By "momentary outage", I mean momentary loss of power. Like a dip, a drop, a sag, whatever you want to call it. I have a 1200 W line conditioner because for overkill. I guess it might help increase the momentary outage protection. Other stuff flickers, but not stuff connected to the line conditioner (like my PC or its monitor). Even if it doesn't help, it doesn't hurt. It's worked great without having to mess with a battery. When the power does go off for more than a second, the PC stays off instead of Windows rebooting. But that hasn't happened in years. That line conditioner with its clicking sound and LEDs also keeps one aware of room/house/neighborhood voltage. I like being aware of stuff. Fred Bloggs <bloggs.fredbloggs.fred@gmail.com> wrote:> On Saturday, June 25, 2022 at 1:24:40 AM UTC-4, John Doe wrote: >> Jan Panteltje <pNaonSt...@yahoo.com> wrote: >> > bob prohaska wrote: >> > >> >>I'm setting up a UPS for my computer/comms equipment using an >> >>inverter/charger and battery from Amazon. The equipment draw is only >> >>about 40 watts measured with a Kill-A-Watt, but all the associated >> >>wallwarts use capacitive-input switching power supplies. That means >> >>they only draw current at line peaks. >> >> >> >>My seat-of-the-pants guess is that the duty cycle is around 10%, meanin > g >> >>that the average 40 watts is really 400 watts 10% of the time. That's > >> >>well within the continuous power rating of the inverter, which is 800 > >> >>watts, so it's likely the setup will work as it is. >> >> >> >>The question is: Can the peak load be made closer to the average load b > y >> >>putting an inductor in the AC line feeding the wallwarts? >> >> >> >>If anybody's been through this exercise I'd be grateful for guidance. >> > Interesting question, my cheap UPS seems to put out a square wave I >> > wondered if the flat tops are actually not better for the wall warts as > >> > the charging part is longer than with a sine wave top... Been working > >> > now fine for a year or so with this thing, comes in almost every day >> > these days with mains company fiddling,.. flashing light bulbs sometime > s >> > here too. To backup for longer times I have a pure sine wave 2 kW >> > converter and a 250 Ah lifepo4 battery.. So I can keep watching sat TV > >> > or even cook food. More than 10 wallwarts on that UPS now, some >> > Raspberry Pi, some USB hubs, some cameras., also security recorder, >> > monitors... .. audio amp... 4 TB harddisks... I would personally not >> > bother with a a series inductor... >> For a personal computer only... I use a Tripp-Lite LC1200. No battery at > >> all. I don't recall the last time we had a power failure that lasted more > >> than an moment. But there has been flickering. The line conditioner works > >> great for momentary outages, no messing with a battery. >> >> Of course that doesn't suit everybody. > > They just lifted the same technology used in inverter generators. If it coasts through what you call a momentary outage then it wasn't an outage. The price is pretty good but then again 1200 Watt is not really that much. Are you mining bitcoins or something? What in the world kind of computer setup requires 1200W these days... >
Inverters vs wallwarts
Started by ●June 24, 2022
Reply by ●June 27, 20222022-06-27
Reply by ●June 28, 20222022-06-28
On a sunny day (Mon, 27 Jun 2022 09:42:08 -0400) it happened legg <legg@nospam.magma.ca> wrote in <mlbjbhp55bpidiekuu6pjjsk607695aths@4ax.com>:>On Sat, 25 Jun 2022 07:32:27 -0400, legg <legg@nospam.magma.ca> wrote: > >>On Sat, 25 Jun 2022 02:10:59 -0000 (UTC), bob prohaska >><bp@www.zefox.net> wrote: >> >>>I'm setting up a UPS for my computer/comms equipment using an >>>inverter/charger and battery from Amazon. The equipment draw >>>is only about 40 watts measured with a Kill-A-Watt, but all >>>the associated wallwarts use capacitive-input switching power >>>supplies. That means they only draw current at line peaks. >>> >>>My seat-of-the-pants guess is that the duty cycle is around 10%, >>>meaning that the average 40 watts is really 400 watts 10% of the time. >>>That's well within the continuous power rating of the inverter, which >>>is 800 watts, so it's likely the setup will work as it is. >>> >>>The question is: Can the peak load be made closer to the average >>>load by putting an inductor in the AC line feeding the wallwarts? >>> >>>If anybody's been through this exercise I'd be grateful for guidance. >>> >>>Thanks for reading, >>> >>>bob prohaska >>> >>> >> >>I did some passive correction for off-the-shelf 60Hz linears in >>the 80s. Best effects achieved using a saturable choke and >>quasi-resonant capacitor, over a limited range of power levels >>for any specific installation. >> >>The parts are generally impractical for a hobbyist to get >>ahold of, though restacking