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ESR's Newest Project: An Open Hardware/Open Source UPS (ibiblio.org)
An anonymous reader writes:
Last month Eric S. Raymond complained about his choices for a UPS (Uninterruptible Power Supply), adding that "This whole category begs to be disrupted by an open-hardware [and open-source] design that could be assembled cheaply in a makerspace from off-the-shelf components, an Arduino-class microcontroller, and a PROM...because it's possible, and otherwise the incentives on the vendors won't change." It could be designed to work with longer-lasting and more environmentally friendly batteries, using "EV-style intelligent battery-current sensors to enable accurate projection of battery performance" (along with a text-based alert system and a USB monitoring port).
Calling the response "astonishing," Raymond noted the emergence within a week of "the outlines of a coherent design," and in an update on GitLab reported that "The response on my blog and G+ was intense, almost overwhelming. It seems many UPS users are unhappy with what the vendors are pushing" -- and thus, the UPSide project was launched. "We welcome contributors: people with interest in UPSes who have expertise in battery technology, power-switching electronics, writing device-control firmware, relevant standards such as USB and the DMTF battery-management profile. We also welcome participation from established UPS and electronics vendors. We know that consumer electronics is a cutthroat low-margin business in which it's tough to support a real R&D team or make possibly-risky product bets. Help us, and then let us help you!"
There's already a Wiki with design documents -- plus a process document -- and Raymond says the project now even has a hardware lead with 30 years experience as a power and signals engineer, plus "a really sharp dev group. Half a dozen experts have shown up to help spec this thing, critique the design docs, and explain EE things to ignorant me." And he's already touting "industry participation! We have a friendly observer who's the lead software architect for one of the major UPS vendors." Earlier Raymond identified his role as "basically, product manager -- keeper of the requirements list and recruiter of talent" -- though he admits on his blog that he's already used a "cute hack" to create a state/action diagram for the system, "by writing a DSL to generate code in another DSL and provably correct equivalent C application logic."
He adds to readers of the blog that if that seems weird to you, "you must be new here."
Calling the response "astonishing," Raymond noted the emergence within a week of "the outlines of a coherent design," and in an update on GitLab reported that "The response on my blog and G+ was intense, almost overwhelming. It seems many UPS users are unhappy with what the vendors are pushing" -- and thus, the UPSide project was launched. "We welcome contributors: people with interest in UPSes who have expertise in battery technology, power-switching electronics, writing device-control firmware, relevant standards such as USB and the DMTF battery-management profile. We also welcome participation from established UPS and electronics vendors. We know that consumer electronics is a cutthroat low-margin business in which it's tough to support a real R&D team or make possibly-risky product bets. Help us, and then let us help you!"
There's already a Wiki with design documents -- plus a process document -- and Raymond says the project now even has a hardware lead with 30 years experience as a power and signals engineer, plus "a really sharp dev group. Half a dozen experts have shown up to help spec this thing, critique the design docs, and explain EE things to ignorant me." And he's already touting "industry participation! We have a friendly observer who's the lead software architect for one of the major UPS vendors." Earlier Raymond identified his role as "basically, product manager -- keeper of the requirements list and recruiter of talent" -- though he admits on his blog that he's already used a "cute hack" to create a state/action diagram for the system, "by writing a DSL to generate code in another DSL and provably correct equivalent C application logic."
He adds to readers of the blog that if that seems weird to you, "you must be new here."
Or replace the replaceable batteries, like you are SUPPOSED TO DO.
Sigh.
There's already a product that does this, it's been around for years. Actually there are lots and lots of things like this out there.
The killer isn't designing the thing, that's relatively straightforward ("relatively" meaning you need a couple of experienced EEs, 6-12 months, and $50K or so to get the kinks worked out). What's not straightforward is getting it manufactured in quantity and UL rated. Open source works OK for software where the "manufacturing" cost is zero and there's no need for any safety certification, but less well for anything else.
Do you mean the OpenUPS? It's DC only, and one of the hardest parts of ESR's UPS is the AC part. He needs it to run things like monitors that typically are not available in DC versions.
The AC part can be designed a number of ways, but from ESR's requirements it sounds like line interactive is required. The simplest way to do that is to take AC mains and convert it to DC. Use the DC to feed a DC to AC converter that produces the output AC voltage, and have a switch over mechanism in case the AC input goes away. Big caps to cover the gap during the switch over period. The DC also charges the battery when required.
As well as providing very good isolation of the output from the input, this method also makes it easier to handle various AC voltages and frequencies. The down side is that it is less efficient and much more complex than a simple switch-over system.
Designing such a system that can safely handle 1000W peak and say 500W continuous is not trivial. Getting it certified as safe is very expensive. Even the equipment to test such a design seriously will run into many tens of thousands of Euros/Dollars.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
I've worked this on both home and industrial side, and you're technically incorrect. Your policy will state that you meet all applicable building codes as one of the key items,
Stuff plugged into a wall outlet isn't subject to building codes. It's only if it's wired in.
Also keep in mind that UL stands for Underwriters Laboratories, where underwriters verify documentation to accompany a risk analysis for a policy. Insurance companies created UL for this very reason.
For the reason of assessing insurance risk for the corporations building the stuff, not the people plugging it in.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Nonsense.
I've built just about everything HeathKit offered, including their color TV, before they went out of business. There was/is NO clause in our home insurance policy that excludes electronic devices built by home owners. It does require that electrical repairs & additions, and plumbing work be done by licensed and bonded journeymen, which only makes sense. Our outlets have safety fuses which blow instantly in case you drop your electric shaver, hair dryer or hair curler in the sink full of water, preventing both fire and harm.
House circuits have 15 & 20 amp fuses which protect house circuits from over heating and fire in case a radio, TV, drill, saw, vacuum cleaner, etc., shorts out.
But, to your credit, if it means anything, you appear to be the first post.
Running with Linux for over 20 years!