Oh, and the 120v is totally optional.   the 12v/5v out works fine without ever turning the inverter on. Separate circuits. 

But if you really are just dead set on building one:

Some (12v ) batteries on shelves to supply enough current for the time you want it to run during blackout + a cheap ( 20 bucks ) solar charge controller to charge them = ups.    Don't need to add the inverter. Controller takes 12v DC like you want to feed it anyway, and will charge your batteries.  Ya it says 'solar' but that is only because its runs on 12v in/out, which is what most panels do.. Its not 'special' or anything, just convenient. 

Just be sure to tap off the charging side instead of the 'official output' to run to your devices then its pass thru. Most will drop "official output" power for an instant during the outage and you dont want that, but tapping off incoming takes care of that..

Now, id not be trying to run my house like that.. but for what you are doing, its fine.

I have, but these days id not bother id just get those portable devices and stick it on a shelf. In my case i do want the 120v, but the 12v works fine too.   

Now if i wanted to run a KW of machines in some sort of mission critical data center, perhaps id build it. But you were not talking much of a power drain. So why go overboard and over-engineer things? The one in the link would run several hours, and would not need more than one.  If i was in the same boat, personally its not worth the effort when all i would need to do is cut a few cables ( for daisy chaining it up the rack ). 

Tho my needs are slightly different here, it would serve the same purpose if i was going to tie them to the generator too for extended use ( i dont, let it go down ).  My real use case is just to get by the slight blips we have here often, and a controlled shut down if it dont come back.  At one point i cheated and got a cheap UPS for that, since its got the USB monitor. 

My real use for these sort of batteries is to power the fridge, wives O2 machine, couple of fans. etc. at night so i dont run the noisy ass generator at 2AM..  So simple + portable = win for me.   My generator has 12v out too, so i can charge up the batteries for that night if needed. But on sunny days solar is plenty, not so sunny or if i need extra power ( it will push close to 5k. not a lot but plenty for our needs ), then its generator.  But i will turn off all non-essentials in the house.   ( helps we have gas heat/cooking/water ). But with the 12v out.. seemed like an easy match for what you wanted. 

Sat Mar 30 2024 20:03:19 EDT from IGnatius T Foobar

Right ... I should have clarified that what I want to do would be in the spirit of a telecom rack, if you've ever seen one of those.

i suppose it would be possible. But its not running, unless you turn it on.  I have a couple of different styles, and you have to intentionally turn that on....  so not sure why you would care. 

Mon Apr 01 2024 18:42:18 EDT from IGnatius T Foobar

I wonder if it would be possible to add a switch to *really* cut the supply to the inverter?

Right the inverter is totally optional on these things.  Dont turn it on, its not going t use any juice.  Sure, its 'there' but if its off.. does it matter?  And sure, you can build one, but once you add up cost of parts, its not much more to get a nice pretty package. Add a bit for your labor, you are in the hole. 

the only advantage of the one i built is i could always run wire to a bank of car batteries or something in a super emergency.  But its hacked together, heavier, and i saved perhaps 50 bucks...  ( in your case the 'box' dont matter, its going on a shelf, where i wanted mine to be portable, but you get the idea )

And not saying the one i sent the link for is 'it' but its one example of many.  Just choose the amperage you want, and make sure it does pass-thru... 

Fri Apr 05 2024 16:28:38 EDT from IGnatius T Foobar

i suppose it would be possible. But its not running, unless you turn
it on.  I have a couple of different styles, and you have to

Well if you have to turn it on, then that would imply that "the switch" is already built in and I don't have to add it.

So about $300 for an appropriate size "solar generator." I still feel like there ought to be a way to float a charge across an SLA battery with just a few parts if the source and load are both already 12 volts.

Oh and i tossed an egg your way for calling it a solar generator :P 

The ones 'for' solar normally only nativity charge via 12v since they are 'made' for solar, but can also handle car lighter ( err 'accessory' ) plug, 12v gas, whatever.  They normally come with 60watt or so wall warts for wall charging inside the house, but most will accept 100watt or more to charge from ( to accommodate larger solar panels )..  ( the one i built, i added 2 input charge ports.. )

My thought was just use whatever you were going to use for 120v to 12v for the servers in the first place and stick this in the middle to get it to be uninterruptible. 

