#qi-hardware IRC log for Monday, 2014-04-21

DocScrutinizer055GHz? I'm still amazed and puzzled that such high frequency still can use cables at all03:59
DocScrutinizer05plus the wavelength on free air is prolly short compared to the twisted pair turns-per-inch04:01
DocScrutinizer05(too lazy to calculate it now)04:01
DocScrutinizer05http://www.wolframalpha.com/input/?i=5GHz   60mm04:03
DocScrutinizer05btw do you think file:///home/whitequark/Downloads/327216.pdf is particularly informative?04:44
DocScrutinizer05maybe I could deduce where to find it via html://, but I rather go have another short nap04:45
sb0so I had a look inside the faderfox09:17
sb0everything is on a single PCB; seems they managed to find compatible COTS parts09:17
sb0I noticed that the faderfox is no longer sold; maybe one of those parts got obsolete sending them straight back to ME hell09:18
sb0I also noticed that the knobs on the encoders have a position indicator (which means nothing), which confirms my experience that you cannot source a small knob without an indicator09:19
sb0and everything is encoders - no pots. I could not find a compatible pot/encoder combination...09:27
sb0also, the search engines of component distributors are frustrating. they only let you search by petty characteristics like resistance, linear vs. log, number of taps on the resistor, etc. which are trivial to adapt to in the electronics09:29
sb0the parameters you want is: shaft length, bushing length, body size, etc.09:29
sb0and the "suggested products" in each component page often show stupid stuff like max232 or AVR ucs09:51
sb0what I'd rather see is "encoder/pot/slider you can mount on the same PCB and it'll look good" ...09:52
sb0e.g. http://de.mouser.com/ProductDetail/ALPS/RS6011SP6003/?qs=/ha2pyFaduig0GHhvG2PgbVvcpG1OsX2nf%252bVAv/l3rE8zPJLxL0tcQ==10:23
sb0what you want is a knob that mounts on it (which is, actually, a pain in the ass to find) - not AVR stuff, resistors, capacitors and switching regulator10:24
sb0oh, another thing I notice right now is this stupid pot went out-of-stock even though I ordered some last week10:27
sb010 weeks lead time now. nice!10:27
sb0yeah, I should definitely go panel-mount10:30
wpwrakyeah, most of those "parametric searches" are crap (if they have them at all)10:32
wpwrakpanel-mount sounds like a good choice also for ruggedness10:33
wpwrakelse, you could try to arrange controls in height groups and give each its own little PCB, then make a custom spacer that puts each board at the right height10:34
wpwrakif something returns to the land of unobtainium, you simple redo that sub-PCB and make a new spacer10:35
wpwrakand yes, such things going out of stock is a constant nuisance10:35
sb0yeah, I'm going to go the many-PCB route10:36
sb0or even no PCB at all, solder wire directly on the part's terminals10:36
sb0if it can be mounted without PCB10:37
DocScrutinizer05sb0: you heard of those awesome electronic poti chips that get controlled from encoder by steeping up/down the poti property in dunno 64 or 128 increments, via pulsing 2 inputs10:37
DocScrutinizer05I guess you could use a encoder to pulse those stepper inputs10:38
wpwrakDocScrutinizer05: i don't think he needs analog pots (in the end, it all goes to the FPGA). just something smooth and rotary10:38
sb0the output of the analog pot needs to be digitized anyway, so using an encoder would actually simplify things a little (though such electronics problems are negligible compared to mech problems)10:38
sb0the problem is that I need a zero position10:38
sb0and encoders can be rotated continuously10:38
wpwrakpush-to-zero ?10:39
sb0push-to-zero is a bit counterintuitive10:39
wpwrak"innovative" :)10:39
sb0not very good user experience compared to a pot that acts like an analog volume pot (as it should)10:39
DocScrutinizer05well, when you could use *any* *arbitrary* poty since it's just for digitizing anyway, then I have a hard time thinking you couldn't find a single one that matches your mechanical requirements10:42
DocScrutinizer05also it's a very common practice to place the poti on PCB and just cut the axis to length you need to exactly come out of your front plate far enough to conveniently attach a knob10:44
DocScrutinizer05poti axis is available up to 15cm iirc10:44
DocScrutinizer05I seen several cut poti axes in commercial devices10:45
DocScrutinizer05ideally your aperture/hole in front plate is narrow and exact enough to give a sort of bearing to axis10:46
DocScrutinizer05or, when your poti or encoder simply have too short axis, then there's always axis extensions to attach to the too-short axes of encoders or potis, and then cut *those* to be same length as the longer right-length ones10:51
DocScrutinizer05there are even blind axis frontplate mount thingies, you could use a steel spiral spring you "plug" to their inner end, stretch the spiral spring to sufficient length and plug it to the original poti axis10:53
DocScrutinizer05advantage: you have a 20% adjusting headroom by the spring, which simplifies greatly the exact ME10:54
DocScrutinizer05usually you will stretch the spiral spring just so much that it is a maybe 5..10mm "too short", then the "missing" length is taken care during fixing of frontplate blind axis by elastic extension of the spring10:57
