#robotics Logs
Dec 27 2012
#robotics Calendar
00:00 theBear http://www.pmillett.com/starving.htm 2nd image
00:00 KimLaroux http://diyforums.org/SSMH/SSMHvariants.php
00:00 KimLaroux this is the 12au7 version
00:00 theBear and that's the drain, not the source
00:01 rue_shop you cant operate the filaments like that
00:01 theBear and not even a cap on the filiament or the cathode, it's just horrible
00:01 theBear rue_shop, so now you agree it's a stupid circuit ? <grin>
00:01 KimLaroux rue_shop: you can't can't do what already is done
00:01 rue_shop hmm now I know the bias point for a IRC510
00:02 theBear yeah, and kim said it 5mins ago :)
00:02 theBear now we all know
00:02 rue_shop they are kinda current driving the fil by the quescent current thru the fet
00:02 theBear yeah, we see what they are doing, it's just, horrible, sure it gives some feedback, BUT AT WHAT COST !?!?!!
00:02 rue_shop there is no biasing on the grid, wt
00:02 rue_shop f
00:02 theBear think of the children
00:03 KimLaroux nah, we're limiting how high the source can go, by clamping the gate at 17v
00:03 theBear oh, at least that 2nd version has a cap on the cathode
00:03 theBear rue_shop, triodes are quite happy to pull bias thru the cathode (r11) and have none on the grid, it's common practice
00:03 rue_shop KimLaroux the REASON that old amps sounded so good was because of the engineering that was forgotten when transistors came out
00:03 theBear that's the drain !
00:03 rue_shop none of that old school stuff is in that amp design
00:04 KimLaroux http://www.societyofrobots.com/images/electronics_mosfet_schematic.png
00:04 rue_shop its not stuff that costs a lot, its just good practise stuff
00:04 KimLaroux am I really that stupid?
00:04 rue_shop like using a 300V plate supply with multi-megohm resistors
00:04 KimLaroux the lowest pin the the SOURCE
00:04 theBear oooh i don't like it at all
00:04 rue_shop I'm just sayin, even if that design works, its not gonna be good just because it uses tubes
00:04 KimLaroux s/the/is
00:05 rue_shop KimLaroux you grabbed this design cause it seemed like a simple one?
00:05 KimLaroux I don't care if it's good or not in your eyes. This project made me learn a shitload of stuff, and that's good enough for me
00:05 KimLaroux no, because it was weird
00:05 theBear now learn why it's a poor design in ANY designers eyes
00:06 KimLaroux and because it's a poor design in your eyes
00:06 rue_shop KimLaroux have you ever done tubes before?
00:06 theBear no, because it is technically FLAWED
00:06 KimLaroux nop
00:06 rue_shop ok
00:06 rue_shop want to walk thru a good design with the tubes you have?
00:06 rue_shop 12UA7 is a fine tube
00:07 KimLaroux wait
00:07 rue_shop I dont wait, I just move on
00:07 KimLaroux http://www.cavalliaudio.com/diy/soha%20ii/main.php?page=schematics/ampschematic
00:07 KimLaroux how's that?
00:07 KimLaroux the tube part, I don't care bout the output stage
00:07 rue_shop 60V is getting better
00:07 rue_shop they "improved" the resistors with a transistor current source
00:08 theBear err, that'd be a mirror methinks
00:08 KimLaroux it is
00:08 theBear very interesting
00:08 theBear it's a basic opamp with a tube in the first stage :)
00:08 rue_shop replace everyghing right of R8 with a transformer
00:08 KimLaroux yeah this guy uses tubes in a very interesting way
00:08 rue_shop he is just putting tunes in to make the projects look cool
00:09 KimLaroux yeah probably
00:09 rue_shop you could stick one in and ust light up the filament, it would sound just the same
00:09 rue_shop :0
00:09 rue_shop :)
00:09 theBear the way i see it, if yer gonna do a tube preamp that isn't pure tube, just do it with a single nice clean traditional tube gain stage or two, and leave it at that,you'll always do better
00:09 rue_shop theBear how did good tube amps get around freq dropout in the output transformer?
00:09 theBear rue_shop, you'd be surprised how many commercial products do that with the filiament
00:09 rue_shop oh
00:10 theBear rue_shop, all of them have neg feedback to around the phase splitter area or a stage earlier, and they just use nice big solid transformers
00:10 rue_shop headphones are 1k, a tube can drive that direct
00:10 KimLaroux eh no
00:10 rue_shop big transformer = high end dropout?
