| bart416 | berndj, bismuth won't melt at room temperature but you can still easily melt it on your kitchen stove | 06:33 |
|---|---|---|
| bart416 | And it's less toxic than lead | 06:34 |
| nathan7 | bart416: 'less toxic than lead' | 08:28 |
| nathan7 | bart416: well that's reassuring | 08:28 |
| bart416 | nathan7, you don't want to rub it along your skin | 08:28 |
| bart416 | Or eat it | 08:29 |
| bart416 | that's about it | 08:29 |
| nathan7 | it's bloody heavy | 08:30 |
| bart416 | Yes | 08:30 |
| Helldesk | "Bismuth has unusually low toxicity for a heavy metal." claims the wikipedia article | 11:11 |
| Helldesk | some isotopes of bismuth have potential use in extremely targeted cancer therapy, and then there's pepto-bismol of course | 11:13 |
| Helldesk | with bismuth subsalicylate as the active ingredient | 11:13 |
| bart416 | wikipedia probably won't even mention its more fun uses | 11:21 |
| lekernel | there's merbromin too :-) | 11:47 |
| lekernel | with mercury and brome, used as antiseptic for minor cuts | 11:48 |
| lekernel | yay | 11:48 |
| bart416 | bismuth also makes for an excellent gamma radiation shield | 11:54 |
| bart416 | (It's on par with lead for that) | 11:54 |
| bart416 | Stupid NDA >_> | 11:55 |
| lekernel | why isn't it used more often for radiation shielding? more expensive than lead? | 12:47 |
| bart416 | It is often used for radiation shielding... | 12:52 |
| bart416 | Its also used as a coolant in reactors | 12:52 |
| bart416 | (due to its low melting point) | 12:52 |
| bart416 | lekernel, uhm ever had a ct? | 12:54 |
| lekernel | ct? | 12:55 |
| bart416 | CT scan | 12:55 |
| lekernel | no | 12:55 |
| bart416 | That's a place where you'll commonly find it lightweight shielding to limit radiation exposure | 12:55 |
| bart416 | Like if they need to take a chest ct they'll often give you a something to shield your neck and belly | 12:56 |
| bart416 | That's a place where you'll find bismuth | 12:56 |
| bart416 | Fits the bill perfectly | 12:56 |
| lekernel | well, I also visited two nuclear reactors and a nuclear shelter, and took apart an old xray machine, all used lead for shielding :) | 12:56 |
| bart416 | Well yeah, lead has better mechanical properties | 12:57 |
| nathan7 | Helldesk: what's all this sub-shit? | 13:52 |
| azonenberg | bart416: i just asssumed they were all lead based lol | 17:36 |
| nathan7 | leading | 18:02 |
| bart416 | azonenberg, they're not | 20:22 |
| bart416 | bismuth has only been in use the past 10 years or so though | 20:22 |
| bart416 | So old equipment is generally still lead based | 20:22 |
| bart416 | bismuth is actually a by product of extracting lead from ores | 20:22 |
| bart416 | So they sort of stacked up a pretty big supply throughout the years | 20:23 |
| azonenberg | lol | 20:24 |
| bart416 | btw, the soviets have been using it a lot longer | 20:27 |
| bart416 | That being said, I'd better shut up about this before 1) I get arrested 2) I get somebody killed due to my BAC being fairly high after a bottle of wine | 20:31 |
| bart416 | azonenberg, do you think it'd be viable to power a small railgun with smd capacitors? | 20:38 |
| azonenberg | bart416: Define small :P | 20:40 |
| bart416 | Imagine rifle size | 20:40 |
| azonenberg | My immediate thought is no | 20:41 |
| azonenberg | none of them are rated for even close to high voltage | 20:41 |
| azonenberg | with decent capacitance | 20:41 |
| bart416 | well, if you use copper tubing it doesn't have to be high voltage though | 20:41 |
| XgF | bart416: copper tubing isn't viable for a 'usable' rail gun | 20:41 |
| bart416 | define usable :P | 20:42 |
| XgF | Projectile travels more than 10cm out of the gun before hitting floor :p | 20:43 |
| bart416 | Nah you get them to go way further than 10 cm actually :P | 20:43 |
| XgF | Also, you'd want some form of injection system so you don't have to accelerate the projectile from a dead stop | 20:43 |
| bart416 | You can't accelerate projectiles from dead stop | 20:43 |