DocScrutinizer05I.E. you grab the axis stub coming out of frontplate and pull the whole thing out till it is flush, then fix the nut holding the frontplate blind axis in place10:58
DocScrutinizer05downside: this design has the potential to break when somebody applies too much force to it - but then otoh potis with rigid axis do as well11:00
DocScrutinizer05just on this design it's only the spring that gets twisted or even breaks when you turn the know 3 turns 11:00
sb0the PCB needs to be pretty close to the front plate due to the buttons11:01
DocScrutinizer05I guess the springs have a special shape of the wire they are made from11:01
sb0(if I go the single-PCB route, but I guess I won't)11:02
DocScrutinizer05oooh, so you try to find potis that are as low profile as your buttons are? well, this might turn out to be a mission impossible11:02
sb0ideally, the pots are screwed to the front plate using their busing, too11:02
sb0so the PCB cannot bend or break11:03
sb0even when the knobs are handled roughly11:03
sb0my current preferred approach is to use only that bushing11:04
sb0for rotary pots and encoder11:04
sb0and connect via flying wires to PCB11:04
DocScrutinizer05btw a common problem with several (cheaper) builds of slider potis: they easily get damaged by user "hitting" down the slider knob and thus breaking resp damaging the resistive trace11:05
sb0this way, I also don't give much of a crap about the body size or pin layout of whatever pot/encoder is stocked today11:05
DocScrutinizer05they also collect dust and debris via the slot for the slider knob11:05
sb0the slider pot is also a source of trouble right now11:06
sb01) hard to find a knob for it11:06
DocScrutinizer05sb0: yes, that's a *very* reasonable approch for this type of device11:06
sb02) if I use its mounting holes, I need to put screws on the front plate11:06
DocScrutinizer05thought of electronic "slider" made of sensors?11:06
wpwrakcould a capacitative slider be an alternative to a mechanical one ?11:06
wpwrakgreat minds think alike ;-)11:07
sb0maybe I'll mount it on a small dedicated PCB11:07
wpwrakyeah, eating breakfast and reading the news in parallel slows me down ;)11:07
sb0to solve #2. then I'm free to use threaded spacers, possibly welded behind the front plate11:07
DocScrutinizer05hmm, good idea. Time for another coffee11:07
DocScrutinizer05forget welding of anything to that case11:08
sb0(capacitive slider) not really, I want the "fader" feel like on audio tables11:08
DocScrutinizer05will turn out to be a nightmare, and ruin your surface11:08
sb0even welding from behind?11:09
sb0hmm, yeah, the weld might burn the powder coat...11:09
DocScrutinizer05glue or snap, or forget about it11:09
sb0is there any chance that glue will be resistant enough?11:10
DocScrutinizer05probably yes11:10
sb0even to attach spacers, which then receive screws which are mounted with some amount of torque, and then take whatever abuse the user gives to the fader?11:11
sb0well, maybe screws in the front plate are good enough for v1 :)11:12
DocScrutinizer05no, but you could weld (or whatever) the spacers to a dedicated mounting plate and then glue that plate to inside of frontplate11:12
sb0it's not like I've been in this hell for months and I'm very fed up about it11:12
sb0ah, yes, good idea11:13
sb0thanks :)11:13
sb0I won't need glue, since I could use the pots with bushing for attaching that plate11:14
sb0it's more milling work, though11:14
sb0to make all the holes in that plate11:14
wpwrak(mounting plate) as a general rule, the more you can do in 2D, the easier. limit fancy 3D milling/molding/printing to what you strictly can't avoid.11:15
wpwrak2D milling is trivial compared to 3D ;-)11:15
DocScrutinizer05drilling a few holes through a stack of 50 flat mounting plates is trivial11:18
sb0actually, I could use that plate as support for the screen's glass, too11:18
DocScrutinizer05yes, you could11:19
sb0this way I don't have to 1) find unsourcable and expensive highly-resistant thin glass (gorilla etc.) 2) mill a groove in the top surface of the case to support it11:19
sb0so the second plate looks like a very good idea11:19
DocScrutinizer05sure it is ;-D11:19
sb0I can also adjust its height to make the knobs reach the proper position11:19
wpwrakand you can make a spacer if you have to. again, cut from a board of known thickness. e.g., pre-colored acrylic11:19
wpwrakin the end you may have a lot of mechanical parts but if they're all relatively painless to make, it's still easier than finding the one holy grail that solves all your problems11:20
DocScrutinizer05check how commercial stuff like e.g. home stereo is doing it, thay *all* have a mounting plate and they have a frontplate to go parallel to the mountingplate11:21
wpwrakyeah. direct-to-pcb is a relatively new thing and basically needs a lot of people doing almost the same thing, so it makes sense to produce lines of matching components11:23
wpwrakof you need to "patch" things. e.g., buttons with intermediate knobs or the the pot-tery DocScrutinizer05 mentioned11:23
DocScrutinizer05direct-to-PCB is first and foremost a cheap "trick"11:24
