highaltitude.log.20090309

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[00:19] <Laurenceb> hmm certainly better performance
[00:20] <Laurenceb> not sure how well suited mfsk is to this technique
[00:20] <Laurenceb> and soundcards suck
[00:29] <Laurenceb> hmmm http://www.avrfreaks.net/index.php?module=Freaks%20Academy&func=viewItem&item_id=1855&item_type=project
[00:29] <Laurenceb> jihad mmc recorder?
[00:29] <gordonjcp> hmm, you need to be logged in for that
[00:29] <gordonjcp> ftn
[00:35] <Laurenceb> ok basically its along the line of "IN THE NAME OF GOD... this is our mmc recorder.... ALLAH AKBAR"
[00:35] <Laurenceb> didnt know osama was into avrs
[00:36] <Laurenceb> I should use that as a greeting IN THE NAME OF GOD hello and good afternoon sir
[01:00] Action: shellevil greets Laurenceb in the name of the flying spaghetti monster, hallowed be his noodly name.
[01:02] Action: Laurenceb kills infidels to get his 72 pot noodles in heaven
[02:28] <natrium42> lol
[02:32] <shellevil> Unopened pot-noodles, with the seal on!
[02:33] <natrium42> whoa!
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[09:31] <jcoxon_> morning all
[09:31] <jcoxon_> oops i'm still logged on at home
[09:36] <shellevil> morning
[09:36] Action: shellevil goes back to sleep
[09:36] <shellevil> was lifting floorboards yesterday
[09:39] <jcoxon_> morning shellevil
[09:40] <hallam> hello
[09:40] Action: hallam has the noro, woo
[09:41] <jcoxon_> hey hallam
[09:41] <jcoxon_> urgh, this noro is crazy
[09:41] Action: jcoxon_ prescribes fluids
[09:42] <jcoxon_> (though i'm not allowed to prescribe yet)
[09:42] <hallam> tut tut
[09:42] <hallam> being able to prescribe must be so much fun
[09:42] <jcoxon_> i read somewhere that peopole with noro can infect on average 14 other people
[09:42] <hallam> I'd never pass the ethics part
[09:43] <jcoxon_> perscribing is really difficult as you have to get it right and remember loads about the drugs, dosages and interactions - not looking forward to that
[09:44] <hallam> do you get to prescribe hugs and stuff like that?
[09:44] <jcoxon_> if its in the bnf i will be able to prescribe it
[09:44] <jcoxon_> i don't think hugs are
[09:45] <hallam> disappointing
[09:45] <hallam> the nurse recommended tomato soup, but all I have is mushroom
[09:45] <jcoxon_> nope its not there
[09:45] <hallam> will it make me explode?
[09:46] <jcoxon_> nah
[09:46] <jcoxon_> mushroom will be fine
[09:46] <hallam> ok I'll go make some then
[09:46] <hallam> thanks
[09:46] <jcoxon_> don't eat too much though - little and often
[10:09] <jcoxon_> hallam: http://www.copenhagensuborbitals.com/
[10:17] <hallam> it's cool - I've heard some weird things about the people behind it, but I wish them luck
[10:17] <hallam> I think I will try to doze some more
[10:17] Nick change: hallam -> hallam|away
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[11:54] <edmoore> morning all
[11:54] <edmoore> still, just about
[11:55] <SpeedEvil> indeed.
[11:55] Action: SpeedEvil has taken a break from lifting floorboards.
[11:57] <edmoore> quite right too
[11:57] <edmoore> what is under them?
[11:58] <SpeedEvil> sand, with tar over it
[11:59] <SpeedEvil> I intend to place insulation there.