| bart416 | I've built enough railguns before XgF :p | 20:43 |
| bart416 | And copper tubing isn't nearly as bad as you'd think :S | 20:44 |
| bart416 | Obviously solid strips of copper are better | 20:44 |
| XgF | Still, magnetic launchers have efficiency which significantly increases with voltage | 20:44 |
| bart416 | The current is important, not the voltage | 20:44 |
| bart416 | Worst case scenario I put some capacitors in series to raise the voltage rating eh :P | 20:45 |
| XgF | Indeed, but increased voltage -> increased current for a given rail resistance. Increased voltage also -> significantly denser energy packing in the capacitor bank | 20:45 |
| bart416 | that is true | 20:46 |
| bart416 | but that's the reason why you'd be using smd in the first place | 20:46 |
| bart416 | you can densly pack pcbs | 20:46 |
| bart416 | and stack them | 20:46 |
| bart416 | + its far lighter than conventional capacitor banks | 20:46 |
| XgF | True | 20:46 |
| XgF | ...Requires experimentation | 20:46 |
| Action: XgF wishes carbon aerogel capacitors didn't have such high ESRs | 20:48 | |
| bart416 | best weapon we ever built that used magnets was a few motor stators + lab PSUs + leds + light sensors | 20:49 |
| bart416 | We embedded a piece of metal into the wall... | 20:49 |
| bart416 | That was in highschool, heh | 20:49 |
| bart416 | damn was that teacher pissed | 20:49 |
| azonenberg | lol | 20:50 |
| azonenberg | how deep and what kind of wall? | 20:50 |
| XgF | Do transformers count? I'd say that my flyback generator was "most likely to injure" | 20:50 |
| azonenberg | a foot into concrete vs a quarter inch into sheetrock is a big \delta | 20:50 |
| XgF | ...though throwing the PSU transformer at them may be more effective :p | 20:51 |
| bart416 | standard european brick wall | 20:51 |
| bart416 | was in the air gap of the wall | 20:51 |
| XgF | Wow | 20:51 |
| bart416 | rectified 380V 3 phase... | 20:52 |
| XgF | I think its the general rule with magnetic weapons: Unless they're really really big, you may be better of throwing the PSU/caps/whatever at them :p | 20:52 |
| XgF | 380V 3 phase? Odd voltage | 20:52 |
| bart416 | Not really :S | 20:52 |
| bart416 | 380V 3 phase is standard in Europe for machines | 20:53 |
| Action: XgF is used to 415V 3phase | 20:53 | |
| bart416 | Where do you live? | 20:53 |
| XgF | UK | 20:53 |
| bart416 | Yeah but UK has always been using its own system | 20:54 |
| XgF | Aah... former 220V country? 400 would be European harmonised, 415 UK norm, 380 norm for a former 220 country | 20:54 |
| bart416 | I've never found 400V RMS on a 3 phase outlet XgF | 20:55 |
| bart416 | Always 380-390V | 20:55 |
| bart416 | 1 phase it's 220-240V | 20:56 |
| XgF | Everythings slightly crazy over here at the moment... all of our distribution equipment has stickers on it warning you that inside you'll find two sets of wiring colours | 20:56 |
| bart416 | :S | 20:56 |
| XgF | Old stuff to the old UK standard; new stuff to EU harmonised standard | 20:56 |
| bart416 | Here we just slap together what we find of wires except in the fuse box | 20:56 |
| bart416 | Cause they actually bother to check that | 20:56 |
| bart416 | heh | 20:56 |
| bart416 | Everything else, meh just pick what you want | 20:56 |
| XgF | Requires some care; old neutral (black) is now a phase colour | 20:57 |
| bart416 | though yellow-green for earth | 20:57 |
| bart416 | black is still used for neutral here as far as I know :S | 20:57 |
| bart416 | Sometimes blue | 20:57 |
| XgF | At least new neutral is light blue as opposed to old phase plain blue | 20:57 |
| bart416 | Phases are usually red-ish tints | 20:58 |
| bart416 | Red, Brown, Orange, ... | 20:58 |
| bart416 | Seen yellow as well a few times in older machines | 20:58 |
| XgF | Still, if you talk about phases around here, we still think in the old (Red, Yellow, Blue) colours. We care because blue is atatched to the fire alarm system | 20:58 |
| bart416 | huh? | 20:59 |
| XgF | Fire alarm goes off -> Blue phase goes off -> PA system goes off -> people can hear the fire alarm | 20:59 |