sb0cheap? :)11:24
DocScrutinizer05yes, it's done because for huge batches it#s cheaper than proper mounting plate design11:24
DocScrutinizer05much cheaper11:24
DocScrutinizer05saves a lot of manual assembly expense, and quite a number of mech components11:31
DocScrutinizer05but it's flimsy and doesn't provide any proper repair-path11:32
wpwrakand it's also pleasant for the designer - you control all the key parameters of your product's geometry with the layout alone11:32
wpwrak(repair) toss bad pcb, insert good new one. after all, it's cheap :)11:33
DocScrutinizer05built to get discarded11:34
wpwrakwell, if you draw a graph of cost to replace and value of repair (that is, cost to replace - cost of repair - benefit of replacing old with new), you have the cost reduction not once but even twice in that formula. so if it makes sense to do the pcb approach for new items, it makes even more sense to not repair them.11:36
DocScrutinizer05for stage proven rugged devices PCB mount isn't the design of choice anyway11:38
DocScrutinizer05it's simply too shoddy for that rough treatment11:39
wpwrakwell, i suppose you can stabilize small PCB. they're still nice for connectivity. much easier to debug a messed-up assembly than with a ton of manually sold wires11:42
wpwrakbut yes, anything on which significant forces work, especially pots and such, should better not depend on the PCB for mechanical stability11:43
whitequarkDocScrutinizer05: oh fuck. Ctrl+C didn't copy the proper link. http://www.usb.org/developers/whitepapers/327216.pdf11:45
DocScrutinizer05s/and such/and any kind of jacks/11:46
DocScrutinizer05and pushbuttons, they should get their own small PCB with proper mech support when they are PCB type11:47
DocScrutinizer05a design like (mountingscrew)_____<pcb>_______(pushbutton)____(pushbutton)____(pushbutton)_____<lots-of-PCB>____(mounting-screw)   is usually a design gauranteed to break sooner rather than later. The PCB is not meant nor built for coping with mechanical load11:50
Action: whitequark reads http://hackaday.com/2014/04/21/whats-inside-a-usb-isolator/11:52
whitequark"[Lindsay] followed [Ben Krasnow]s video tutorial on how to decap chips, but replaced the nitric acid with concentrated sulphuric acid, which is a bit easier to obtain."11:52
wpwrakof, the pcb flexes very nicely. and you get beautiful microfractures in the traces to examine as well :)11:52
whitequarkclearly they never actually tried to obtain them11:52
sb0any good source for slide pot knobs?11:53
wpwrakwhitequark: things seem to be a little weird in russia. i guess it's much easier to get a kilo of Pu than a liter of HCl ;-)11:54
Action: wpwrak wonders whether they have at least the decency to put the Pu in the upper shelves, out of reach of the smaller children in the supermarket11:55
whitequarkwpwrak: well, Pu is definitely not considered a precursor for drugs11:55
whitequarkat least not for the drugs they want to regulate11:55
whitequarkso here's that11:55
wpwrakhmm. it's toxic -> should make a suitable drug :)11:56
whitequarkI actually wonder how hard would really be obtaining a warhead11:56
whitequarkwhat if our military bases are about as secure as OpenSSL? that's a scary thought11:57
wpwraktake two bottles and vodka and visit the next scrapyard ?11:57
whitequarkthat's how the jokes usually go, yes11:58
wpwrakthere's probably a big red button right where the head of the operator normally comes to rest when he's drunk himself into a coma again. fortunately for mankind, the contacts are too corroded to actually make contact ...11:59
sb0one of the funniest openbsd changes in openssl lately is "remove support for big-endian i386 and x86_64"12:00
whitequarkyou mean funnier than the constant stream of VAX/VMS removals?12:00
whitequarkseriously, it's like openssl contained United States' strategic reserve of VMS code12:00
sb0at least VAXen are existing machines :)12:01
whitequarkwell, by this definition dinosarus exist too, to some degree of "existence"12:02
wpwraksb0: grmbl. soon, they'll drop support for PDP byte order too :( (PDP had mixed little and big-endian, one at the 16 bit level, the other at the 32 bit level, forgot which way it was. so 0xaabbccdd became something like { 0xcc, 0xdd, 0xaa, 0xbb })12:04
larscthere seem to be some people which run big-endian code in x8612:05
wpwrakwhitequark: there probably are numerous vaxen still in operation12:05
wpwrakwhitequark: and some of them probably doing highly mission-critical tasks. tasks too important to risk changing the platform.12:06
wpwrakwhitequark: e.g., there was some plant, may have been hydroelectric, in switzerland that bought old PDP-11 in the mid-1980es, for spare parts to keep their super-critical process control units running12:08
whitequarkwpwrak: yes yes yes, I know, I've read an article in usenix (I think) about some atomic power plant which replaced PDP-11 with emulated PDP-1112:18
whitequarkstill, mission-critical infra hardly runs openssl... at least I hope so.12:18
whitequarkwpwrak: which way? there's an easy way to remember. UNIX (BE) ’ NUXI (PDP11E)12:19
whitequarkI don't think this fact will *ever* be useful in my life though12:19