00:10 KimLaroux they are around 50 ohms
00:10 rue_shop hmm
00:10 theBear until recent RIDICULOUS (way beyond that last circuit) tube amp designs, they were ALL the same basic design
00:10 KimLaroux between 32 and 600, to be precise
00:11 KimLaroux mines are 47 and 62, I think
00:11 rue_shop what the output current rating for a 12UA7?
00:11 KimLaroux like 2 ma I think
00:12 rue_shop :) need some deflector tubes
00:12 theBear heh
00:12 KimLaroux yeah right
00:12 rue_shop KimLaroux how about I interest you in something really really obscure
00:12 KimLaroux buy 400$ worth of transformers for an headphone amp
00:12 rue_shop an amp based on a candle flame
00:13 KimLaroux seen it
00:13 theBear i could build you one and a half 100w marshalls for $400 worth of transformers
00:13 rue_shop ok
00:13 rue_shop exotic was the word I was looking for
00:13 theBear you gotta learn to tell the difference between products aimed at hifi idiots that don't know any better, and the same components at a reasonable price
00:13 rue_shop I mean the flame is the amplifer medium
00:13 rue_shop hmm
00:14 rue_shop KimLaroux I'll look up the 12UA7 later
00:14 rue_shop I have a manual around
00:14 rue_shop I'm going back to my robotic arm
00:14 theBear i wish i had a robot arm, and tank trails for feet, and a heart as black as coal
00:14 Jak_o_Shadows does it get lonely?
00:15 theBear being at the top ? nah
00:15 KimLaroux http://www.cavalliaudio.com/diy/bijou/main.php?page=ampschematic is this more proper to your eyes?
00:15 rue_shop yes
00:15 theBear stop saying our eyes, say something like 'according to the laws of electronic design'
00:16 rue_shop 250V is a proper supply, but the resistors should be larger
00:16 theBear yeah, much better, the phase splitting is a little cheap, but it IS a small and easily biased setup, and the neg feedback is nicely done
00:16 MjrTom I AM the law!
00:16 KimLaroux I'll submit to those laws when I get my EE degree, untill then can I just have fun?
00:17 theBear *pffft* this is ground control *pffft*
00:17 MjrTom Send me up a drink!
00:17 theBear i dunno, sounds like this whole bubbling tomato sauce isn't so much fun
00:17 rue_shop a good design about have a 22M resistor somewhere
00:17 theBear 22meg ? seriously ?
00:17 rue_shop iirc, yea
00:17 rue_shop dunno what for
00:17 theBear hehe
00:17 rue_shop red and green, thats whats important
00:18 rue_shop maybe a bit of blue
00:18 theBear but i can't see red OR green :(
00:18 theBear i am fond of blue
00:18 mLaroux facepa
00:18 KimLaroux You guys are just old
00:18 theBear nah, i could never see red or blue, and he's old, i'm young
00:18 rue_shop last one has proper flament supply
00:18 rue_shop and 250V has proper headroom
00:19 rue_shop I think that amp would sound good
00:19 rue_shop but it DOES use a number of moderm shortcuts
00:19 theBear if any of these suckers were half serious, at those kinda signal levels, they should be running nice isolated dc filiaments really
00:19 KimLaroux most do
00:19 KimLaroux the SOHA does
00:20 theBear oh, that'd be that diode thing...
00:20 rue_shop its a modern style N channel pushpull
00:20 rue_shop er pnp
00:20 rue_shop er npn
00:20 KimLaroux http://www.cavalliaudio.com/diy/soha%20ii/main.php?page=schematics/psschematic
00:20 rue_shop haha
00:21 theBear wow, the guy that made that smoked a lotta crack
00:21 rue_shop multipier to make it safer
00:21 KimLaroux I'd like to see you tell him to his face
00:22 theBear i'd be quite happy, then i could explain circuit by circuit why most of everything he has done is wrong
00:22 rue_shop the old amps directly rectified the mains, it was kinda scarry
00:22 theBear he would even get a chance to rebut, better than right now
00:22 KimLaroux this guy built one of the best headphone amplifier on the market today
00:22 theBear rue_shop, pfft, maybe ones more than double your age :)
00:22 rue_shop then they started installing MULTI winding transformers
00:23 theBear KimLaroux, can you prove that objectively, or just by testimonials from hifi idiots ?