| XgF | Also, audio stuff tends to get... noisy... if you put it on the same phase as, say, 6 3kW strobes :P | 21:00 |
| bart416 | lol | 21:00 |
| bart416 | Almost as bad as when we make that CNC lathe at a friend's machine shop spin up to speed >_> | 21:01 |
| bart416 | You can see the lights dim, lol | 21:01 |
| XgF | All audio gear goes on blue phase firstly as a anti-noise precaution, secondly because any audio gear which makes noise must go off in event of a fire | 21:01 |
| XgF | ...metal bands are notorious for ridiculously loud guitar cabs | 21:02 |
| bart416 | Talking about metal bands | 21:02 |
| bart416 | Graspop (large metal festival) few years ago | 21:02 |
| bart416 | It's a few kilometers away from a nuclear powerplant eh | 21:03 |
| bart416 | They had no power :') | 21:03 |
| bart416 | Electricity fell out | 21:03 |
| XgF | lol | 21:03 |
| XgF | Festivals tend to run on gen sets | 21:03 |
| bart416 | If you turned your head 10° you could see the reactor dome in the background >_> | 21:03 |
| bart416 | I doubt they were running on generators that close to a powerplant | 21:03 |
| XgF | Tends to be hard to get ~400A 3-Phase supplies installed into the middle of a field | 21:03 |
| XgF | Hiring out a genset works out cheaper | 21:04 |
| bart416 | Nah, the festival is always on the same spot and has been there for so long that they ensured that they can tap off the grid actually | 21:04 |
| bart416 | A lot of heavy industry nearby so not much of an issue I guess | 21:04 |
| XgF | 'fair enough. I just know that even Glastonbury here runs off gen sets | 21:05 |
| bart416 | They had a nice row of fences to prevent people from walking to the transformers actually >_> | 21:05 |
| bart416 | Nice thick 380V power cords, a lot of them | 21:05 |
| bart416 | Was pretty freaky actually | 21:05 |
| bart416 | the camping did run of generators though I think | 21:06 |
| XgF | Probably a set of 5 camlocks per feed :) | 21:06 |
| XgF | powerlocks** | 21:06 |
| bart416 | But it's sort of sad if you tap power of the grid | 21:07 |
| bart416 | You can see the reactor in the background | 21:07 |
| bart416 | And you have no power | 21:07 |
| bart416 | It's really just :') | 21:07 |
| bart416 | It's priceless actually | 21:07 |
| bart416 | But yeah where were we | 21:08 |
| XgF | In the past we've had people get confused because a few of our trips have a time delay before they can be closed again... | 21:08 |
| bart416 | Rectified 380V 3 phase makes for an excellent powersource for magnetic weapons | 21:08 |
| XgF | I can imagine. Unfortunately, I don't think I'd get permission to plug into one of our 125A sockets :p | 21:09 |
| bart416 | lol | 21:09 |
| bart416 | Can't remember how much the current limitation was | 21:10 |
| bart416 | Was pretty high | 21:10 |
| XgF | ...I think they've brought us up to 5 125A sockets in one of our buildings now (+1 125A breakered at 100A) | 21:10 |
| bart416 | :D | 21:11 |
| XgF | I don't know if theres actually capacity to run all of them at once or not, however :p | 21:11 |
| bart416 | Well yeah, the highschool had a pretty nice machine park so they actually needed the ability to draw full power on their 3 phase outlets | 21:12 |
| bart416 | But now I'd just love to try out some of these things in the motor lab at college now | 21:12 |
| bart416 | They tap directly of the high voltage grid | 21:12 |
| bart416 | And have their own transformer as far as I know | 21:12 |
| XgF | It's an octagon shaped room... which means that various events want to run in random corners of it | 21:13 |
| bart416 | lol | 21:13 |
| bart416 | why octagon? :S | 21:13 |
| XgF | Dunno. maybe they decided upon the name "The Octagon Center" and then thought it would be a good shape :p | 21:13 |
| XgF | So practically you're never going to use more than 3 of the sockets (+ the 100A one, since that feeds the dimmer pack) | 21:13 |
| bart416 | :D | 21:16 |