DocScrutinizer05((at least I hope so)) dreamer!12:24
Action: DocScrutinizer05 wonders how many M80 are still running on the windows emu, using BS-M operating system12:26
DocScrutinizer05then OTOH they were built til at least 1990, so prolly not EOL time for such a SIEMENS product12:27
DocScrutinizer05IOW I'd not be surprised if you still can buy PROMEA-M in original package from SIEMENS, for maybe 10k bucks or somesuch12:28
DocScrutinizer05hmmpf, at least cables ;-P  https://www.google.com/search?q=PROMEA+siemens12:31
whitequarkwhat *is* PROMEA-M?12:31
DocScrutinizer05Programmable Multi Eingabe(input)Ausgabe(output). A monster UART12:38
DocScrutinizer05size of a usual contemprary PC mainboard12:38
whitequarkwow, a light pen12:39
DocScrutinizer05SICOMP Mxx computers12:40
whitequarkI think that thing worked by synchronizing with CRT scanline start signal?12:41
DocScrutinizer05right, that's how lightpens used to work12:41
DocScrutinizer05simply latch the address lines of the "framebuffer"12:42
whitequarkoh yes, that's much simpler12:42
whitequarkhow did it calibrate itself? I mean, there's afterglow of the phosphor12:43
whitequarkor is CRT actually a persistence-of-vision display?12:44
wpwraksample on rising edge ?12:44
whitequarkunlike e.g. oscilloscope, where it's "persistence-of-phosphor"12:44
whitequarkwpwrak: right.12:44
DocScrutinizer05I'm pretty sure ~50% of nuclear power plants used (or still use) SICOMP-M, and probably ~90% of powergrid infra does12:47
DocScrutinizer05those were dedicated process controller minicomputers12:48
DocScrutinizer05(yes, they were "mini2 by the time they were new)12:48
DocScrutinizer05traffic lights in Nuernberg/Fuerth/Erlangen been controlled by those critters, as well as Hbahn-dortmund and HBan-Duesseldorf12:50
whitequarkI'd take SICOMP-M over some Windows machine at any time of day12:50
whitequarkeven today, prolly12:50
DocScrutinizer05except for transport and energy cost ;-P12:51
wpwrakthen they replaced them. and thus the (lack of) punctuality of Deutsche Bahn became legend :)12:51
DocScrutinizer05(250kg, ~3kW)12:51
whitequarkwpwrak: something isn't punctual in germany? I refuse to believe :p12:52
wpwrak(250 kg) "real computer can't be carried away" ;-)12:52
DocScrutinizer05SIEMENS had an own transport branch only responsible for delivering those critters to the exact to the cm place where you needed them12:53
wpwrakwhitequark: apparently their train system has become a total mess after it got privatized12:53
DocScrutinizer05actually it's not privatized yet12:54
wpwrakfor punctuality, try the swiss. at train stations, there's a service announcement if a train has the temerity of being a minute late12:54
whitequarkwpwrak: does "total mess" mean "the timetable precision went from 30s to under 5min?" :)12:54
DocScrutinizer05it's preparing for going stock-exchange noted12:54
DocScrutinizer05and since nobody buys shares of a company that doesn't create revenue, they messed up stuff terribly during the last 10 or so years of preparing for that12:55
wpwrakwhitequark: more like cancellations, 30-60 minutes delays on commuter transports. trains breaking down, and so on12:56
whitequarkwpwrak: so like RZHD, then12:56
DocScrutinizer05or simply whole large stations *closed* for 2 weeks due to lack of personell12:56
DocScrutinizer05one dude got a flu12:57
DocScrutinizer05station closed12:57
wpwrakand apparently also in back-office functions. e.g., i heard a story that deutsche bahn sold tickets from .de to somewhere in austria or beyond. turns out that service was cancelled for a few weeks due to construction work. so people who traveled on those tickets ended up at the last station before the construction site with nowhere to go.12:58
wpwraknow the fun part: austria went out of its way to inform everybody. not only did they publish it, but they also send notifications to the other railways operators and i think they even did some ads to make sure really everybody knew. yet, ...12:59
DocScrutinizer05lol, usually they provide "busersatzverkehr"12:59
wpwrakdunno how they solved that. i think it was a major mountain pass or tunnel. so the detour may have been complicated.13:00
DocScrutinizer05and you don't say austrian "officials" really were eager to inform "piefkes", eh?13:00
wpwrakalso, they're probably not obliged to help you if you have a ticket for a service that doesn't exist :)13:01
DocScrutinizer05well, in austria I always feel like in GDR, really13:02
wpwrakin general or when on the train ?13:04
wpwrakalas, i can't find the story ... was a reader comment on telepolis, i think13:04
DocScrutinizer05when on the highway to get out of it as ASAP, and then stopping at one of the gas stations/restaurants13:07
DocScrutinizer05a donafion, a donafion!!13:09
nicksydneywpwrak: i need help in understanding this circuit http://www.electronicecircuits.com/electronic-circuits/555-negative-voltage-power-supply-circuit 13:12
DocScrutinizer05Service Temporarily Unavailable13:12
DocScrutinizer05503 Service Temporarily Unavailable error was encountered13:13
DocScrutinizer05hmm better13:13
wpwrakDocScrutinizer05: huh, why do you have to leave a highway in a panic ?13:13
DocScrutinizer05nicksydney: what's unclear?13:14