[12:12] <natrium42> best floor for a lab is tiles
[12:13] <natrium42> easiest to clean
[12:14] <natrium42> lol :( --> http://valleywag.gawker.com/5166216/martha-prepares-loses-chow-prepares-chow
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[12:54] <hallam|away> wonders of ebay: http://cgi.ebay.com/Webkinz-Plumpy-Charm-CODE-AND-CERTIFICATE-ONLY_W0QQitemZ270355032385QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item270355032385&_trksid=p3286.c0.m14&_trkparms=72%3A1205|66%3A2|65%3A12|39%3A1|240%3A1318|301%3A0|293%3A1|294%3A50
[13:00] <SpeedEvil> 'plumpy charm'
[13:01] <SpeedEvil> I was thinking that might be an entirely different sort of website.
[13:03] <SpeedEvil> http://www.mauve.plus.com/pict0215.jpg
[13:03] <SpeedEvil> My workroom floor ATM
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[13:29] <mc-> hi jcoxon, I'm on IRC on the train, trying to keep up with you...
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[16:28] <Laurenceb> yello
[16:29] <shellevil> purple
[16:30] <shellevil> http://www.mauve.plus.com/pict0215.jpg floor ATM
[16:30] <Laurenceb> interesting
[16:30] <Laurenceb> whats underneath?
[16:30] <Laurenceb> sand?
[16:30] <shellevil> sand+tar
[16:30] <Laurenceb> dry rot :-S
[16:30] <shellevil> none
[16:31] <Laurenceb> odd
[16:31] <Laurenceb> looks like a recepie for dry rot
[16:31] <shellevil> the sand is quite dry
[16:31] <Laurenceb> is it on a dpm?
[16:31] <shellevil> there are little dwarf walls across it
[16:31] <Laurenceb> ah ok
[16:31] <Laurenceb> I thought those were wood
[16:32] <shellevil> with tar on top of them, on which the floorboard joists sit
[16:32] <Laurenceb> cool makes sense
[16:32] <shellevil> getting the joists filled up with insulation, with a mesh below.
[16:32] <shellevil> and then vapour barrier up top
[16:33] <Laurenceb> the floor I was working on over the summer is gravel,sand, dpm, reinforced concrete, bitumen, then tiles
[16:33] <shellevil> ordered new boards
[16:33] <Laurenceb> took a while to build :P
[16:33] <Laurenceb> cool
[16:33] <shellevil> for this room, then use the old ones as spares for the rest
[16:34] <Laurenceb> yeah with wood floors you can insulate
[16:34] <shellevil> and the wall on the left of that needs insulated, as does round the window
[16:35] <shellevil> Tidying up to get teh room cclean must have taken 50* longer than doing the floor
[16:36] <Laurenceb> and upstairs floors to do?
[16:36] <shellevil> no upstairs
[16:36] <Laurenceb> ah ok
[16:36] <shellevil> ~1700 linen weavers cottage
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[16:37] <Laurenceb> specialised for linen weaving?
[16:39] <shellevil> not really
[16:44] <Laurenceb> http://www.anti-christ.com/?p=25
[16:44] <Laurenceb> ^ lulz
[16:56] <Laurenceb> http://wiki.ukhas.org.uk/code:ground_data
[17:03] <Laurenceb> pCharts works very nicely :P
[17:09] <shellevil> :)
[17:09] <Laurenceb> this is interesting -> http://files.asme.org/asmeorg/Communities/History/Landmarks/12708.pdf
[17:12] <shellevil> fun
[17:35] <jcoxon> evening all
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[18:41] <jcoxon> anyone around?
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[18:52] <jcoxon> hey edmoore
[18:53] <edmoore> hi jcoxon
[18:53] <edmoore> all well?
[18:54] <jcoxon> yeah
[18:54] <jcoxon> you?
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[19:00] <Laurenceb> hello
[19:01] <Laurenceb> mc-: hi
[19:01] <mc-> hi lb
[19:01] <Laurenceb> mc-: do you have a 434MHz ant?
[19:01] <mc-> hows MFSK going? yes, I have a 433 ant
[19:01] <Laurenceb> was thinking of trying a range test
[19:01] <Laurenceb> yeah seems to be working
[19:01] <mc-> you can use a piece of wire 16cm long
[19:02] <Laurenceb> he
[19:02] <mc-> or I have a yagi somewhere
[19:02] <Laurenceb> yeah I've got an ant at my end
[19:02] <Laurenceb> do you have a receiver setup?