| bart416 | yay, only 4 more rar files to go and I'll have all elektor things from 1980 till 2010 | 21:17 |
| XgF | RAR is a damned inconvinient archive format | 21:18 |
| azonenberg | indeed | 21:18 |
| XgF | Whenever I need to open one, I never have software to do so | 21:18 |
| bart416 | I have winrar installed on all my computers so not much of an issue | 21:20 |
| XgF | Installing WinRAR on my Macbook would prove challenging | 21:20 |
| bart416 | You deserve to get shot for using a mac anyway | 21:20 |
| bart416 | Crappy expensive laptops | 21:21 |
| azonenberg | lol indeed | 21:21 |
| XgF | When I sell it in a couple of years, I'll get back the extra I paid for it, and if anything breaks, I can walk into an Apple store and have them fix it for me that day :p | 21:21 |
| bart416 | In college last year "how do I get eagle to work on my macbook????" :| | 21:21 |
| azonenberg | Or you could use a sawzall | 21:21 |
| XgF | Install it | 21:22 |
| bart416 | "how do I get this cisco vpn client to work on my macbook?" | 21:22 |
| azonenberg | Never fails to remove the offending mac from your life | 21:22 |
| bart416 | "how do I get ... to work on my macbook?" | 21:22 |
| bart416 | XgF, do like me | 21:22 |
| XgF | Serves all the roles in my life Linux used to... without every other package coming broken | 21:22 |
| bart416 | buy a thinkpad | 21:22 |
| azonenberg | bart416: sudo apt-get install c4-explosive; sudo c4-explosive --detonate | 21:22 |
| bart416 | lol | 21:22 |
| azonenberg | from a livecd on the mac | 21:22 |
| bart416 | azonenberg, detonator not found | 21:22 |
| azonenberg | ah, i remember now | 21:23 |
| bart416 | dpkg-reconfigure c4-explosive --install-detonator | 21:23 |
| XgF | (...does Bluetooth work on Linux yet? I mean, I had a generic Bluetooth USB dongle and it refused to work) | 21:23 |
| azonenberg | c4-blastingcap i think is the package | 21:23 |
| bart416 | But really thinkpads are the best laptops I've ever used | 21:23 |
| azonenberg | it's listed in the recommended packages but isnt installed by default for safety reasons :p | 21:23 |
| bart416 | almost impossible to destroy | 21:23 |
| bart416 | fast | 21:23 |
| bart416 | great hardware support | 21:23 |
| bart416 | almost no pre installed crap | 21:23 |
| XgF | Nah. Like every PC laptop, their trackpads are a peice of shit sent from hell | 21:23 |
| bart416 | and matte screen! | 21:23 |
| bart416 | Yeah but thinkpads have the red dot as mouse :P | 21:24 |
| XgF | That is a flaming peice of shit sent from hell :p | 21:24 |
| bart416 | Nah, its awesome | 21:24 |
| bart416 | It's for when you're jumping out of an airplane and can't operate the touchpad easily | 21:24 |
| XgF | All laptops should come with multitouch trackpads a standard | 21:24 |
| bart416 | You can use the red dot | 21:24 |
| bart416 | The thinkpad doesn't need a parachute btw | 21:25 |
| bart416 | It has a built in set of rockets to slow down when it nears the ground | 21:25 |
| bart416 | Together with an auto deploying airbag | 21:25 |
| bart416 | Or something like that | 21:25 |
| bart416 | I've seen a thinkpad drop from the astronomy club tower (4 floors high) | 21:26 |
| bart416 | onto pretty hard ground | 21:26 |
| bart416 | All it said was "powercord unplugged" | 21:26 |
| bart416 | xD | 21:26 |
| XgF | My general line of thought was "I need a laptop. It must be Unixy. Linux requires too much fucking around. Every other Unix requires at least as much fucking around as Linux. This leaves me with only one option" | 21:26 |
| bart416 | Nah on thinkpads it works smoothly | 21:27 |
| XgF | Linux doesn't work smootly (enough) on anything | 21:27 |
| bart416 | On thinkpads it does | 21:27 |
| bart416 | Never needed to install any driver | 21:27 |
| bart416 | Everything I needed came with the standard debian dvds | 21:28 |
| XgF | If I plug in my phone, it should automatically configure it to work as a cellular modem. If I plug in a Bluetooth dongle, it should enable Bluetooth. | 21:28 |
| bart416 | that's peripherals though | 21:28 |
| bart416 | That's another subject | 21:28 |