00:23 rue_shop 50 wires out a palm sized transformer
00:23 rue_shop KimLaroux you just want to make a tube amp yes?
00:23 eBear wanders
00:23 KimLaroux I just want to learn and have fun doing so
00:24 theBear heh, build robots then :) there is much less math and unfun involved in that
00:24 rue_shop KimLaroux the tube is like a fet
00:25 rue_shop a really weak one
00:25 KimLaroux Fun is subjectif, I'Ve built robots but never found it as fun
00:25 rue_shop because they used such high voltages to generate the plate currents, the amps were almost unsaturable
00:25 KimLaroux they are collecting dust..
00:25 rue_shop which is part of why they sounded so good
00:26 KimLaroux saturable is in clipping?
00:26 rue_shop so making an amp with a 30V supply is kinda pointless, cause it can be easily saturated
00:26 rue_shop yes
00:26 KimLaroux not for headphones, no
00:26 theBear well they don't clip, but something like that
00:27 theBear well, they do, but in a saturatey kinda way, and the soft rails help too
00:27 theBear then again, 2 pairs of green 3mm leds back to back do the same thing in a much nicer way
00:27 theBear just ask marshall, they been using that for the drive stage since the mid 90's, yes, even in their 11+ tube amps
00:28 KimLaroux to do what?
00:28 theBear clip in a nice soft saturatey way
00:28 theBear marshall haven't overdriven a preamp tube since jcm900
00:28 KimLaroux I didn't get the point about the led
00:29 theBear 2 back to back leds behave a LOT like a tube stage, especially when driven hard
00:30 KimLaroux but tubes amplify... LEDs dont
00:30 theBear http://www.drtube.com/schematics/marshall/8080-pre.gif top left, http://media.beta.photobucket.com/user/stooty/media/DSC_0043-2.jpg.html?filters[term]=marshall%20valvestate%20circuit&filters[primary]=images two sets of red near the top
00:30 theBear doesn't matter when you got 20 opamps in yer 'tube amp'
00:31 theBear heh, i spose they got even cheaper in their design, used to be 4 leds, now it's just pairs of red
00:32 KimLaroux I see...
00:32 KimLaroux just checked, by headphones need 0.05 V RMS to reach 90 dB SPL
00:33 theBear 90dB is less than the background noise in a quiet bar
00:33 KimLaroux 0.06 mW
00:34 KimLaroux quiet bars are noisy =P
00:34 theBear i mean a QUIET bar, maybe 5 old alcaholics not talking
00:34 KimLaroux without music?
00:35 theBear of course without music
00:35 theBear snare drum from 50meters easily breaks 100dB
00:35 theBear and that's not a hard hit
00:36 theBear trust me, i used to work regularly in places with STUPID noise restrictions
00:36 KimLaroux yeah... all the bars I went to had music so loud you had to yell for the people sitting in front of you to hear
00:37 theBear yeah, i don't much care for that kinda thing unless i'm working... i choose dark quiet bars with a nice community of regulars and staff, dark wood decor, little or no background music
00:38 KimLaroux I choose no bars... seems easier that way
00:38 theBear mmm, i don't go to a lot these days, but i need a steady intake of alcahol to stop me going postal on everyones asses, so if i run out, i run to the nearest bar
00:38 KimLaroux Looking at the side of the bad socket, it's very dirty...
00:39 theBear plus, as part of my Act Belong Commit mental health strategy, i spent a lot of time at a bar before i was crippled last year, and it made my life MUCH richer
00:39 mLaroux takes out the flux cle
00:39 theBear got contact cleaner ? it's more appropriate
00:39 KimLaroux oO
00:39 KimLaroux the dirt is flux dirt
00:40 theBear really ? how you get flux in a valve socket ?
00:40 KimLaroux by soldering a wire to the pin?
