On Mon, 16 May 2016 16:34:28 -0700, you wrote: >> >> *The bottom line seems to be that the BBB was not designed for this* >> * kind of situation or application, and making it fit this requires* >> * additional resources of some sort. Now the question comes down to* >> * cost, utility, percentage of applications needing this, elegance of* >> * design, and whether or not the hardware platform can cooperate in this* >> * or whether or not it simply lives in its own world.* >> >> >> * Harvey* >> > >I think the real bottom line is that the BBB *could* have been designed to >do all this and more. At additional costs. As Gerald has stated many times >on this group. Which I can completely understand. >
Exactly. Now this demonstrates the difference between a hobby project (where cost is secondary) and a commercial product, where cost is a goal, if not a limit. Had I designed it, it would have had a graceful shutdown procedure..... 1) had I thought of it 2) had I had the need for it 3) had I figured out how to do it (after X tries, depending) 4) had I decided it was important enough to do (bearing in mind 1 through 3 above) 5) fill in other limits as needed.... Second guessing a design is easy. However, it does show that any design (like plans of war) rarely survives contact with the enemy..... Harvey > > > >On Mon, May 16, 2016 at 4:28 PM, Harvey White <[email protected]> >wrote: > >> On Mon, 16 May 2016 15:45:14 -0700, you wrote: >> >> >You do not need anything connected to the beaglebone for any reason. The >> >beaglebone has an on die ADC that can detect if the AC mains is powered or >> >not. In which case, after a preset time period the Beaglebone could shut >> >its self down. >> >> True enough. The prevailing wisdom was going with an external device >> having all the smarts about power failure, while the BBB was being >> held up by batteries. >> >> The requirement that you propose is that the BBB have, somewhere, >> access to power long enough to do a graceful shutdown. >> >> How this is done is left as an exercise for the student. >> >> >> > >> >Meanwhile, an external "device" can just switch off the input 5V to the >> >beaglebone after a preset amount of time. Then once you have AC power >> back, >> >the "Device" simply turns the 5V back on. >> >> Yep, and with the same requirements of powering from either a battery, >> a supercapacitor, or something more exotic. >> >> The bottom line seems to be that the BBB was not designed for this >> kind of situation or application, and making it fit this requires >> additional resources of some sort. Now the question comes down to >> cost, utility, percentage of applications needing this, elegance of >> design, and whether or not the hardware platform can cooperate in this >> or whether or not it simply lives in its own world. >> >> >> Harvey >> >> >> > >> >On Mon, May 16, 2016 at 3:09 PM, Harvey White <[email protected]> >> >wrote: >> > >> >> On Mon, 16 May 2016 11:35:54 -0700 (PDT), you wrote: >> >> >> >> >Looks like nut been ported to Debian for the BBB. >> >> > >> >> >It and a smart UPS might be the easiest solution. >> >> > >> >> >I'm thinking along these lines, but haven't done anything with it yet. >> >> The >> >> >nut client getting a signal over the network from my desktop is kind of >> >> >what I'm thinking. I've my BBW IOT app, router, and ISP interface on >> >> >a separate UPS that I want running as long as the battery lasts, but a >> >> >controlled shutdown of the BBW is something I'd like to add eventually. >> >> > >> >> >The "shutdown if the power outage lasts longer than X" is pretty easy, >> >> >robust automatic start-up when the power returns might require a >> smarter >> >> >than the average UPS. >> >> >> >> I'd say that you want one that does automatic battery tests as well. >> >> The one that I knew of at one time was a sine wave inverter. >> >> >> >> To summarize the types of inverters, there are two schemes. >> >> >> >> 1) keep a battery charged at all times. When power fails, detect the >> >> loss of AC at the output. Start the inverter and switch that power to >> >> the output of the inverter. What happens is that power drops out for >> >> the output with a power failure, and your equipment is supposed to >> >> stay "up" for a certain amount of time (that the UPS takes to switch >> >> on). Then the UPS takes up the load and life is good. >> >> >> >> 2) keep a battery charged at all times. Power the inverter from the >> >> battery at all times. When the power fails, the battery charger >> >> simply shuts down. >> >> >> >> The second one is the one I'd think you'd want to get. >> >> >> >> An opto isolator, driven by an AC bridge (or an AC style optoisolator) >> >> would give you a power failure indication within a half cycle. >> >> >> >> Harvey >> >> >> >> >> >> > >> >> >I'd be interested in success stories, but my experience with brand name >> >> >(APC) and off-brand UPS with desktop system is while they are better >> than >> >> >nothing, they aren't good at reporting battery issues and ultimately I >> >> end >> >> >up with a power failure and "pull the plug" type shutdown because the >> UPS >> >> >batteries can't support the switch over. We get a lot of 0.5 - 15 >> minute >> >> >power failures from thunderstorms here, so I'm sure the USP has saved >> me, >> >> >but they are not foolproof. >> >> > >> >> > >> >> >Ultimately I'm trying to sell the wife on a "whole house" natural gas >> >> >powered backup system so that a dumb UPS or battery with only a few >> >> minutes >> >> >run time to let the generator come on and switch over would be needed. >> >> >She was excited about it after Hurricane Ike, but now that its been >> ~eight >> >> >years, selective memory has her thinking we don't need it. >> >> >> >> -- >> >> For more options, visit http://beagleboard.org/discuss >> >> --- >> >> You received this message because you are subscribed to the Google >> Groups >> >> "BeagleBoard" group. >> >> To unsubscribe from this group and stop receiving emails from it, send >> an >> >> email to [email protected]. >> >> To view this discussion on the web visit >> >> >> https://groups.google.com/d/msgid/beagleboard/apfkjbtvsk9h94q0qvfpke40ofhbc7c22h%404ax.com >> >> . >> >> For more options, visit https://groups.google.com/d/optout. >> >> >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/beagleboard/silkjbt8elht0qlo1536jduujmhaekcobc%404ax.com >> . >> For more options, visit https://groups.google.com/d/optout. >> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. 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