| XgF | ...The Bluetooth dongle should work simply, damnit. There is one standard which every USB dongle supports | 21:29 |
| bart416 | not really | 21:29 |
| bart416 | I've never ever seen any usb device stick to a standard completely | 21:29 |
| bart416 | Not even damned usb drives can get it right at times | 21:29 |
| XgF | Right, but they're all pretty close | 21:30 |
| bart416 | http://be.farnell.com/avx/w3a41c102mat2a/capacitor-array-1000pf-100v-x7r/dp/1582629 | 21:32 |
| bart416 | ^how about those capacitors | 21:32 |
| XgF | 1nF... not gonna get much energy into them unless in ridiculous bulk | 21:33 |
| azonenberg | Lol yeah | 21:36 |
| azonenberg | you need a few hundred uf | 21:36 |
| azonenberg | at least | 21:36 |
| XgF | I can't get to Farnell BE from here... but I would say that even if you can afford the hundreds of thousands required, they'd probably end up more bulky | 21:37 |
| bart416 | well yeah, I'm not looking at going in excess of 200 m/s for this :P | 21:37 |
| bart416 | also, wrong link | 21:38 |
| bart416 | capacitors I'm looking at are 1uF 100V | 21:39 |
| bart416 | still not really sufficient in my opinion | 21:39 |
| XgF | Quick calculations say 20J/g for 200m/s | 21:39 |
| XgF | (of course assuming 100% efficiency. unlikely) | 21:39 |
| azonenberg | Yeah lol | 21:39 |
| azonenberg | 20 kJ is more like what you should be trying for | 21:39 |
| azonenberg | for a couple of grams to a few hundred m/s | 21:40 |
| bart416 | I'd need roughly 4 farad for that though | 21:41 |
| azonenberg | bart416: no, you need higher voltage :P | 21:41 |
| azonenberg | a few hundred uf at 4 kV | 21:41 |
| bart416 | at 4kV you'd still need 2.5 mF ;) | 21:41 |
| azonenberg | Soudns about right | 21:42 |
| azonenberg | 6x 350 uf? | 21:42 |
| XgF | So we're talking something ~50BMG sized :p | 21:42 |
| azonenberg | thats what the electronics club at my school had in their HV cap bank | 21:42 |
| azonenberg | XgF: This cap bank was laser discharge caps | 21:42 |
| bart416 | I already have a large high voltage capacitor bank | 21:42 |
| bart416 | I want a smd version though | 21:42 |
| azonenberg | 2-inch high ceramic insulators on top | 21:42 |
| azonenberg | the things weighed 75 pounds each | 21:43 |
| azonenberg | but could discharge in microseconds | 21:43 |
| bart416 | That's also why smd | 21:43 |
| bart416 | smd capacitors are more ideal | 21:43 |
| azonenberg | And how much current do you plan to run through these tiny little 30 micron thick traces? :P | 21:45 |
| XgF | I've heard that some of the bigger rail guns use flywheels | 21:45 |
| bart416 | http://be.farnell.com/murata/decb33j681kc4b/capacitor-ceramic-680pf-6-3kv/dp/1401978 | 21:45 |
| bart416 | azonenberg, that's the beauty of the thing, you only need the traces until you reach the connectors | 21:45 |
| bart416 | + it's short duration so the copper can handle it | 21:46 |
| bart416 | 6.3kV... | 21:46 |
| XgF | + do like PSU manufacturers and solder some copper along the length of the trace | 21:46 |
| azonenberg | 600 pf though | 21:46 |
| bart416 | yeah that's not so ideal | 21:46 |
| XgF | 0.013 J/cap | 21:47 |
| azonenberg | http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=490-3505-1-ND | 21:47 |
| azonenberg | 100nf / 1kV | 21:48 |
| bart416 | I'd rather order from farnell azonenberg :P | 21:48 |
| bart416 | I can order from farnell through college | 21:48 |
| bart416 | no shipping fees, no taxes | 21:48 |
| azonenberg | Find the part first | 21:48 |
| azonenberg | then figure out where to get it | 21:48 |
| XgF | .05/cap | 21:48 |
| bart416 | also, price needs to be reasonable eh | 21:50 |
| bart416 | I'm not going to pay €1 / capacitor | 21:50 |
| bart416 | http://be.farnell.com/avx/ffli6u0867k/capacitor-pp-film-pp-860uf-1-15kv/dp/1867545 | 21:59 |
| bart416 | two of those would do | 21:59 |
| bart416 | lol | 21:59 |
| bart416 | for a small railgun | 21:59 |
| azonenberg | kinda pricey? | 21:59 |
| bart416 | and it only weights ~5kg in total >_> | 21:59 |