[19:02] <jcoxon> Laurenceb, where abouts are you?
[19:02] <Laurenceb> guildford
[19:03] <mc-> what sort of receiver? I only have a cheap module receiver
[19:03] <Laurenceb> ah ok
[19:03] <Laurenceb> youd need ssb
[19:03] <mc-> do you have a ssb receiver?
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[19:03] <Laurenceb> yep
[19:04] <Laurenceb> icom pcr-1000
[19:04] <mc-> nice
[19:04] <mc-> I could take your transmitter for a test drive
[19:04] <Laurenceb> nvm I'm sure it works
[19:04] <Laurenceb> yeah your welcome to borrow it
[19:05] <Laurenceb> oh tx
[19:05] <Laurenceb> its ok thanks I'm pretty sure it works
[19:05] <jcoxon> Laurenceb, i'm 28 mile away
[19:05] <jcoxon> miles*
[19:05] <Laurenceb> hmm
[19:05] <jcoxon> probably a little far
[19:05] <mc-> do you have line of sight to the south?
[19:05] <Laurenceb> if I stick it out of the window I doubt its going to reach
[19:06] <Laurenceb> I could head outside somewhere but cant be bothered to walk up a hill at this time
[19:06] <Laurenceb> mc-: nope
[19:06] <jcoxon> i can face SW
[19:06] <Laurenceb> theres the cathedral in the way
[19:07] <Laurenceb> jcoxon: do you have much interference?
[19:07] <mc-> I'm on the train at the moment
[19:07] <jcoxon> ummmm so so
[19:07] <Laurenceb> mc-: 3G?
[19:08] <mc-> train has free wifi
[19:08] <edmoore> which one!?!?!
[19:08] <mc-> national express train from leeds to london
[19:09] <Laurenceb> sweet
[19:09] <mc-> it's painfully slow, but perfect for IRC
[19:09] <Laurenceb> national express?
[19:09] <Laurenceb> thought they ran busses
[19:11] <Laurenceb> http://www.adaptivemodules.co.uk/index.cfm/fa/shopdetails/Product_ID/318/Category_ID/12
[19:11] <Laurenceb> still think thats the way to go
[19:11] <edmoore> bbl
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[19:22] <mc-> jcoxon, do you have a name for your transatlantic mission?
[19:22] <jcoxon> Atlantic Halo
[19:23] <jcoxon> http://spacenear.us/wiki
[19:24] <mc-> I was going to suggest Pan-Atlantic
[19:24] <jcoxon> good name
[19:24] <Laurenceb> it doesnt involve pans :P
[19:24] <jcoxon> however i don't think i can survive another 'name' discussion
[19:25] <jcoxon> always the hardest part :-p
[19:25] <Laurenceb> hehe
[19:25] <mc-> also I was going to ask, are you switching off the GPS to save power between position messages?
[19:26] <jcoxon> ummm probably
[19:26] <jcoxon> thats natrium's department :-)
[19:26] <mc-> you need to have some way of collecting new ephemerides every hour
[19:27] <SpeedEvil> What's the uptime going to be?
[19:27] <SpeedEvil> under a week?
[19:27] <SpeedEvil> not really
[19:27] <jcoxon> 3 days
[19:27] <SpeedEvil> as long as you power it on for >30s
[19:27] <mc-> exactly
[19:27] <SpeedEvil> and a few mins a week
[19:28] <SpeedEvil> we don't really care about positional accuracy
[19:28] <SpeedEvil> the first fix may be off by a hundred meters - but so what.
[19:28] <mc-> you can save lots of power by switching on for a few secs every few mins, and then 30s every hour.
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[19:29] <SpeedEvil> then again, it's not really a big issue.
[19:29] <SpeedEvil> as the total power used by the GPS isnt' that high
[19:30] <jatkins> are you gonna use solar power?