nicksydneyit says "When the output switches to ground, the C3 cap discharges through the D2 and charges the C4 capacitor to a negative voltage" ... what i'm bit confused is how C3 discharge through D2 is it through reverse bias ?13:14
wpwrak(donafion) you had me wonder for a moment whether there would be hordes of beggars at gas stations in austria these days :)13:14
DocScrutinizer05C3 gets charged (via D1), then when IC1:3 switches to GND level, it discharges via D213:15
DocScrutinizer05ooh, so it says exactly same as me13:15
DocScrutinizer05when C3 has positive charge on IC1:3 end and gets connnected to GND, then it discharges to ground creating negative voltage on D213:16
nicksydneyDocScrutinizer05: the discharging left me confused because in my mind D2 is a diode and the position of the D2 in that circuit should not allow current to flow from C3 to C4 via D2 ?13:16
DocScrutinizer05well, that's exactly why it creates *negative* output voltage13:17
DocScrutinizer05think of it like a tiny gnome with a mini rechargable battery charging it at V+ and then moving it to C4 to charge C4 with it, with inverted voltage with rspect to GND13:18
nicksydneylet me see if i get this right in my head....when PIN 3 is OFF  because C3 is charged the current travels to D1 to GND while at the same time it 'pulls' current via D2 to GND which allow current to flow through C4 ? does that make sense ?13:20
DocScrutinizer05nope, not much sense13:21
larscnicksydney: it want's to get to a equilibrium so it basically moves some of the negative charge at c3 to c413:21
nicksydneyok let's take one baby step at at time......13:23
larscyou can basically ignore everything except of C3 and C4 of the circuit13:23
DocScrutinizer05nicksydney: http://wstaw.org/m/2014/04/21/plasma-desktoptH6541.png13:23
DocScrutinizer05turn around the two diodes and it still works similar, just with negative output voltage13:24
DocScrutinizer05nicksydney: you might have missed: NE555 is an oscilator that constantly switches pin3 between V+ and GND13:25
nicksydneylarsc: if you put it that way..that makes more sense to me...but since D2 is in the picture I get lost again13:25
larscimagine the charges to be like this: 5 |C3| -5 --- <|D2| --- 0 |C3| 013:25
larscnow you change the 5 on the left side to -513:25
DocScrutinizer05BZZ wrong! GND13:26
DocScrutinizer05I guess what nicksydney is missing is the dynamics in the system, it oscilates13:27
larscyou get something like this -5 |C3| -2.5 --- <|D2| --- -2.5 |C3| 013:27
DocScrutinizer05now I bet everything is claer as vacuum, larsc ;-)13:27
nicksydneynow i'm more lost :(13:27
DocScrutinizer05thought as much ;-)13:28
DocScrutinizer05ignore all that, think of a pendulum and look at http://wstaw.org/m/2014/04/21/plasma-desktoptH6541.png13:28
nicksydneyok...this frickin' D2 is what confuse the hell out of me...the theory of D2 (diode) is it should conduct current in the schematics from right to left from -V it should travel to D1 ?13:28
DocScrutinizer05that tiny picture shows the two phases of the oscilation process13:29
DocScrutinizer05it should travel from C4 through D1 and NE555 to GND13:31
DocScrutinizer05driven by charge of C313:31
DocScrutinizer05after C3 has handed over its charge to C$ via D2, the NE555 switches to other state and connects C3 to V+ again, so it charges again via v+ -> NE555:3 -> *C3* -> D1 -> GND13:33
DocScrutinizer05when it's charged, NE555:3 switches to GND again13:33
larscnicksydney: are you clear on what charge is?13:34
DocScrutinizer05so C4 -> D2 -> *C3* -> NE555:3 -> GND13:34
DocScrutinizer05NOOOO! :-)13:34
nicksydneyi draw up the current (1) and (2) 13:35
nicksydneyDocScrutinizer05: http://wstaw.org/m/2014/04/21/plasma-desktoptH6541.png this one shows that current does not flow via diode ... am i reading it correctly ?13:35
DocScrutinizer05pin 3 never is "off" it's either connected to V+ or to GND13:35
nicksydneyDocScrutinizer05: sorry...it's GND when i say oFF :)13:36
DocScrutinizer05this is an important difference though13:36
DocScrutinizer05since current flows via D2 and C3 to GND13:36
DocScrutinizer05C4 -> D2 -> *C3* -> NE555:3 -> GND13:37
DocScrutinizer05actually lemme augment that13:38
DocScrutinizer05GND -> C4 -> D2 -> *C3* -> NE555:3 -> GND13:38
nicksydneyDocScrutinizer05: "so C4 -> D2 -> *C3* -> NE555:3 -> GND" ... this means the even though it pass D2 and C3 no current flow through D1 ?13:38
DocScrutinizer05current flows *either* through D1, *or* D2, for phase1 resp phase213:39
DocScrutinizer05V+ -> NE555:3 -> *C3* -> D1 -> GND  **OR**  GND -> C4 -> D2 -> *C3* -> NE555:3 -> GND13:41
nicksydneymuch better :)13:41
nicksydneybut now i'm lost why it does not travel to D1 when "GND -> C4 -> D2 -> *C3* -> NE555:3 -> GND"13:42
DocScrutinizer05_______ C3 charges _________________*OR*_____________C3 DIScharges, charging C413:42
larscbecause the potential is lower at C3 then at GND13:42
larscthe electrons don't want to move back to gnd13:43
nicksydneylarsc: correct me ...so C3 at that stage is minus which is lower than GND ?13:43
larscthat's why it is called -V ;)13:43
DocScrutinizer05it's minus on right end and positive on left end13:43
DocScrutinizer05since we previously charged it that way13:44