| bart416 | yeah exactly | 21:59 |
| bart416 | meh screw this | 22:09 |
| bart416 | How hard can it possibly be to make your own ceramic capacitors? :P | 22:10 |
| azonenberg | Easy | 22:11 |
| azonenberg | Making them work as well as commercial ones? Hard | 22:11 |
| bart416 | yeah that's the thing | 22:13 |
| bart416 | I know how to make tantalum capacitors actually | 22:14 |
| bart416 | The process isn't that hard | 22:14 |
| bart416 | But the equipment is horribly expensive | 22:14 |
| bart416 | Need a vacuum furnance capable of doing roughly 1500°C | 22:14 |
| XgF | Also, commercial tantalums are prone enough to deciding they'd rather be on fire | 22:14 |
| lekernel | 475,94¬ for 860uF at 1.5kV? | 22:14 |
| lekernel | better use a combination of electrolytics from disposable cameras :-) | 22:14 |
| bart416 | lol XgF | 22:15 |
| bart416 | If it's on fire you can lob at the thing you're shooting at :P | 22:16 |
| bart416 | electrolytics are horrible for railguns though lekernel | 22:16 |
| azonenberg | bart416: sputtered / evaporated aluminum | 22:17 |
| azonenberg | then PECVD SiO2 | 22:18 |
| azonenberg | then more aluminum :P | 22:18 |
| azonenberg | Actually, not SiO2 - use a high-K material | 22:18 |
| azonenberg | maybe sputtered Ta2O5 | 22:18 |
| bart416 | http://be.farnell.com/nichicon/juwt1105mcd/capacitor-dbl-layer-1f-2-7v-rad/dp/1894491 | 22:21 |
| bart416 | mhhh | 22:21 |
| bart416 | azonenberg, copper plates with titanium dioxide as dielectric | 22:30 |
| berndj | XgF, i find the blue/brown scheme totally crazy compared to red/black | 22:40 |
| berndj | it's like going from 100% intuitive to 30% confusing | 22:40 |
| XgF | berndj: It is colour blind safe | 22:40 |
| berndj | compare blue from single-phase wiring with blue from 3-phase wiring - see a blue wire... which is it! | 22:40 |
| XgF | Same | 22:41 |
| XgF | Blue is always neutral | 22:41 |
| XgF | Brown, Black, Gray (IIRC) are phase | 22:41 |
| berndj | blue is always neutral except when the other wire is brown | 22:44 |
| XgF | Wha? EU harmomisation says blue is always neutral | 22:45 |
| berndj | oh, i guess black is another one then: new 3-phase phase wire or old neutral? | 22:46 |
| berndj | er, i misspoke. blue is always neutral except when the other wires are red and yellow | 22:46 |
| XgF | Well, if you see "Red, yellow, blue, black" you have old standard; "brown, black, grey, light blue" you have new harmonised standard | 22:47 |
| azonenberg | And in the USA black i think is usually hot :P | 22:47 |
| azonenberg | white neutral and green ground | 22:47 |
| azonenberg | (in single phase wiring) | 22:47 |
| XgF | Yes | 22:48 |
| berndj | dunno, but i find the old colours a million times less confusing; granted, i'm not colour-blind, that's a valid argument | 22:48 |
| berndj | yeah, at least green/yellow is universally earth! | 22:48 |
| Action: XgF wonders when ring mains are going to be dropped from the regs | 22:49 | |
| berndj | our appliances are all brown/blue but afaik house wiring is still red/black | 22:50 |
| XgF | They're obsolete | 22:50 |
| XgF | The UK only changed install wiring a few years ago | 22:50 |
| berndj | i think brown/blue house wiring is _allowed_ but not required | 22:50 |
| berndj | damn those europeans and their funny colours! | 22:51 |
| XgF | Also, people seem to like installing ring mains even when a radial would be cheaper. like our kitchen fitter | 22:51 |
| berndj | i was under the impression ring mains were actually _required_ in the uk? | 22:51 |
| XgF | Both sides of the ring run *taped together* behind all our kitchen units. It would have been cheaper to buy one 32A cable | 22:51 |
| berndj | perhaps with emphasis on "were" - past tense | 22:52 |
| XgF | Never required | 22:52 |
| berndj | here ring mains are quasi-strictly verboten | 22:52 |
| XgF | Presumably radials fused at >16A are too? | 22:53 |
| XgF | being as your plugs aren't fused | 22:53 |
| berndj | nope; you're allowed to have up to 20A with socket outlets rated at 17A | 22:53 |