00:40 theBear but the pin is at the other end
00:41 KimLaroux http://i00.i.aliimg.com/wsphoto/v0/325730826/2PC-Ceramic-font-b-Tube-b-font-font-b-Socket-b-font-9-Pin-B9A-Base.jpg
00:41 theBear general tip, if yer having trouble soldering to things, give them a little abrasion/sanding before you start
00:41 KimLaroux I usualy use a knife
00:41 KimLaroux but my solder has a little bit of flux in it, so it gets everywhere
00:41 theBear that works, there is no reaosn for flux OR solder to be anywhere more than a few mm's from the end of those pins
00:42 KimLaroux I can give you reasons if you want... innexperience will be the first
00:43 theBear mmm, i let you off, just keep it in mind as you practice
00:43 KimLaroux there are reasons for everything that is, or else these things would not be... this thing called "causality"
00:43 theBear and of course clean it now, but that doesn't really explain why things would be pulled lower than they should... maybe if that crazy filiament arrangement had a bad contact i suppose
00:46 theBear things like that are often radically affected by wiggling/rotating the tube a little in the socket while observing the circuit/output, sometimes temporarily fixed, or at least obviously influenced if that is the problem
00:47 theBear as in err, put a couple fingers on the top of the tube and move them in a circle parallel to the plane of the base
00:49 KimLaroux I tried that, but it didn't affect the noise
00:50 theBear if you got a scope i'd be looking for unexpectedness at the plate and either side of the coupling cap
00:50 KimLaroux yeah, sadly I don't have one
01:07 theBear not gettin any cooler, thank god rue didn't eliminate beer from history earlier, cos i'm almost outta gin
01:12 KimLaroux if you're curious, here's pictures of my amp http://www.head-fi.org/g/a/657814/
01:13 theBear mmmm... nie case, and very nicely assembled for a beginner
01:13 theBear hmm, how did it change colour halfway thru ?
01:14 KimLaroux I changed enclosure
01:14 KimLaroux the plastic one cracked
01:14 theBear bummer, i always been fond of seethru plastic cases, but at the same time have very few if any left for that reason
01:15 theBear my first non-kit poweramp was made on red perspex
01:15 KimLaroux I learned that PMMA will shatter under stress when it gets in contact with a solvent
01:16 KimLaroux and thanks
01:16 theBear mmm, makes sense
01:16 theBear hmm, should build that psu i've head-designed and got probably all the bits for while i got some time off
01:17 theBear always wanted a fancy bench psu, now is the time
01:17 theBear dan dan, dandan dan dan, justice league
01:17 theBear heh, couldn't help myself, don't think it's even the justice league theme, but to quote captain murphy "hahaaaa, wrong melody"
01:18 KimLaroux o.0
03:12 rue_house I made a toool
03:19 TELunus What kind of tool?
03:22 rue_house one moment
03:23 rue_house !assist projects/lathe
03:23 tobbor Possibly http://eds.dyndns.org/~ircjunk/projects/lathe
03:24 rue_house http://eds.dyndns.org/~ircjunk/projects/lathe/p1040793.jpg
03:24 rue_house that is the tool
03:24 rue_house http://eds.dyndns.org/~ircjunk/projects/lathe/p1040788.jpg <-- you use it like that
03:24 TELunus Ah.
03:25 rue_house http://eds.dyndns.org/~ircjunk/projects/lathe/p1040788.jpg <-- to make THESE!
03:25 rue_house http://eds.dyndns.org/~ircjunk/projects/lathe/p1040795.jpg <--- mmmmm
03:26 TELunus It's for mounting a free-spinning workpeice eh?
03:26 Jak_o_Shadows Is it possible to make a hollow threaded plastic rod? With the threads on the outside?
03:26 rue_house I have to clean it up, but its 1am and if I use a grinder outside there will be more torches and pitchforks than I can shake a stick at
03:26 rue_house Jak_o_Shadows, yes
03:27 rue_house Jak_o_Shadows, at the hardware store, you can buy them for lamps
03:27 Jak_o_Shadows Yes, i know, i've just never bothered looking
03:27 rue_house TELunus, worm drives...
03:28 rue_house I have to use the tablesaw outside too, so tommorow is going to be busy
03:30 TELunus Still on holidays tomorrow?
03:30 rue_house yes
03:30 TELunus Cool, perhaps I'll swing by.
03:30 rue_house cool
03:30 rue_house I should be awake by 12:00 or so
03:31 rue_house :)
03:31 TELunus Ok.
03:31 TELunus I might try my cabels out in the snow again before then.
03:32 TELunus head up the mountain.
03:32 rue_house .... ?
03:34 TELunus I bought some cabels for my parents' car, for a road trip in February. Gotta get used to driving with them.
