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| tabbypurr@gmail.com: Sep 20 04:39PM -0700 On Friday, 20 September 2019 14:31:05 UTC+1, Phil Allison wrote: > Has advantages in terms of how many units can be run of the same power circuit and is often mandated in regulations for lighting and computer products. > But not for domestic or entertainment audio. > ..... Phil PFC is mandated for domestic goods above 20w here. PFC correction & the ability to run at 120 & 240 without changing a switch are of course 2 separate things. NT |
| Phil Allison <pallison49@gmail.com>: Sep 20 06:49PM -0700 Some Bullshitting Idiot called tabb...@gmail.com wrote: -------------------------------------------------------- > PFC is mandated for domestic goods above 20w here. ** No it isn't. EN 61000-3-2 set some limits on the levels of harmonic current permitted. http://www.epsma.org/PFC%20Guide_November%202010.pdf These limits are sufficiently high that the majority of electronic devices intended for domestic use meet the standard with no special correction circuit or device installed. > PFC correction & the ability to run at 120 & 240 without changing > a switch are of course 2 separate things. ** But are closely related since active PFC allows a designer to fairly easily achieve 85VAC to 265VAC operation and which many items already have. Wide input range SMPS without active PFC exist, but IME are less common. ..... Phil |
| tabbypurr@gmail.com: Sep 21 01:53AM -0700 On Saturday, 21 September 2019 02:49:16 UTC+1, Phil Allison wrote: > EN 61000-3-2 set some limits on the levels of harmonic current permitted. > http://www.epsma.org/PFC%20Guide_November%202010.pdf > These limits are sufficiently high that the majority of electronic devices intended for domestic use meet the standard with no special correction circuit or device installed. Silly me, I thought it was obvious I was referring to devices with poor pf. NT |
| Phil Allison <pallison49@gmail.com>: Sep 21 02:26AM -0700 Some Nut Case Damn LIAR called tabb...@gmail.com wrote: ---------------------------------------------------- > > These limits are sufficiently high that the majority of electronic > > devices intended for domestic use meet the standard with no special > > correction circuit or device installed. ---------------------------------------------------- > Silly me, I thought it was obvious I was referring to devices with poor pf. ** FFS dickwad, the regs do not even mention the term "power factor". Try actually reading them before blowing bullshit out you arse. PFC is in no way "mandated" . .... Phil |
| Rob <nomail@example.com>: Sep 21 10:19AM > Wide input range SMPS without active PFC exist, but IME are less common. Before the PFC solution there were SMPS that used the standard rectifier/doubler setup with a TRIAC in place of the jumper that normally selects 120V/240V operation. |
| tabbypurr@gmail.com: Sep 21 04:22AM -0700 On Saturday, 21 September 2019 10:26:12 UTC+1, Phil Allison wrote: > Try actually reading them before blowing bullshit out you arse. > PFC is in no way "mandated" . > .... Phil Horse. |
| Phil Allison <pallison49@gmail.com>: Sep 21 04:52AM -0700 Rob wrote: ------------- > Before the PFC solution there were SMPS that used the standard > rectifier/doubler setup with a TRIAC in place of the jumper that > normally selects 120V/240V operation. ** Yeah - the cct starts off in the 240V position and jumps down to the 120V setting if the output voltage is much too low. Think makers called it "auto-select" or something like that. Few examples were ever made so I suspect their were some issue with it like when the AC supply was dodgy - ie brown outs and such like. It's safer to have the setting locked to the AC voltage where you live - and not have it jump to voltage doubling cos of a short term voltage drop. The PFC solution normally works brilliantly, long as the AC supply impedance is reasonably low. If there are hundreds of metres of 15amp cable between the load and the supply - all bets are off. Then, if the AC voltage drops, the load draws more current causing the voltage to drop more - and well you get the idea. .... Phil |
| tabbypurr@gmail.com: Sep 21 07:53AM -0700 On Saturday, 21 September 2019 12:53:01 UTC+1, Phil Allison wrote: > The PFC solution normally works brilliantly, long as the AC supply impedance is reasonably low. If there are hundreds of metres of 15amp cable between the load and the supply - all bets are off. > Then, if the AC voltage drops, the load draws more current causing the voltage to drop more - and well you get the idea. > .... Phil Safest is to simply design the psu to output the correct voltage with either 240 or 120 in. It's not a big problem to design an smpsu to cope with that from the get go, so there's no need for any bolt-ons to try to get round an inadequate working range. And that's exactly what most do. NT |
| Jeff Liebermann <jeffl@cruzio.com>: Sep 20 04:49PM -0700 >> temperature compensation via a lookup table. Drift is negligible: >> <https://en.wikipedia.org/wiki/Microelectromechanical_system_oscillator> >Big fun when there is only a slight concentration of helium in the air! Yep, but it wasn't so "slight". The leak was about 120 liters of liquid helium, which expands into 90,000 liters (or 90 cubic meters, or 3,200 cubic feet) of helium gas. A typical MRI machine holds about 1,700 liters of liquid helium: <https://www.usgs.gov/centers/nmic/helium-statistics-and-information> <https://prd-wret.s3-us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/atoms/files/mcs-2019-heliu.pdf> Incidentally, 90 cubic-meters at $7.57/cubic-meter = $681 "iPhones Are Allergic to Helium" <https://www.ifixit.com/News/iphones-are-allergic-to-helium> Notice the size of the chip on the fingernail in the photo: <https://www.sitime.com> -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
| Rob <nomail@example.com>: Sep 21 10:18AM > Incidentally, 90 cubic-meters at $7.57/cubic-meter = $681 > "iPhones Are Allergic to Helium" > <https://www.ifixit.com/News/iphones-are-allergic-to-helium> That was the incident that made this wellknown, but others have tried to replicate it and found it doesn't require nearly that high a concentration! For example, see the youtube movie on the Applied Science channel: https://www.youtube.com/watch?v=vvzWaVvB908 |
| bruce2bowser@gmail.com: Sep 20 04:29PM -0700 "Consider what will most likely happen in the fall, when Apple introduces new operating systems. The company says iPhones that can handle that update will be able to operate in "dark mode." That should cut back on emissions of light and, perhaps, ease eye strain. I'd like to use dark mode but I can't, unless I reach for my wallet. That's because my iPhone 6, and older iPhones, won't be compatible with iOS 13, the forthcoming version of Apple's operating system. Owners of older iPads will be in a similar predicament. And owners of new Apple Watches but older iPhones won't be able to update their watches unless they get a newer phone." New York Times - August 23, 2019 -- https://www.nytimes.com/2019/08/23/business/apple-watch-iphone-casio.html |
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