| XgF | OK, up to 20A | 22:53 |
| berndj | our plugs aren't fused, but GFCI has been mandatory for decades | 22:54 |
| XgF | same here | 22:54 |
| XgF | Here I think up to 32A is allowed to sockets | 22:54 |
| berndj | 32A... wow | 22:54 |
| berndj | oh, but your plugs are fused | 22:54 |
| XgF | If memory serves me... some engineers carry 125A three phase to 230V british standard plug adaptors to plug their kettle into :p | 22:55 |
| XgF | Not sure on the exact legality of that without intervening circuit breakers | 22:55 |
| azonenberg | In my living room here in the USA we have three 20A circuits | 22:55 |
| berndj | lol @ 125A. my house breaker is only 60A | 22:55 |
| bart416 | On 110V I guess azonenberg ? | 22:55 |
| azonenberg | each one has somewhere between 2 and 4 plates, each with 2x 15A outlets | 22:55 |
| azonenberg | Yes | 22:56 |
| bart416 | Urgh :| | 22:56 |
| XgF | berndj: 125A *three phase*. 375A of single phase power :D | 22:56 |
| bart416 | Sounds like a damned fire hazard to me :P | 22:56 |
| XgF | Our downstairs, upstairs and kitcheneach have a 32A ring | 22:56 |
| azonenberg | bart416: I spread the load around | 22:56 |
| azonenberg | my server farm is plugged into two or three plates | 22:56 |
| azonenberg | pulling close to 20A in total | 22:56 |
| azonenberg | But i dont think there is anything stopping you from pulling 15 < x < 20 without blowing | 22:57 |
| azonenberg | from one outlet | 22:57 |
| berndj | afaik breakers' rating have 33% slop | 22:57 |
| berndj | so if it says 20A, it's allowed to trip only at up to 26A | 22:58 |
| berndj | err, that's weirdly phrased, hope you guys can parse that | 22:58 |
| XgF | 33% rating slop, plus something like +20% for 1 hour or less, on a logarithmic increasing scale (+10% for 2 hours and so on) | 22:58 |
| berndj | and momentary draws way in excess are no problem; 5x overcurrent for even the fastest breakers | 22:59 |
| berndj | i'm still trying to find info on whether "curve 1", "curve 2" etc. are actual standards or just loose manufacturer consensi | 23:00 |
| bart416 | Our 380V in the house has 38A breakers | 23:00 |
| bart416 | For outside I think it was somewhere around 60A | 23:01 |
| bart416 | (outside including toolshed etc...) | 23:01 |
| bart416 | Regular 230V has 16A breakers | 23:01 |
| XgF | I think the Student Union building I work in has a 2kA 3phase supply or something equally ridiculous | 23:01 |
| berndj | my PSCC isn't even 2kA | 23:02 |
| XgF | (Yes, it has its own mini substation) | 23:02 |
| berndj | kettle+multimeter+calculator says it's only about 460A :( | 23:02 |
| bart416 | lol | 23:02 |
| XgF | But we are talking about a building with something like 9 eateries in it, so it does use a lot of power for cookers and such :p | 23:03 |
| berndj | there's probably something wrong with the supply, i can't believe that the PSCC should be that low | 23:03 |
| bart416 | XgF, you should see the distribution boxes in some machine shops | 23:03 |
| bart416 | It's nuts | 23:03 |
| azonenberg | bart416: My school has at least two major transformer substations | 23:04 |
| bart416 | the manual circuit breakers are just big copper bars with a long handle cause they're certain they'll arc xD | 23:04 |
| azonenberg | But the union doesnt have one ofi ts own | 23:04 |
| bart416 | azonenberg, I know of 3 | 23:04 |
| azonenberg | Well, one of these two is huge | 23:05 |
| bart416 | 2 for the mechanical and electrical engineering building | 23:05 |
| bart416 | And 1 for the textile engineering building | 23:05 |
| azonenberg | like, multiple 40kV lines running in | 23:05 |
| XgF | Theres another one under the Octagon Center, I think similar current supply. My building (physics department) probably has one. Engineering buildings probably have one each | 23:05 |
| azonenberg | to a few dozen transformers | 23:05 |
| XgF | Being as we are in the middle of a city, they're all underground | 23:05 |
| azonenberg | These two are aboveground | 23:05 |