03:34 rue_house oh for tires
03:36 TELunus Ya.
03:37 TELunus Some people seem to mix them up with chains, but it turns out there's a differance.
03:39 rue_house my understanding is that chains are for more serious depth
03:46 TELunus Ya, they also require more clearance and as such are not suitible for a Toyota Corrolla. Aperanly chains may also be more durable.
03:47 TELunus I might wind up borrowing my brother in law's 4x4, which will be much nicer than using a Corrolla.
03:50 rue_house hmm
11:44 zero_coder hi
11:44 zero_coder anyone creates robots?
12:01 zero_coder hey
12:01 zero_coder where do i start robotics with?
12:03 spagetti hi everyone
12:04 spagetti i have a question http://www.reddit.com/r/AskElectronics/comments/15izcu/how_would_i_start_building_a_robot_that_when_it/ also i forgot the pw to my account but any answers would be much appreciated!!
12:06 GuShH lawl
12:08 zero_coder i am also thinking of building my first robot
12:08 GuShH you two should get together
12:09 spagetti i wana build one without using any microchips or coding
12:09 spagetti b/c that's cheating
12:09 GuShH ...
12:09 GuShH oh so it's stupid time already?
12:09 ShH gets rid of his p
12:09 spagetti why did you have them on in the first place
12:10 GuShH good question
12:13 spagetti zero coder doesn't have what it takes to make an analog robot
12:13 GuShH neither do you!
12:13 spagetti HA
12:13 GuShH HA!!!!!
12:13 spagetti i have exactly what it takes
12:13 spagetti 0 knowledge of robots
12:13 GuShH and no pants
12:14 spagetti minimal knowledge of circuits
12:14 nardev can you suggest me some cheep, up to 60$ 4w platform preferably available to buy online?
12:14 spagetti it's a recipe for success
12:15 GuShH here's a cheesy song for your robot montage http://www.youtube.com/watch?v=nBC3weWCX_E
12:27 zero_coder hey , where do i get started?
12:28 spagetti https://solarbotics.com/product/k_pp/
12:28 spagetti i found this
12:28 spagetti imo the idea behind this thing is freaking awesome
12:30 zero_coder i mean where should i start learning robotics?
12:32 zero_coder #ai
12:57 spagetti https://solarbotics.com/product/k_pp/ do you guys think this is a good deal
13:04 jennie #psychology
13:22 spagetti hey guys
13:22 spagetti what's your favorite robot
13:43 GuShH spagetti: the one that goes "beep beep bop" and then "boop boop"
13:43 spagetti If your robot goes bop instead of boop you fucked something up
13:44 GuShH it's their language I don't make the rules
13:45 MjrTom if I make a robot that made noises like that, I'd fix it right away
13:50 spagetti you'd fix it by making the beeps and boops louder, right?
13:51 spagetti louder sounds mean it's working harder
13:53 MjrTom thats the job of the machine that goes bing
13:53 MjrTom (and why you want to have the most expensive one)
13:54 GuShH lol
14:29 KimLaroux Well, it seems like the problem with my amplifier really was dirt in the socket
14:29 KimLaroux I cleaned it last night, let it dry over night, and today it's perfectly quiet
14:29 exiff dirt will be the end of us all
14:30 KimLaroux flux is a double ended sword
14:32 KimLaroux It wants you to use more, it makes you addicted to it... then it stabs you in the back
14:36 spagetti flux is training wheels
14:36 spagetti i use spit
14:52 spagetti excuse me but can you charge up a solar panel from a light bulb
14:52 Tom_itx no
14:53 Tom_itx light bulb isn't a solar pannel charger
14:53 Tom_itx solar pannels don't need charging
14:55 spagetti i mean can solar panels get energy form lightbulb
14:56 Tom_itx not much
14:56 Tom_itx not enough to balance what the bulb uses
15:26 spagetti yah energy will be lost for sure
15:28 rue_bed wow
15:28 rue_bed I slept
15:29 rue_bed I need to get things done
15:29 rue_bed Tom_itx, did you see the toys made last night?
17:05 rue_house hmm, 2pm, I should have lunch
17:14 Tom_itx what's it for?
17:14 Tom_itx i supported the tap with the tailstock
17:18 qasd I want to build a mini(unmanned, < 1meter long roughly) submarine that i can send out to sea with a camera in it. to transmit wirelessly , would that be complicated and expensive because being underwater?