[19:30] <SpeedEvil> one AA will keep it going for ~20h
[19:30] <jcoxon> jatkins, no, lots of banks of lithium energizers
[19:30] <jatkins> ok
[19:31] <jatkins> too high up in the clouds for solar?
[19:31] <SpeedEvil> Umm.
[19:31] <SpeedEvil> If there is sun down here...
[19:31] <jcoxon> no
[19:31] <SpeedEvil> solar is just annoying.
[19:32] <SpeedEvil> the panels can get cracked or broken easily, are moderately expensive, and heavy
[19:32] <jcoxon> hallam calculated that if you are doing more then a few weeks yes if not just batteries
[19:32] <SpeedEvil> 5 AA batteries forex will keep the GPS going for 4 days - conservatively
[19:32] <SpeedEvil> that's what - 100g?
[19:33] <jatkins> sparkfun do a 2.48 W panel @ 20 g
[19:33] <SpeedEvil> it's not 2.5W though
[19:33] <jatkins> (8V * 310 mA)
[19:33] <SpeedEvil> it's 2.5W when it's pointed directly at the noonday sun
[19:33] <mc-> then you need to multiply 100g by the ballast to keep it there
[19:33] <Laurenceb> look into powerfilm if you want solar
[19:33] <jatkins> i guess
[19:33] <SpeedEvil> average that when you rotate randomly, and you get maybe a third of that
[19:33] <SpeedEvil> in daylight
[19:33] <jatkins> ah
[19:33] <jatkins> ok
[19:33] <SpeedEvil> add in night-time, and you're now at maybe an eighth
[19:33] <SpeedEvil> neglecting clouds
[19:34] <jatkins> Laurenceb: thx, having a look
[19:34] <jcoxon> oh and its cold
[19:34] <Laurenceb> at altitude you have a bit more power
[19:34] <SpeedEvil> add charging efficiency, and somewhere near a tenth
[19:34] <SpeedEvil> So .25W might be a conservative ballpark
[19:34] <jatkins> yikes ... i see why no one uses solar
[19:37] <Laurenceb> could try solar thermal :D
[19:37] <jcoxon> jatkins, any progress with the radio?
[19:37] <jatkins> my soldering iron is broken, I'm getting a new one tomorrow
[19:38] <jatkins> twisting the wires on the headers ends up with the different wires touching each other
[19:38] <SpeedEvil> The above is somewhat pessimistic - but it gives a rough idea. Plus with solar, you've got to work out what to do if you get less or more power than you expect. With batteries, it's all lots more predictable.
[19:40] <jatkins> solar thermal would be nice if it wasn't so cold ;)
[19:40] <jatkins> and heavy
[19:40] <Laurenceb> I was joking
[19:40] <jatkins> yeah, i realize
[19:41] <jatkins> attach a balloon to http://en.wikipedia.org/wiki/File:Auroville_Solar_Bowl.JPG
[19:41] <SpeedEvil> gamma-ray sensor, some manoevering capability, and overfly russia
[19:41] <SpeedEvil> RTG for free!
[19:41] <jatkins> lol
[19:41] <jatkins> RTG lasts for about 14 years
[19:43] <jatkins> speedevil: couldn't you just set it up to automatically turn all the systems back on when the panel came in the view of the sun?
[19:43] <SpeedEvil> (instead of 18 hours, make that 28 hours one AA can run a typical GPS, I misremembered energiser compat)
[19:43] <jatkins> since you wouldn't need the electronics on the whole time
[19:43] <SpeedEvil> jatkins: yes, and how fast will you be spinning?