nicksydneythat's because the C3 is positioned with the plus near PIN 3 and minus on the other side so that's why it becomes lower than GND ?13:44
DocScrutinizer05V+ -> NE555:3 -> *+C3-* -> D1 -> GND  **OR**  GND -> +C4- -> D2 -> *-C3+* -> NE555:3 -> GND13:45
larscthe plus and the minus on the capacitor don't really matter for the theory behind this13:45
DocScrutinizer05well, somehow it does, but it's not what's meant by the schematics sign13:46
nicksydneyinteresting...so C3 when it's V+ is +C3- and then it's GND it become -C3+ 13:46
larsclets go through this step by step13:47
larscinitially the system is uncharged13:47
DocScrutinizer05V+ -> NE555:3 -> *+C3-* -> D1 -> GND  **OR**  GND <- +*C3- <- D2 -C4+ <- GND13:47
larscthen you apply a positive voltage on the left side of C313:47
larscthis creates a force and will move electrons from GND through D1 to the right side of C313:48
DocScrutinizer05V+ -> NE555:3 -> *+C3-* -> D1 -> GND  **OR**  GND <- NE555:3 <- +*C3- <- D2 -C4+ <- GND13:48
larscnow you have a negative charge on the right side of D313:48
larscclear so far?13:48
larscnow you connect GND to the left side of C313:49
larscwhich means you'll have a negative charge on both sides of C313:49
larscwhich means they'll create a opposing force13:50
larscwhich works on the left side of C313:50
larscright side13:50
wpwrakfound the train story :) here is the report about the problem: http://www.heise.de/tp/foren/S-Noch-ne-Bahn-Geschichte/forum-273657/msg-24689710/read/13:50
DocScrutinizer05HAH, very tricky explanation13:50
larscnow the electrons can't move back through D113:51
wpwrakand here's some background about what they did to warn prospective travelers and other railway operators: http://www.heise.de/tp/foren/S-Re-Noch-ne-Bahn-Geschichte/forum-273657/msg-24691386/read/13:51
larscbut they move through D213:51
larscwhich they will13:51
larscnow C4 was previously uncharged13:51
larscsince you are pushing electrons onto the top side there will be a negative charge13:52
larscthis will continue until the forces created by the charges on C3 and C4 are in equilibirum13:52
nicksydney"since you are pushing electrons onto the top side there will be a negative charge" top side of C4 ?13:52
DocScrutinizer05make electrons -> holes, and I agree ;-)13:52
larscnicksydney: top = connected to D213:53
DocScrutinizer05ooh, nope13:53
larscnicksydney: and if you switch fast enough between GND and VCC on C3 you are able to produce a constant current on -V13:54
DocScrutinizer05nicksydney: yes, exactly. electrons get pushed to top of C4 by C3, via D213:54
larscif you only switch once you'll have a negative potential on -V13:56
nicksydneyi see...that makes it easier....so the correct flow is like what DocScrutinizer05 mentioned... V+ -> NE555:3 -> *+C3-* -> D1 -> GND  **OR**  GND <- NE555:3 <- +*C3- <- D2 -C4+ <- GND ?13:56
larscbut the potential will discharge as soon as you connect e.g. GND to -V13:56
DocScrutinizer05nicksydney: note that my arrows (" <- ") are technical direction from + to -, not physical direction of electrons (from - to +)13:58
DocScrutinizer05this is consistent with all usual schamtics symbols13:58
nicksydneyDocScrutinizer05: understood14:00
nicksydneyso pretty much if i naively understand the whole thing is like a push and pull scenario14:00
nicksydneyas current flows towards the least resistance14:00
DocScrutinizer05yes, exactly14:00
larscto understand this you need to know what voltage, current and charge is and what their relationship is14:01
nicksydneylarsc: i do understand that part the part that something confuses me is to understand where flows to what side....but now if i think of it as pull and push that makes it easier to understand14:01
larscyea, I guess you can think of it as push and pull with D1 and D2 being valves14:02
larscfirst you open D1 and close D214:02
larscthen pull stuff in14:02
larscthen close D1 and open D214:02
larscand push stuff out14:02
DocScrutinizer05hmm, for physical direction that's correct14:03
DocScrutinizer05for technical direction you swap push and pull14:03
nicksydneyi kept on thinking that because D1 and D2 is a diode it has a breakdown voltage property which i think will not be broken as the voltage will not be that high enough 14:03
larscDocScrutinizer05: you first pull nothing in and then push nothing out ;)14:04
nicksydneysorry i meant "Reverse Voltage "14:04
DocScrutinizer05less than nothing14:04
larscnicksydney: think of them as ideal diodes for this example14:04
DocScrutinizer05actually electrons which are negative14:04
DocScrutinizer05for technical pragma you push a lack of electrons out, then pull a lack of electrons in and down to GND14:05
DocScrutinizer05as seen from output of 55514:06
nicksydneyafter understanding this circuit is it wrong for me to think when reading schematics that current can flow from either direction of + and GND ?14:06
DocScrutinizer05when you pull in the lack of electrons from C3, there will be more electrons on left side of C3, making the electrons on right side move to C414:07
DocScrutinizer05nicksydney: you're better off thinking about lack of electrons for reading schematics, so called "holes"14:08