17:20 Tom_itx http://www.huv.com/uSeeker/index.html
17:23 rue_house http://eds.dyndns.org/~ircjunk/projects/lathe/p1040788.jpg <-- to make THESE!
17:23 rue_house http://eds.dyndns.org/~ircjunk/projects/lathe/p1040795.jpg <--- mmmmm
17:23 rue_house http://eds.dyndns.org/~ircjunk/projects/lathe/p1040788.jpg <-- you use it like that
17:23 Tom_itx yeah i saw those
17:23 rue_house qasd, start with a teathered one
17:23 Tom_itx what's it for?
17:24 rue_house http://eds.dyndns.org/~ircjunk/projects/lathe/p1040788.jpg <-- to make THESE!
17:24 rue_house worm drives
17:24 Tom_itx what's it for?
17:24 Tom_itx what are you gonna use them on?
17:25 rue_house worm drives, I can use them for anything
17:26 Triffid_Hunter qasd: wireless doesn't travel through water
17:26 Triffid_Hunter qasd: in fact, very few radio signals do
17:27 rue_house Triffid_Hunter, it does if you use REALLY long wavelengths with VERRY long antennas
17:27 Tom_itx why they use sonar
17:27 rue_house I think subs tow an antenna thats ~few miles long
17:27 Triffid_Hunter rue_house: yeah sure, I don't think qasd is planning on putting a 1km antenna with an ELF transciever on his sub though ;)
17:28 rue_house hence me suggesting teathered
17:28 Tom_itx or store data and surface to transmit
17:29 rue_house we been had again, our subject exited
17:29 Tom_itx no, just silent
17:30 rue_house well I have a 1/2" peice of plexiglass to turn into a robot arm base
17:30 rue_house money to put in the bank
17:30 Tom_itx rue_house, make some of these tonight: http://tom-itx.dyndns.org:81/~webpage/reprap/drive6.jpg
17:31 rue_house do they sell?
17:31 KimLaroux rue_house: how did you figure the right radius so the teeth all lign up?
17:31 rue_house did you use the same kinda setup?
17:31 Tom_itx i just made two but somebody wanted to buy them
17:32 Tom_itx similar
17:32 rue_house KimLaroux, I jammed it into the bit and fate worked out the rest
17:32 Tom_itx i supported the tap on both ends
17:32 KimLaroux LOL
17:32 Tom_itx and my cross slide fixture was open ended
17:32 KimLaroux that works XD
17:32 Tom_itx so it could ride where it wanted to
17:32 Tom_itx i guesstimated the root diameter
17:32 rue_house hmmm
17:33 Tom_itx so it would come out even
17:33 rue_house thats #4 or #6 tho yes?
17:33 Tom_itx 3
17:33 rue_house yike
17:33 Tom_itx :)
17:33 Tom_itx you up for it?
17:33 rue_house oh, thats a 1" square yes?
17:33 Tom_itx it's stainless and brass
17:33 Tom_itx no
17:33 Tom_itx not on the mat
17:33 rue_house na, the money isn't worth the time
17:34 Tom_itx i just wanted to do it
17:34 rue_house :)
17:34 rue_house I have to put the limit switches on the reprap too
17:34 Tom_itx those are more like 2" squares
17:35 Tom_itx i didn't measure them though
17:35 rue_house ah
17:52 qasd Triffid_Hunter: so how does real submarines coomunicate with land while underwater?
17:53 Tom_itx surface
17:53 Tom_itx or sonar
17:53 Tom_itx or longass antenna
17:54 qasd Tom_itx: yeah thats an idea ive been thinkling of. but lets say that you surface in the middle of the atlantic, could you possibly transmit over those distances with hobby equipment(im willing to invest say 3000$ in this)?
17:55 Tom_itx you would likely need a mother ship or satelite
17:55 qasd wont i have distance problems with the satelllite as well?
17:56 qasd but with sonar id need an underwater transceiver
17:56 Tom_itx those are some of the issues you will have to work out
18:02 Triffid_Hunter qasd: they use satellite when they surface afaik, or shortwave radio or something
18:03 Triffid_Hunter qasd: when underwater they're generally completely cut off but in emergencies they can deploy a very long antenna (>1km) and use extra low frequencies down in the audio spectrum
18:03 qasd >1km!?
