> > *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. On Mon, May 16, 2016 at 4:28 PM, Harvey White <ma...@dragonworks.info> 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 <ma...@dragonworks.info> > >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 beagleboard+unsubscr...@googlegroups.com. > >> 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 beagleboard+unsubscr...@googlegroups.com. > 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. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CALHSORr8pWh47wzyi-jd_4U13X%2BfEDBj_r9Cf6Ao205AjYrX%2Bg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