| bart416 | Lab I worked in a few years ago was even more insane | 23:05 |
| azonenberg | There is at least one more underground in the engineering building basement | 23:06 |
| bart416 | But yeah, that was to feed that damned synchrotron >_> | 23:06 |
| bart416 | The entire basement was filled with equipment for power management | 23:06 |
| bart416 | If I would have stolen one of those transformers in some way I would be rich simply cause of the scrap iron I think | 23:07 |
| bart416 | Let alone the copper >_> | 23:07 |
| azonenberg | Lol | 23:07 |
| XgF | bart416: You'd probably lose it all again to oil disposal | 23:07 |
| bart416 | You can sell the oil as well XgF | 23:07 |
| azonenberg | XgF: If you're stealing equipment you probably dont care about the environment | 23:07 |
| azonenberg | Sewer | 23:08 |
| bart416 | That too | 23:08 |
| XgF | azonenberg: depends on how sure you are that the transformer isn't full of something potentially nasty to you :p | 23:08 |
| bart416 | XgF,EU regulations won't allow that :P | 23:09 |
| bart416 | it's always some sort of synthetic oil that just smells bad | 23:09 |
| azonenberg | XgF: Again, If you're pulling gear out of a live circuit | 23:09 |
| XgF | bart416: Depends on the xformer's age | 23:09 |
| bart416 | Except in older transformers | 23:09 |
| azonenberg | I dont think you're that too concerned | 23:09 |
| bart416 | That drains into the skin actually | 23:09 |
| bart416 | but is non toxic | 23:09 |
| bart416 | Just wear gloves | 23:10 |
| XgF | azonenberg: I might know how to kill power to the transformer. I might not know whether it contains something like PCBs | 23:10 |
| azonenberg | True | 23:10 |
| azonenberg | You'll find out in 20 years? :P | 23:10 |
| XgF | We have enough cupboards sealed off with asbestos stickers for me to worry about :p | 23:11 |
| bart416 | azonenberg, very few transformers use toxic oil | 23:11 |
| XgF | bart416: Depends upon age, of course. Pre ~1980... | 23:12 |
| bart416 | And honnestly in this case I'd be more worried about the device the transformer in question is powering than the transformer itself, heh | 23:12 |
| XgF | true | 23:12 |
| berndj | http://www.bpj-code.co.za/images/ht-fuse.jpeg <-- in case a nail can't handle enough current | 23:13 |
| bart416 | Who can download the full 400 mb of this file: http://fileserve.com/file/uevBtbr | 23:16 |
| bart416 | Most I've been able to get is 120 mb | 23:16 |
| berndj | what, you want to steal a cyclotron too now in addition to the transformer? | 23:16 |
| bart416 | Why not :P | 23:17 |
| bart416 | You'll have to break open the damned building anyway to steal the transformer | 23:17 |
| bart416 | You can as well steal a particle accelerator while you're at it | 23:17 |
| bart416 | Even if it's a small one | 23:17 |
| smeding | berndj: is that an x100e? :p | 23:17 |
| smeding | behind the fuse, i mean | 23:18 |
| berndj | behind the fuse is the laptop i'm ircing on right now | 23:18 |
| berndj | it's a lenovo something or other | 23:18 |
| smeding | it looks like an x100e, or at least a recent smaller lenovo laptop | 23:18 |
| berndj | something something 560 springs to mind | 23:19 |
| smeding | i have an x100e - i love the damn thing to death | 23:19 |
| berndj | any ballpark guess for how much current my fuse can take? | 23:21 |
| berndj | the printed rating, if there ever was one, has faded into nothingness | 23:22 |
| bart416 | test it? :P | 23:26 |
| berndj | send PSU pls | 23:27 |
| berndj | from the size alone i have to guess at least a few hundred amp | 23:27 |
| azonenberg | http://www.emsdiasum.com/microscopy/technical/techtips/mounting_specimens.aspx | 23:31 |
| azonenberg | very interesting | 23:31 |
| azonenberg | i may have to try this | 23:31 |
| azonenberg | i need something to embed samples in for cross sectioning | 23:32 |
| azonenberg | first, for optical microscopy | 23:33 |
| bart416 | You should just use duct tape | 23:38 |
| --- Sun Aug 21 2011 | 00:00 | |
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