[19:43] <jatkins> ah
[19:43] <jatkins> yeah
[19:43] <SpeedEvil> jatkins: it's quite possible, it's just anohter layer of complexity
[19:43] <jatkins> yeah
[19:43] <SpeedEvil> jatkins: and at least for first attempts, it's not worth it
[19:44] <jatkins> it would work above the clouds, but since most of the mission isn't above the clouds, i can see how it's not helpful
[19:45] <SpeedEvil> Hmm. Energiser is ~300W/Kg
[19:45] <SpeedEvil> Wh
[19:48] <SpeedEvil> http://www.everspring.net/product-socl2.htm - ~500Wh/Kg - which isn't startlingly better
[19:50] <Laurenceb> those things suck under high discharge current
[19:50] <hallam> their D cells work out to 645
[19:50] <hallam> presumably at tiny current
[19:51] <Laurenceb> 3ma
[19:52] <Laurenceb> thats getting on for a years continuous operation
[19:52] <SpeedEvil> at low temps, it gets worse
[19:52] <SpeedEvil> at 20C, you can draw ~10mA and not affect the capacity much
[19:52] <SpeedEvil> do that at -30C and it about halves
[19:53] <hallam> I wonder what the mechanism behind that is
[19:53] <jatkins> bbl
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[19:53] <SpeedEvil> extrapolating down, it'd be 9Ah (not 18Ah) at 2mA and -55C
[19:54] <SpeedEvil> Be great - with a capacitor for a 'I'm floating' transmitter.
[19:55] <SpeedEvil> large capacitor, and wake up daily for a minute or so.
[19:55] <Laurenceb> or just use solar
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[20:00] <SpeedEvil> that too
[20:01] <Laurenceb> I was looking at some of my test data.. the inside of the mini rogallo heats up by about 10C after running for 15minutes
[20:02] <Laurenceb> kind of matches what was expected :P
[20:02] <Laurenceb> extropolating from that - you could keep an IMU at ~40C with <200mw extra power input
[20:03] <Laurenceb> so a heated IMU is probably the way to go
[20:03] <SpeedEvil> 40c?
[20:04] <Laurenceb> yeah
[20:04] <Laurenceb> centigrade
[20:04] <hallam> toasty
[20:04] <SpeedEvil> why?
[20:04] <Laurenceb> well the sensors themselves output a bit of heat
[20:05] <Laurenceb> so its hard to keep the temperature down at ground level and also avoid large energy input at altitude
[20:05] <SpeedEvil> ah
[20:05] <Laurenceb> and you really need a fixed temperature
[20:05] <Laurenceb> so about 40 seems reasonable
[20:06] <SpeedEvil> Water has 138Wh/Kg of energy storage going through 0
[20:06] <Laurenceb> I'm thinking simplest design would be a sparkfun 5dof imu with copper sheet onto then an mlx90609 mounted upside down on top
[20:07] <Laurenceb> then a small interface board with a uC, ADC, and some resistors
[20:07] <Laurenceb> next to the mlx90609
[20:11] <SpeedEvil> It has ~700Wh/Kg cooling from 120 to -10 :)
[20:12] <Laurenceb> lol
[20:12] <SpeedEvil> but that's harder to use
[20:12] <Laurenceb> whats the v2 badger board going to have?
[20:12] <Laurenceb> - sensor wise?
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[20:24] <SpeedEvil> Note to self.
[20:24] <SpeedEvil> Even though it is convenient, and avoids contamination, leaving the meat thermometer on its top, with the spike sticking up just next to the cooker is a bad idea.
[20:25] <SpeedEvil> http://www.sciencedaily.com/releases/2009/03/090309105026.htm interesting.
[20:25] Action: SpeedEvil really wants slow glass.
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[20:56] <edmoore> Laurenceb: you have used the leon core?
[21:02] <edmoore> hi jcoxon
[21:03] <jcoxon> hey edmoore
[21:03] <edmoore> s'happening?
[21:04] <jcoxon> working on that image
[21:04] <edmoore> funky
[22:14] <fergusnoble> Laurenceb: baro, temp, 3 axis accel and mag
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[23:00] <Laurenceb> in the name of god I have returned
[23:01] <Laurenceb> fergusnoble: no but its been used in the department
[23:01] <fergusnoble> Laurenceb: what?
