So you'd rather lose power in wires instead?
Who cares about the wires when you're going to dissipate at least 160W from that 10 ohm resistor in series with the input, and have a 40V drop to go with it?
And explain again how you keep an input ripple of less than 3% when you will be dropping anywhere from 0 (no load) to 40 (full load) volts on that 450V input?
Oh, absolutely yes in data centers. But not in houses.
If this is intended for houses, then you certainly have sufficient space for a shoebox or larger sized inverter. I have several of them in my house -- they're called a UPS, and a couple of them are 1.5kW. I haven't spent the money or they could be larger.
This challenge turns out to be to convert 450DC into 240VAC true-sine-wave. The intent seems to be to waste time converting DC into AC so it can be converted back into the DC needed to run the electronics. A lot of the items shown in the challenge don't inherently need AC, and some of them only need AC because they were built with AC motors in them. The laptops, TVs, monitors, desk lamps, toasters, automobile, radios, coffee makers -- all can be trivially designed to use AC or DC. (In fact, the very first radios sold in the US were AC/DC. That's because the AC/DC power wars weren't over yet.)
And even the excuse that converting from one DC voltage to another is harder than AC conversions is long gone. There are so many DC/DC converters in use today that nobody can seriously argue that those conversions are anything but trivial. When all we had were linear regulators it was inefficient to lower the voltage and hard to increase it, but with switching buck and boost regulators now ubiquitous that concern is moot.
So. Other than "it is cool", I still ask "why"? This size of device would be required for portable use, perhaps in poorly developed areas, but who is going to be carrying 450DC with them and need 240AC true-sine-wave to power the microwave in their pocket?
1. Small size and small heat output mean efficiency.
No. Efficiency in conversion translates to efficiency. You can have a box the size of a car that is is 95% efficient. And high efficiency means low heat output, not the other way around. I can build an inverter that is 0% efficient and remains at room temperature. I usually throw them out when the efficiency drops like that.
2. KW efficiency will likely translate directly to small scale device efficiency.
There are already very efficient small scale devices.
3. If its small enough, new ways of moving power could be theoretically created.
Inverters don't move power, they convert it from one form to another. In this case, it is converting 450VDC to 240 AC true-sine-wave. It's already dealing with only "the last mile".
This reminds me of the packaging wars of yore. "why would you want the packaging to be lighter and smaller and cheaper?"
This is nothing of the sort. "Lighter smaller cheaper" packaging has effects in resource use in production and shipping and sales of every item in that packaging. Having a tiny inverter does not. There was never a "packaging war".
Thanks. I turned it off, stop telling me to turn it back on.
1) I said "educational non-profit" - do you think there's a reason I used these two words together?
Because you think that non-profit schools have some special rights when it comes to "fair use" that students at commercial schools do not? And you're repeating this because you missed the fact that I wasn't specifically referring to a for-profit college use, thus it applies to non-profit just as much as for-profit? The fact is, I cannot simply duplicate college (non-profit educational use) textbooks and hand them out to my students and claim "fair use".
2) I'm well aware that there are other considerations for fair use (which is why linked to the page), one of them being impact on the market value of a work.
Another being whether the work is being used in its entirety; and/or for review or criticism. Copying an image verbatim as an illustration for a school paper fails these "fair use" criteria.
You can't honestly claim that a kid taking an image from google in order to use in their class work violates this.
I can and I do, because it does. I've already said why. The link you provided says there are FOUR considerations, and all of them must be met. If you are copying someone else's work into your schoolwork 1) in its entirety and 2) without the purpose of review or criticism of that content, you are outside the scope of fair use. And if you did it in a paper I ever graded, you better provide a cite for the source or I'll see that as a claim that it is your work, just as copying text from Wikipedia into your paper needs a cite or it would be plagiarism.
That doesn't mean that I think there is any purpose to be gained from suing those students who do it. A use can violate "fair use" and not be worth legal action.
but are you seriously arguing for throwing the baby out with the bathwater?
I don't see where I've mentioned any "throwing" of anything, only that your "educational non-profit" criterion is insufficient to determine "fair use", and I provided a trivial example to that demonstrates that fact.
(i.e. for a few asshats we'll just destroy the value of the resource for everybody)
I'm sorry, but you've lost me here. Where did I say ANYTHING like that? Did I say we should shut down Google (or Wikipedia, or
I used to hold an attitude very much like yours, but I took some tests on this site
Congratulations, you've just been push-polled. Those tests aren't built to discover bias, they're built to convince you that you are biased.
How about we focus on those things that actually gets people hurt, like banksters taking chances with the economy and politicians using the army to play chicken-race.
Both a red herring AND a false dichotomy. Impressive!
In the case of smallpox what would happen is that the scientist screwing up might get infected and placed in quarantine.
What if he's immune, and, becoming a carrier, boards a plane?
Every time some man acts like an ass to some woman, it counters 10 men being perfectly civil. If you don't like it, try to keep your bro's in line. It turns out they're assholes, and no one likes assholes.
It turns out I neither have power, authority, or even influence over those "bros". So, you can take your collective guilt elsewhere; I'm not buying.
No one who wasn't literally insane would try to use smallpox as a weapon
Islamic extremists.
What's a "cis"? Sounds like a codeword of the intolerant to me.
You're part of the problem.
the common malcontent millennial armed with dozens of mod points around here, trained from birth to rail at every iniquity, but they are naive;
So, first you have a go at millennials for being worried about corruptiuon...
Between the `drug war,' our welfare state, piratic corporate governance and ever greater abuse of power by our government, we are rapidly catching up.
Then you say their worries are justified.
Which is it?
The "ghost cities" you talk about are actually gradually filling up as more population moves from rural settings into the cities - this has been a long term goal of the Chinese government, but their "long terms" are a fair longer than the "around next election time" terms that westerners tend to think in.
True, running a government is so much easier without that pesky democracy to get in the way.
The only "special" insult they make to women is rape, because they know that will piss them off.
Really? Did they stop threatening male players with buggery?
If the aborigine drafted an IQ test, all of Western civilization would presumably flunk it. -- Stanley Garn
