Hi In the US, you dig those systems up either via R/V outfits or from the guys who set up big boats (think water borne RVs rather than super tankers). The other source are the off grid solar guys. A lot depends on just how fancy a system you are after. With reasonable effort you can pick up systems up into the several 100 KW range.
Bob > On Oct 11, 2015, at 4:11 PM, Mark Spencer <m...@alignedsolutions.com> wrote: > > I've also seen inverter systems that are designed for stand by power use in > service at commercial sites in third world countries. Within reason they > basically let you run what ever reasonable arrangement of rechargeable lead > acid based batteries you want that will supply the required voltage and > current. They handle the conversion of dc to ac and the switch over from > commercial to inverter power. They usually also feature a basic battery > charger with settings to charge various types of batteries (ie, gel or > conventional lead acid.) > > Typically I've seen them used with a number of automotive style batteries. > > The users would need to sort out the necessary cables, fuses, batteries, deal > with safety considerations etc. > > I've never seen these devices in Canada or the U.S. Sort of a value > engineered UPS system for price conscious markets. Might be a nice starting > point for those who want to role their own system and can deal with the > safety aspects of this. I'm not sure what the transfer time from utility to > inverter power would be. > > In the U.S. and Canada the typical practice seems to be to use packaged UPS > systems that include their own batteries. > > > Sent from my iPhone > >> On Oct 11, 2015, at 10:36 AM, Bob Benward <rbenw...@verizon.net> wrote: >> >> Dave, >> You could use a 120V relay and switch the high capacity battery from its own >> charger to the battery pack in the UPS. When power comes back, the relay >> automatically switches the battery out and back to its own charger. >> >> Bob >> >>>>> -----Original Message----- >>>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr. >>>>> David Kirkby (Kirkby Microwave Ltd) >>>>> Sent: Saturday, October 10, 2015 6:07 PM >>>>> To: Discussion of precise time and frequency measurement >>>>> Subject: Re: [time-nuts] UPS for my time rack >>>>> >>>>>> On 10 October 2015 at 14:20, Chris Waldrup <kd4...@gmail.com> wrote: >>>>>> >>>>>> Hi, >>>>>> >>>>>> >>>>>> I have decided I'd like to get a UPS to put on the rack containing my >>>>>> Thunderbolt, the laptop that runs Lady Heather, and frequency counter. >>>>> >>>>> There's one issue with them that I don't see anyone mention. >>>>> >>>>> I was thinking of doing the same a while back, and intended getting a >> UPS >>>>> and adding a large external battery pack, so if the mains failed late at >> night, I >>>>> could run the GPS receiver and a few other things overnight, and >> consider >>>>> starting the generator in the morning. I contacted a dealer on eBay, >> who >>>>> specilaises in UPSs. He told me that the smaller units with built in >> batteries >>>>> will die if you put large external batteries on them. >>>>> Essentially the charging circuits are not designed to run as long as >> needed to >>>>> charge big batteries. Even on ones designed for external batteries, >> there's a >>>>> recommended limit on the size of them. So if you think you might want to >>>>> increase runtime by adding some batteries, buy one designed for that >> service. >>>>> >>>>> I've had two here which were HP/Compaq 5 kW units. These were different >>>>> to the normal, in that the batteries added up to over 300 V, so could >> produce >>>>> 240 VAC with no need to step it up. Both these blew up on me, for >> reasons I >>>>> never worked out. The load was never anywhere near 5 kW. >>>>> >>>>> Lots of people mention sine wave. Of course, if you keen enough, you >> could >>>>> make a class A amplifier and sine wave oscillator. The problem is that >> the >>>>> pure sine wave inverters tend to be very inefficient. >>>>> >>>>> As with most things, there are a lot of things to balance - runtime, >> cost, >>>>> quality of output, audio noise, RFI etc etc. >>>>> >>>>> Dave >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> ----- >>>>> No virus found in this message. >>>>> Checked by AVG - www.avg.com >>>>> Version: 2015.0.6140 / Virus Database: 4435/10788 - Release Date: >>>>> 10/09/15 >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