18:08 Triffid_Hunter qasd: yes
18:09 Triffid_Hunter qasd: the wavelength at 30khz is ~10km so it's a compromise, they need a base loading inductor as well
18:09 Triffid_Hunter qasd: but that's what you need to punch radio waves through water
18:10 qasd how do they actually get that thing out and keep it floating?
18:11 qasd 10km!? really
18:15 qasd would pressure effect the wavelength of the signal?
18:40 Triffid_Hunter qasd: no, the wavelength is controlled by the transmitter
18:42 qasd and the pressure of asl the water cant effect the wavelength of th signal?
18:43 qasd hmm,so i really want to let it out in the ocean and not be limited to 40m cable(i dont have a boat either so cable pretty much kills most of the fun although i might start with that). so 1. surface to transmit or 2. use sonar and an underwater transceiver then cable from transceiver to com. But im gonna send video here. is sonar suitable to send that?
18:43 Triffid_Hunter qasd: lol, no
18:44 Triffid_Hunter qasd: neither is sonar, and if you run video over a satellite link it'll cost you a fortune
18:44 Triffid_Hunter qasd: if you want to drive a ROV around in your local pond, go tethered
18:48 qasd Triffid_Hunter: you say neither is sonar. but i could send the video with sonar no? just code it somehow and then decode in computer linked with transceiver?
18:50 qasd surface to transmit obv means i cant control it while underwater which is a bit bad.
18:51 qasd and using sonar to transmit and receive data, is that a good idea?
18:51 qasd guess ill just start with something cabled.
18:54 KimLaroux qasd: how deep do you want it to go?
18:54 KimLaroux a simple solution would be to tether the sub to a floating buoy, and place the radios on the buoy
18:56 qasd KimLaroux: well id like it to go to the bottom of the big oceans but realicstially i guess id start with something like 20m deep. ill look into cable options tomorrow.
18:56 qasd what protocol would be suited for this? transmitting video over shoirt cable lengths?
18:57 KimLaroux just use whatver protocol the camera is using...
18:57 qasd about the bouy then id still be limited in searchable space but i guess cool things could pass by :)
19:03 Triffid_Hunter qasd: eh possibly if you send it holographically, like dolphin speech
19:04 qasd ?
19:06 Triffid_Hunter qasd: dolphins transmit holographs when they communicate, complete 3d images, probably including their thoughts about what's happening in them
19:06 Triffid_Hunter they closely resemble the holographs they receive when bouncing their clicks and whistles off things
19:08 qasd im being serious on this end
19:09 Triffid_Hunter qasd: can't think of another sensible way to transmit usable video with soundwaves, more conventional methods simply don't have the data rates you need
19:09 Triffid_Hunter it's easier with radio because the carrier frequency is generally a lot higher
19:13 Geeks2Go SOP is tethered ROV using fiber for data and copper for power..
19:13 Geeks2Go hi
19:13 tobbor hi Geeks2Go.
19:13 Geeks2Go Hey tobbor
19:13 GuShH geeks-b-gone
19:14 Geeks2Go my ex wives have a patent on that
19:21 qasd Triffid_Hunter: you were joking about the holographs right?
19:45 Triffid_Hunter qasd: just as much as you were joking about sending video over sonar ;)
19:51 Geeks2Go qasd- if you can access a copy of thiis book you can find the answer to most any ROV question you might have http://www.marinetech.org/underwater_robotics/
20:02 qasd ty
20:04 rue_house make a teathered one
20:05 rue_house if you haven't built one before, you want it to have a teather anyhow
20:05 rue_house if you really want, make the teather a coax cable, and you can say its operated via RF
20:05 rue_house ;)
20:06 rue_house bah
20:07 qasd yeah i will go tethered
20:07 qasd goodnight, ty for the input
20:08 rue_house what design you gonna use, how many mtoors?
20:08 rue_house mine has 4
20:08 rue_house one thrust and 4 for roll/nose position control
20:36 spagetti hi
20:36 tobbor Hello spagetti
20:37 spagetti http://www.motors.wrobots.com/MDN3BT3CSAS.php can i attach a 9v battery to this
20:48 spagetti http://www.motors.wrobots.com/MDN3BT3CSAS.php does it matter which way the wires are connected to this
20:48 spagetti positive to negative
20:52 spagetti ok i tested it and the answer is no