nature.
Data centers are transitioning from AC to DC
141–150 of 432 posts
Re: Data centers are transitioning from AC to DC
#142Waiting for home DC. It is silly to have AC to DC converters in all of my wall connected electronics ( LED bulbs, home controller, computer equipment etc )
Not going to happen. For the same reason that the US never converted to a higher domestic voltage even though there are many practical advantages. The transition from one system to another at the consumer level would be terrible, even if there would be some advantage (and I'm not sure the one you list is even valid, you'd get DC-DC converters instead because your consumers typically use a lower voltage than the house…
I'm not sure it's likely, but I could see DC lighting start to happen in new construction. Have a single AC-to-DC converter off the main service entrance that powers hard-wired LED lighting fixtures in the house. Would probably be better than running the individual (and usually very low quality) converters in dozens of standard LED light bulbs. Would need to be standardized, codified, etc. so probably not happening soon.
Re: Data centers are transitioning from AC to DC
#143Earlier quoted context omitted.
The lesser-known instance of this is RV power. When you're running off small batteries and solar, you want to make the best use of the watt-hours you have, and that means avoiding the DC-to-AC-to-DC loop wherever possible. So you run 12V (or in newer models, higher voltage) versions of everything, upconverting as necessary.
I am really skeptical that 12VDC power distribution in RVs actually saves power compared to a high-quality (hah!) higher voltage AC or DC system. 12V is absurdly low and you can’t easily lose quite a few percent in resistive losses even with fairly large cables, and those large cables are quite unpleasant to work with and rather dangerous.
I tried using a microwave off the RV batteries, your inverter needs 4/0 cable. Very "fun".
Re: Data centers are transitioning from AC to DC
#144800V to each rackmount unit, with hot plugging of rack units? That's scary. The usual setup at this voltage is that you throw a hulking big switch to cut the power, and that mechanically unlocks the cabinet. But that's not what these people have in mind. They want hot-plugging of individual rackmount units. GE has a paper about the power conversion design, but it doesn't mention the unit to rack electrical and mechan…
It is a pretty clever design > When it is detected that the PDB starts to detach from the interface, the hot-swap controller quickly turns off the MOSFET to block the discharge path from Cin to the system. After the main power path is completely disconnected, the interface is physically detached, and no current flows at this time > For insertion, long pins (typically for ground and control signals) make contact first…
Yes, I read that. There had better be a backup system. MOSFETs tend to fail ON, and there's a megawatt going into each rack.
Somehow this seems the wrong approach to AI.
Re: Data centers are transitioning from AC to DC
#145Earlier quoted context omitted.
This would be the funniest thing to do. 100K Amps is doable, the question is for how long. That would be one very impressive bank of capacitors. And to turn a 00 into plasma would have some spectacular side effects, such as raining molten copper across a sizeable area. Just your reading glasses would indeed not be enough, there probably isn't any PPE that I would consider entirely safe other than sufficient distance…
Ho ho ho, you asked for it: https://www.youtube.com/watch?v=OC7sNfNuTNU
See also (as posted elsethread): https://www.youtube.com/watch?v=RoGbrgOhPes
Re: Data centers are transitioning from AC to DC
#146Earlier quoted context omitted.
This would be the funniest thing to do. 100K Amps is doable, the question is for how long. That would be one very impressive bank of capacitors. And to turn a 00 into plasma would have some spectacular side effects, such as raining molten copper across a sizeable area. Just your reading glasses would indeed not be enough, there probably isn't any PPE that I would consider entirely safe other than sufficient distance…
Ho ho ho, you asked for it: https://www.youtube.com/watch?v=OC7sNfNuTNU
Holy crap. That's a whole series of bad ideas extremely well executed. That guy probably has never seen what a lead acid battery can do when it explodes. He keeps hiding away from the hot metal but in the path of ~half of those batteries. Ignorance is bliss.
That's low voltage lightning :)
Re: Data centers are transitioning from AC to DC
#147It is absolutely stupid to talk about this as edisons revenge. If Tesla had the modern high power transistors needed to get high voltage dc out of the ac produced from a spinning turbine he would be all for high voltage dc too. Tesla understood that high voltage was needed for efficient long range transmission. He also understood that transformers were the inly remotely efficient way to climb up to and down from thes…
sure, and also Montezuma didn't actually plan on diarrhea ruining people's vacations, but vernacular usage being what it is we have the phrase Montezuma's revenge.
I only found Edison in the headline, I didn't find it anywhere in the body, nor did I find Tesla. Glancing through the article it almost seems like someone tried to make a catchy headline to get clicks.
Re: Data centers are transitioning from AC to DC
#148Earlier quoted context omitted.
Not going to happen. For the same reason that the US never converted to a higher domestic voltage even though there are many practical advantages. The transition from one system to another at the consumer level would be terrible, even if there would be some advantage (and I'm not sure the one you list is even valid, you'd get DC-DC converters instead because your consumers typically use a lower voltage than the house…
I suppose that still begs the question somewhat, since the US does have 240V (2 phase) already driving many appliances. Why hasn’t it ever become standard for luxury kitchens to have a European-style outlet for use with a European kettle? I know the US already has a different 240V plug shape, so it might have to be an unlicensed installation, but surely someone wanted hot tea faster and did that calculus before?
Most important comment here!! I would love to buy like a 6kw battery induction kettle for the states. As far as I can tell, they don’t exist.
Re: Data centers are transitioning from AC to DC
#149Our houses should be DC. So wasteful to have all these bricks to change to AC to DC.
I'm renovating a house, and have been considering 24V or 48V DC outlets in a few rooms. Semiconductors become more expensive above ~32V, so 24V might be the sweetspot.
However, there's also PoE (24 or 48V!), so maybe that's the right approach. It's not like each outlet is going to run a heater anyway.
Re: Data centers are transitioning from AC to DC
#150It is absolutely stupid to talk about this as edisons revenge. If Tesla had the modern high power transistors needed to get high voltage dc out of the ac produced from a spinning turbine he would be all for high voltage dc too. Tesla understood that high voltage was needed for efficient long range transmission. He also understood that transformers were the inly remotely efficient way to climb up to and down from thes…
It was Westinghouse who pushed the AC grid against his rival Edison's DC approach. Tesla was a minor figure working for both of them for a bit.