DocScrutinizer05it's actually those holes that move14:08
DocScrutinizer05and they move the direction of the arrows in the symbols14:08
DocScrutinizer05and from + to -14:09
nicksydneyDocScrutinizer05: "when you pull in the lack of electrons from C3, there will be more electrons on left side of C3, making the electrons on right side move to C4" this is when PIN3 is V+ ?14:09
DocScrutinizer05no, this is when pin3 is connected to GND14:09
nicksydneyDocScrutinizer05: so this is like what larsc was saying it repels14:10
DocScrutinizer05but I start getting confused by this comnstant switching in our convo between technical and physical pragma14:11
larscphysical makes this so much easier ;)14:11
nicksydney:) ... if you are confused than i'm 100x confused :)14:11
DocScrutinizer05every sane electrician tells you that current flows from plus to minus, while they all know electrons move the opposite direction14:12
DocScrutinizer05so current is "holes moving"14:12
DocScrutinizer05a hole is a lack of an electron where an electron could be but isn't14:13
DocScrutinizer05those holes move from plus to minus14:14
DocScrutinizer05and are commonly called electric current14:14
larscthe thing is that you have almost infinite holes14:14
DocScrutinizer05larsc: I don't care14:14
DocScrutinizer05neither soes nicksydney14:14
DocScrutinizer05when I explain my water piping in my house, I don't need to consider water molecules pushing each other around14:15
DocScrutinizer05same for gas pipes14:15
nicksydneywhen i compare this circuit with other 555 circuit that uses capacitor the position of the capacitor (+/-) is what determine the negative voltage...if it is not positioned correctly it will not get negative voltage14:17
larscto understand how a charge pump work you can safely ignore the (+/-) signs on the capacitor and assume that it is an ideal capacitor14:18
DocScrutinizer05when it's not positioned correctly, it will break - when it's a polarized capacitor. There are capacitors that have no polirization and thus no + and - side, yet they will work all the same for C3 in this circuit14:19
larscthe + sign is connected to the side which has the bigger charge, this doesn't mean that the plus side acutally as a positive charge14:20
nicksydneyso this kind of caps http://gaussmarkov.net/parts/capacitors/mylar_caps.png will work also  ?14:20
DocScrutinizer05to get positive instead of negative output voltage, you simply revert D1 and D214:20
DocScrutinizer05sure they will work14:20
nicksydneyahhh ok....so the D1 and D2 is what determine the movement what voltage we want to get14:21
larscDocScrutinizer05: and reverse C4 ;)14:21
nicksydneylike this http://postimg.org/image/6f15htqbv/14:22
larscand now you explain why this creates a psotive voltage14:24
DocScrutinizer05larsc: minor issue14:25
nicksydneylet me try....taking into consideration that the caps are not polarised....when +V the current push to D2 -> C414:25
DocScrutinizer05actually depending on type, the circuit prolly will work for quite a while until C4 breaks14:25
wpwraki'd draw two circuits: one with IC1.3 = H, one with IC1.3 = L. only include the components that have significant current (and ignore the left side of the 555)14:25
wpwrakwell, and C5 ;-)14:25
DocScrutinizer05rrrright ;-P14:26
DocScrutinizer05you're better of to "use" non-polarized caps in your educational circuits14:26
DocScrutinizer05polarization of a cap is a negligible property for understanding circuits14:27
nicksydneyand when PIN3 is GND the current ... hmm ... bit lost here14:27
larscnicksydney: try to draw charges on the caps14:27
DocScrutinizer05then it simply shorts C3 to discharge it again14:27
larsc0, no charge, +10 positive charge, -10 negative charge14:28
larscand then go step by step14:28
larscstart with pin3 high-z14:29
nicksydneyahh yes larsc...when PIN3 is GND is goes from D1 to C3 as the left side of C3 will be lower 14:29
wpwrakdraw with IC1.3 = +5 V, think how the circuit will stabilize. indicate charges. then redraw with IC1.3 = GND.14:29
wpwrakfor visualization, you could imagine a little robot arm moving the C3 up and down. "up" is positive voltage, "down" is negative.14:30
larscand think of GND as -infinity charge and VCC +infinity charge14:30
DocScrutinizer05larsc: negative charge in respect to what?14:30
larscDocScrutinizer05: everything14:31
DocScrutinizer05larsc: you're really making it pretty hard for nicksydney14:31
nicksydneylike this .. http://postimg.org/image/xh55fpo6v/44004d37/14:31
wpwrakwith IC1.3 = 5 V, the cap is "up", standing on the 0 V line, and its upper side having a positive voltage. then the robot pushes it down. now the top is at 0 V and the bottom is now negative (since the charge in C3 preserves the voltage difference)14:31
nicksydneythe red line is when PIN3 +V and blue line when PIN3 GND14:32
DocScrutinizer05nicksydney: yes, that's pretty correct14:32
nicksydneyplaying with the +/- and thinking about GND rather than 0 make it easier for me :)14:33
DocScrutinizer05just C3 is *always* positive on left side, and negative on right side14:33
wpwrakhmm, with the reversed diodes it gets weird ;-)14:33
DocScrutinizer05unless you redefine V+ as GND, dunno what you're doing there14:33