laminations from unvarnished scrap >>is possible. Requires good VP Impregnation to silence the >>final iteration. >> >>The actual current phase angle shifted from leading to lagging >>over the useful range. Output voltage into the 60Hz capacitive >>load was flat-topped, affecting the low-line voltage performance. >>The choke/cap combination supported the output difference >>during line current reversal. >> >>It's no good guessing what the current waveshape is; you've >>got to measure it / scope it. Line current transformers are >>pretty cheap these days, often included in <$10 wattmeters >>from off-shore sources. A scope is useful, but more expensive. >> >>A lot of modern wall-warts are actually PFC compliant, through >>the use of dedicated low power integrated controllers. These >>employ valley-fill or critical-conduction (FM) off-line switchers >>economically, at power levels as low as 5W. >> >>Don't guess. Measure. Read specs of devices involved. >> >>Don't go overboard. Your UPS output may be more tolerant of peak >>loads than you assume, and your loads may be less peaky, simply >>due to industry commodity trends and available parts. >> >>RL > >Some work on different rectifier and filter/pre-filter circuitry >was published by Richard Redl and Laszlo Balogh ~1995. >Some notes I made in the 80s, on the simplest LC configuration >are also included in this zip file. > >In the latter, the effect of series choke saturation at above- >nominal loads is illustrated. > >http://ve3ute.ca/query/passive_power_factor_diag.zip > >When standards docs start talking about total harmonic distortion >and specs include power factors >95%, you can pretty much rule out >passive approaches. They can be simple, reliable, quiet and >effective in reducing generator and interconnection losses. >. . . which is the OP's actual concern. > >RLI did some back of the envelope calculation on (well actually I used wcalc) how much the input elctrolytic in a 12 W (12 V 1 A) wallwart discharges between mains periods with a bridge (so 10 mS here in 50 Hz land) IIRC that was about 57 volt ripple! on that tiny cap (usually 4.7 uF / 400 V type). No wonder all those electrolytics fail (have repaired many wallwarts here, BTW I also use floorwarts: http://panteltje.com/pub/floor_warts_IXIMG_0790.JPG all that on same UPS too. Primary cap discharge current between mains peaks: Given secundary 12 V 1 A and 350 V on primary cap 12 / 350 = 34 mA, but taking into account efficiency say 50 mA then if cap is 5 uF and t = 10 mS As Q = C.U = i.t -> U = i.t / C = (50E-3 * 10E-3) / 5E-6 = 100 V ripple! 50 V ripple for a 10 uF... 4.7 uF 400 V seems to be the normal in those small wallwarts (5 V 1 A), so I have a bunch of those, and also some big ones for the secondary caps, those often get puffed too. Maybe I goofed the math, but next time one goes I will scope that ripple Normally you can visually spot those bad caps because they will all be swollen. Anybody measured the ripple?
Reply by ●June 28, 20222022-06-28
Jan Panteltje wrote more rubbish: --------------------------------------------------------> > I did some back of the envelope calculation on (well actually I used wcalc) > how much the input elctrolytic in a 12 W (12 V 1 A) wallwart discharges > between mains periods with a bridge (so 10 mS here in 50 Hz land) > IIRC that was about 57 volt ripple! on that tiny cap (usually 4.7 uF / 400 V type). >** So 15% p-p ripple. ( 57/340) Nothing odd about that.> No wonder all those electrolytics fail .....** Bullshit.> Anybody measured the ripple?** Why ? An any case, most plug-pak supplies operate well below their max current ratings. If electro caps fail early - it is due to internal temp rise only. Plus the use of cheap as possible parts. ..... Phil
Reply by ●June 28, 20222022-06-28
On a sunny day (Tue, 28 Jun 2022 03:42:04 -0700 (PDT)) it happened Phil Allison <pallison49@gmail.com> wrote in <38a7b4bd-81b5-42d3-a9a9-de151a557414n@googlegroups.com>:> Jan Panteltje wrote more rubbish: >-------------------------------------------------------- >> >> I did some back of the envelope calculation on (well actually I used wcalc) >> how much the input elctrolytic in a 12 W (12 V 1 A) wallwart discharges >> between mains periods with a bridge (so 10 mS here in 50 Hz land) >> IIRC that was about 57 volt ripple! on that tiny cap (usually 4.7 uF / 400 V type). >> > >** So 15% p-p ripple. ( 57/340) > Nothing odd about that.Well the same thing is specified from 110 V to 230 V AC So double the current and the ripple AGAIN when used in a 110V world (ut 60 Hz is 5/6 * 10 mS so that helps.>> No wonder all those electrolytics fail ..... > >** Bullshit.Do not eat it! Live on a farm?>> Anybody measured the ripple? > >** Why ?Why do humming beans exist? Why is water wet?>An any case, most plug-pak supplies operate well below their max current ratings.For example the raspberry supplies, when more things are plugged into the USB are maxed out That is why I have now 2 USB hubs on the Pi4s each has its own supply.>If electro caps fail early - it is due to internal temp rise only.The elcos get hot because of the high ripple current creating heat and detoriation of the cap, creating more heat ... a run-away process.>Plus the use of cheap as possible parts.Sure good electrolytics are expensive. Bigger ones too -:)