Fri Apr 05 2024 23:41:59 EDT from IGnatius T Foobar

Oh and i tossed an egg your way for calling it a solar generator :P 

Hey, I put it inside sarcasm quotes! I have a real generator that runs on diesel fuel!

But yes, if I got one of those battery things and if it could accept 120VAC mains and 12VDC input at the same time, I could get a couple of solar panels later on and use them to offset the power costs. And I could tie it in to the 12VDC output of my (real) generator. Actually that would be pretty cool,


because my generator's 12VDC output is mechanically and electrically separate from its 120VAC output.

ooooo ( from news i saw this morning ) assuming we dont all die from WWiii this fall, 2025 is going to be the year RISC-V really takes off and becomes mainstream for the masses.

Google has also contracted with sifive for all their "internal silicon, including TPU". so i assume that means slow migration of all their data centers, and AI stuff.

"X-Silicon Inc. (XSi) has created a new RISC-V microprocessing chip architecture that combines a RISC-V CPU core with vector capabilities and GPU acceleration into a single chip. The CPU/GPU hybrid chip is open-standard and will reportedly be open-source as well, Jon Peddie Research reports, and it's designed to handle a variety of different functions, including AI, which dedicated CPUs and GPUs would normally handle."

Figures. That company who was making some super state of the art NPUs have stopped selling chips. Decided just to build a data center and sell access to AI model running on them.  

Bleh. So sick of walled gardens.

After checking out Techmoan's latest RISC-V video I learned that it might actually be the next big thing in "AI" (always, always, always put "AI" in quotes because it is neither artifical nor intelligent).

And that makes sense.  High density RISC-V could commoditize massively-parallel computing faster, cheaper, and with more versatility per watt than that is currently being done with repurposed video chips.  Steering the market away from an Nvidia monopoly?  Yes please.  Building inference algorithms that don't have to restrict themselves to instructions a video chip can execute?  Yes yes, please.  Rapidly speeding towards a state where massively parallel algorithms no longer require a room full of watercooled equipment?  Yes yes YES please.

As has been the case with everything else, the big tipping point comes when it's in everyone's hands at commodity prices.  Just as the really cool stuff in computing happened after we moved off the mainframe, the really cool stuff in high density algorithms will happen after we move off the cloud.  As everyone knows (and as many agree), I absolutely abhor the idea of all computing being consolidated into the data centers of a few tech giants.

that really isn't new or news.  Forgetting RISC for a moment, ASIC in the form of TPU/NPU/APU  have been around a while, but things are improving quickly and the advancements of LLMs and the attention they are getting now means there is a true market for big ones, not just little Edge stuff like we have had for a while, nearly everywhere ( just no one noticed )

Google ( home of TPU ) has data centers full of them.  " tensor processor unit " Tensors are the current 'thing' for language model AI, and pattern recognition.  I have a standalone Edge TPU ( they run tensor flow lite.. so reduced instruction set ) which is amazingly fast. 

GPU really only as a couple of advantages: is its here 'now' and true, you can buy huge ones.  right now.. . However its advantage is starting to crack as size and power requirements, ASICs eat GPU for lunch.   Just look at the crypto world. same thing happened there.  GPU got it going, and once the market was there, ASIC ate its lunch.    The only other advantage GPU will have is if the underlying architecture of LLMs change. ASIC will be useless at that point and have to start over. But GPU can adapt with code.

I know i have told these stories before about ASIC. but having lived thru it with crypto first hand, its taking the same path, so will have the same future. 

And yes.  NVIDIA can suck it.  But they are starting to add TPU like components to their high end GPUs, so even they see the light and are trying to adapt before its too late.

Wed Apr 10 2024 16:54:33 EDT from IGnatius T Foobar

  Building inference algorithms that don't have to restrict themselves to instructions a video chip can execute?  Yes yes, please.  Rapidly speeding towards a state where massively parallel algorithms no longer require a room full of watercooled equipment?  Yes yes YES please.

 

Ok as much as i hate NVIDIA, for the time being i wish i had an A100.  or even a H100.  at least until the bigger T/NPUs are availble to the common serfs.

Trying to run some models today, just cant do it unless i at least have 24gb on ONE card.  It wont spread it across my 2 cards.