[23:02] <Laurenceb> sorry just trying the iranian greeting
[23:02] Action: Laurenceb has been reading iranian space agency papers
[23:02] <Laurenceb> oh sorry
[23:03] <Laurenceb> that should have been addresses to edmoore
[23:03] <Laurenceb> :P need new glasses
[23:12] <edmoore> ok cool
[23:12] <edmoore> thanks Laurenceb
[23:13] <Laurenceb> Im not too familiar with vhdl
[23:13] <Laurenceb> played about with flashing leds ect
[23:13] <Laurenceb> but thats all
[23:16] <Laurenceb> its been used by guys here to make a gps receiver on spartan3 before, but they're using arm7 on actel pro asic now
[23:17] <edmoore> ok. just passing interest on some techy radio channel i was listening to whilst typing up a lab
[23:17] <edmoore> vaguely remember you mentioning it
[23:19] RocketBoy (n=Steve@217.47.75.27) left irc: "Leaving"
[23:30] Action: shellevil wonders ballistics.
[23:31] <shellevil> how long does dropping from 30-10km freefall take?
[23:31] <Laurenceb> f=ma
[23:31] <shellevil> yeah
[23:32] <shellevil> s=ut+1/2 at^2
[23:33] <shellevil> sqrt(4000) I guess
[23:33] <shellevil> 60s or so
[23:40] <edmoore> shellevil: what are you dropping?
[23:41] <shellevil> I was wondering about drop-tests for magnetic levitated flywheels
[23:41] <Laurenceb> lol
[23:41] <shellevil> For us poor people that can't easily get time in vomit comets.
[23:41] <Laurenceb> they are working on that here
[23:42] <Laurenceb> they were planning on a vomit comet
[23:42] <shellevil> this was that sloppily manufactured one you mentioned earlier?
[23:42] <Laurenceb> yes:P
[23:42] <edmoore> i spent a year working on magnetic lev bearings
[23:43] <shellevil> polishing them?
[23:43] <shellevil> :)
[23:43] <edmoore> desiging and tuning control systems. + more boring stuff
[23:43] <edmoore> like wiring up cabinets
[23:44] <shellevil> someone over in ##electronics arguing that in 1973, magnetic levitated energy storage flywheel would not have been an utterly insane design choice for a 29kg amsat
[23:45] <Laurenceb> edmoore: did they use magnetic induction in the rotor?
[23:45] <Laurenceb> so rotor is solid and coils are stationary?
[23:46] <edmoore> electro magnets in the stator, soft iron laminates in the rotor
[23:46] <edmoore> stationary coils, yep
[23:47] <Laurenceb> interesting
[23:47] <Laurenceb> so you magnetise it
[23:47] <edmoore> yep
[23:47] <Laurenceb> I can never work out if you could apply torque to a solid copper rotor
[23:48] <Laurenceb> by magnetic induction
[23:48] <shellevil> course
[23:48] <shellevil> take a bar magnet
[23:48] <shellevil> above a copper plate
[23:48] <edmoore> we used three phase induction on the rotors, but you had to start it off with an exciter
[23:48] <shellevil> spin bar magnet, and induce a torque in plate
[23:49] <Laurenceb> but arent you simply applying force to the electrons
[23:49] <Laurenceb> - the delocalised ones
[23:50] Action: shellevil passes Laurenceb a monopole.
[23:51] <shellevil> Imagine the currents flowing in an infinite sheet of finite resistivity when a monopole moves over it
[23:52] <shellevil> It results in a drag
[23:53] <Laurenceb> sure, but its not very efficient right?
[23:53] <Laurenceb> loads of energy wasted as heat
[23:59] <shellevil> well - so does everything :)
[23:59] <shellevil> the drag - looked at another way - is a torque.
[23:59] <Laurenceb> yeah
[23:59] <shellevil> int he above bar magnet over a copper disk case
[23:59] <shellevil> in the
[00:00] --- Tue Mar 10 2009