Reply by ●June 28, 20222022-06-28
Jan Panteltje is a fucking IDIOT wrote: =============================> > > > >** So 15% p-p ripple. ( 57/340) > > Nothing odd about that. > Well the same thing is specified from 110 V to 230 V AC > So double the current and the ripple AGAIN when used in a 110V world (ut 60 Hz is 5/6 * 10 mS so that helps. > >> No wonder all those electrolytics fail ..... > > > >** Bullshit. > > Do not eat it! Live on a farm?** Fuck you - imbecile.> >> Anybody measured the ripple? > > > >** Why ? > > Why do humming beans exist?** So you have no reason at all ? zzzzzzzzz... > >An any case, most plug-pak supplies operate well below their max current ratings.> > For example ....** Yawwnnn - more false logic idiocy.> >If electro caps fail early - it is due to internal temp rise only.> The elcos get hot because of the high ripple current creating heat and detoriation of the cap,** Not at 15% they fucking don't - you liar.> >Plus the use of cheap as possible parts.> Sure good electrolytics are expensive.** Yawwnnn - more false logic idiocy. Scuse me while I vomit. ..... Phil
Reply by ●June 28, 20222022-06-28
On Tue, 28 Jun 2022 08:10:11 GMT, Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote:>On a sunny day (Mon, 27 Jun 2022 09:42:08 -0400) it happened legg ><legg@nospam.magma.ca> wrote in <mlbjbhp55bpidiekuu6pjjsk607695aths@4ax.com>: > >>On Sat, 25 Jun 2022 07:32:27 -0400, legg <legg@nospam.magma.ca> wrote: >> >>>On Sat, 25 Jun 2022 02:10:59 -0000 (UTC), bob prohaska >>><bp@www.zefox.net> wrote: >>> >>>>I'm setting up a UPS for my computer/comms equipment using an >>>>inverter/charger and battery from Amazon. The equipment draw >>>>is only about 40 watts measured with a Kill-A-Watt, but all >>>>the associated wallwarts use capacitive-input switching power >>>>supplies. That means they only draw current at line peaks. >>>> >>>>My seat-of-the-pants guess is that the duty cycle is around 10%, >>>>meaning that the average 40 watts is really 400 watts 10% of the time. >>>>That's well within the continuous power rating of the inverter, which >>>>is 800 watts, so it's likely the setup will work as it is. >>>> >>>>The question is: Can the peak load be made closer to the average >>>>load by putting an inductor in the AC line feeding the wallwarts? >>>> >>>>If anybody's been through this exercise I'd be grateful for guidance. >>>> >>>>Thanks for reading, >>>> >>>>bob prohaska >>>> >>>> >>> >>>I did some passive correction for off-the-shelf 60Hz linears in >>>the 80s. Best effects achieved using a saturable choke and >>>quasi-resonant capacitor, over a limited range of power levels >>>for any specific installation. >>> >>>The parts are generally impractical for a hobbyist to get >>>ahold of, though restacking laminations from unvarnished scrap >>>is possible. Requires good VP Impregnation to silence the >>>final iteration. >>> >>>The actual current phase angle shifted from leading to lagging >>>over the useful range. Output voltage into the 60Hz capacitive >>>load was flat-topped, affecting the low-line voltage performance. >>>The choke/cap combination supported the output difference >>>during line current reversal. >>> >>>It's no good guessing what the current waveshape is; you've >>>got to measure it / scope it. Line current transformers are >>>pretty cheap these days, often included in <$10 wattmeters >>>from off-shore sources. A scope is useful, but more expensive. >>> >>>A lot of modern wall-warts are actually PFC compliant, through >>>the use of dedicated low power integrated controllers. These >>>employ valley-fill or critical-conduction (FM) off-line switchers >>>economically, at power levels as low as 5W. >>> >>>Don't guess. Measure. Read specs of devices involved. >>> >>>Don't go overboard. Your UPS output may be more tolerant of peak >>>loads than you assume, and your loads may be less peaky, simply >>>due to industry commodity trends and available parts. >>> >>>RL >> >>Some work on different rectifier and filter/pre-filter circuitry >>was published by Richard Redl and Laszlo Balogh ~1995. >>Some notes I made in the 80s, on the simplest LC configuration >>are also included in this zip file. >> >>In the latter, the effect of series choke saturation at above- >>nominal loads is illustrated. >> >>http://ve3ute.ca/query/passive_power_factor_diag.zip >> >>When standards docs start talking about total harmonic distortion >>and specs include power factors >95%, you can pretty much rule out >>passive approaches. They can be simple, reliable, quiet and >>effective in reducing generator and interconnection losses. >>. . . which is the OP's actual concern. >> >>RL > >I did some back of the envelope calculation on (well actually I used wcalc) >how much the input elctrolytic in a 12 W (12 V 1 A) wallwart discharges >between mains periods with a bridge (so 10 mS here in 50 Hz land) >IIRC that was about 57 volt ripple! on that tiny cap (usually 4.7 uF / 400 V type). >No wonder all those electrolytics fail (have repaired many wallwarts here, >BTW I also use floorwarts: > http://panteltje.com/pub/floor_warts_IXIMG_0790.JPG > all that on same UPS too. > >Primary cap discharge current between mains peaks: >Given secundary 12 V 1 A and 350 V on primary cap 12 / 350 = 34 mA, >but taking into account efficiency say 50 mA then if cap is 5 uF and t = 10 mS >As Q = C.U = i.t -> U = i.t / C >= (50E-3 * 10E-3) / 5E-6 = 100 V ripple! >50 V ripple for a 10 uF... > >4.7 uF 400 V seems to be the normal in those small wallwarts (5 V 1 A), so I have a bunch of those, >and also some big ones for the secondary caps, those often get puffed too. > >Maybe I goofed the math, but next time one goes I will scope that ripple >Normally you can visually spot those bad caps because they will all be swollen. > >Anybody measured the ripple?Electrolytic life is rms current dependent, among other things (like temperature). If you convert your delta-voltage into current, you'll get a more meaningful value that can be compared to published ratings. Higher currents actually occur during the cap charging period and high peak-to-average current ratios can give punishing rms values for the same average filter output current. Electrolytics normally have a predicted life some orders of magnitude shorter than most other components - and they are the main non-moving parts that determine of predicted MTBF in commercial products running off the AC line, through a rectified filter. There have been eras where bad mfr formulations, misapplication of product and simple bad design made early mortality abnormally evident. RL
Reply by ●June 28, 20222022-06-28
legg wrote: ================ ** Learn to trim - asshole.> > >Anybody measured the ripple? > > Electrolytic life is rms current dependent, among other things (like > temperature).** You just made that mad crap up. Temp is the single determining factor on expected life. Almost always the local ambient completely dominates.> Electrolytics normally have a predicted life some orders of > magnitude shorter than most other components** Then in practice often outlast the lot. The one exception being vacuum tubes. ..... Phil
Reply by ●June 28, 20222022-06-28
Phil Allison <pallison49@gmail.com> wrote:> bob prohaska wrote: > ====================== >> >> AIUI, current into a capacitor is dv/dt x C, so the square wave should >> be much worse in terms of peak current than my sine-wave case. >> > ** Nope - a rectified square wave is pure DC. > SMPSs used in pro-audio power amps are nearly all square wave inverters. >Hmmm, _maybe_ I get your point. The input capacitors never discharge, so dv/dt is zero. Thus, no inrush peak after startup. Dammit. Didn't need a sine inverter at all..... It's on the bench now, waiting for the battery to arrive. Thanks for posting! bob prohaska> Battery to AC inverters are different. > > > ..... Phil > >
Reply by ●June 29, 20222022-06-29
On Tue, 28 Jun 2022 13:37:59 -0700 (PDT), Phil Allison <pallison49@gmail.com> wrote:>legg wrote: >================ > >** Learn to trim - asshole. > >> >> >Anybody measured the ripple? >> >> Electrolytic life is rms current dependent, among other things (like >> temperature).If you stick one next to a vacuum tube, it's received radiated that dominates part temperature, and voltage stress of the app that dominates.> >** You just made that mad crap up.If you've ever calculated mtbf under Mil Hdbk 217, or Belcore, you'd be aware of dominating life factors.> >Temp is the single determining factor on expected life. >Almost always the local ambient completely dominates.Current forces self-rise due the part's ESR and limited body surface area, (unless you stick it next to a hot radiator). The actual relevant temperature is measured on the component's body.> >> Electrolytics normally have a predicted life some orders of >> magnitude shorter than most other components > >** Then in practice often outlast the lot. > The one exception being vacuum tubes.Given a reliable heater and low vibration, tube life is roughly related to the temperature of the glass envelope. http://ve3ute.ca/2000a.html> > > >..... PhilRL
Reply by ●June 29, 20222022-06-29