wpwraki suppose we're now in the domain of metaelectonics, just as there are metaphysics ;-)14:34
nicksydneyDocScrutinizer05: "just C3 is *always* positive on left side, and negative on right side" ... so that means when PIN3 is GND the current is not flowing because it is lower than GND ?14:34
DocScrutinizer05you could redefine V+ as V-, then it was a really useful circuit creating a positive output from a negative input supply, all with respect to GND14:34
wpwrakexcept that IC1 may resent that polarity reversal. whitequark, you're the expert in 555 cooking here. what do you say, will the black smoke come out ? :)14:36
DocScrutinizer05nicksydney: I tend to think of forces that make holes move. a capacitor pushes away the holes on the + end, and pulls holes in on the - end14:36
DocScrutinizer05when 555 connects pin3 to GND, then C3 is the only force in the circuit making holes move, aka creating electric current14:36
wpwraki kinda doubt that considering quantum states makes it really clearer ;-)14:36
nicksydneywpwrak: any picture :) .. i'm more visual :)14:38
DocScrutinizer05i kinda doubt that funny comments make it any clearer14:39
nicksydneyDocScrutinizer05: " a capacitor pushes away the holes on the + end, and pulls holes in on the - end"...so in the context of C3 how is that applied ?14:39
DocScrutinizer05a "hole" has nothing to do with quantum states14:39
nicksydneyon another note...forgot to ask...what is C5 used for ?14:40
DocScrutinizer05nicksydney: sorry, I have no more time left over to antagonize the confusion introduced by the other guys14:40
DocScrutinizer05C5 is a buffer cap vor V+14:41
DocScrutinizer05for educational purposes14:41
nicksydneyso in case with my last diagram seems it's not needed correct ?14:41
DocScrutinizer05it's never needed until you find your actual power supply for V+ is not ideal14:42
nicksydneywhen you say "buffer cap" does that mean it is used to make sure that the V+ is stable enough ?14:43
DocScrutinizer05and even then the circuit will for sure work without C5, maybe a bit less smooth14:43
nicksydneyok got it14:43
DocScrutinizer05sorry, I have another 3 minutes, then afk14:44
nicksydneycool.....thanks for the help DocScrutinizer05 it make sense and i understand the circuit 14:44
DocScrutinizer05wpwrak: (smoke) sure it will explode14:44
DocScrutinizer05nicksydney: yw14:44
DocScrutinizer05wpwrak: ...unless somebody created an anti-555 I haven't heard of yet14:45
DocScrutinizer05for a transistor it would be easier, you just use a PNP instead of NPN type. I don't think same thing exists for NE55514:46
DocScrutinizer05nicksydney: ((so in the context of C3 how is that applied ?)) when your capacitor got charged then it#s + on left side and - on right side. When NE555 coonects pin3 to GND, the holes move from C3-left via ne555 to GND and from GND via D1 to C3-right until C3 has no more charge left over14:49
nicksydneyin case if anybody is doing any work with TFT i'm tested and used the library from https://github.com/adafruit/Adafruit_RA8875 with this display http://www.buydisplay.com/default/4-3-tft-lcd-display-module-controller-board-w-serial-spi-i2c-mcu 14:49
wpwrak(picture) here we go: http://downloads.qi-hardware.com/people/werner/tmp/chg.pdf14:50
nicksydney"i'm tested" ==> "i've tested" :)14:50
nicksydneyDocScrutinizer05: right ... need to remember to use that analogy to complement with using GND analogy14:52
DocScrutinizer05when Ne555 connects pin3 to V+, the holes move from V+ via Ne555 into C3 and - while charging C3, move on from C3 via D2 to C4, through C4 (charging it) and to GND. This stops when the sum of forces created by C3 and C4 charges is identical to the force of V+14:52
wpwrak(pic) note that the charge is the same in both configurations. therefore, the voltage difference on the C3 remains the same14:53
DocScrutinizer05now replace "force" with "voltage", and "moving holes" with "electric current" and you sound like a true EE14:53
wpwrakwell, using "charge" loosely here14:53
DocScrutinizer05that's a nice diagram14:54
wpwrakah, with one bug. fixing ...14:54
DocScrutinizer05cya l8r14:55
nicksydneywpwrak: this makes it easier for me http://postimg.org/image/v9lso8zkp/9496e600/ :)14:55
nicksydneyDocScrutinizer05: cya14:55
sb0what's the actual rectanglesize syntax in qcad?14:56
wpwraknow it's better. (the top of D2 is also (almost) -5 V)14:57
sb0all this stupid tool tells me is "You may change the number / coordinate format in the application preferences."14:57
sb0whenever I try to use that command14:57
sb0and does nothing else14:57
wpwrakqcad - for when life just isn't painful enough :)14:58
sb0what cad tool do you recommend?14:58
wpwrakfor 2D ? fped14:59
sb0and I can generate dxf files to feed into cambam from that?14:59
wpwrakmaybe unless you need very fancy geometric operations. but then, you can do even that in fped, with trigonometic functions14:59
wpwrakit can output gnuplot. so that's easy to convert to anything15:00
wpwraknow .. what's cambam ...15:00
sb0cnc software15:00
wpwrakwindoz, yuck15:01
sb0windows is a small problem compared to how painful mech design is in general15:02
wpwrakyou could write a little gcode or dxf output generator for cameo :) cameo is my tool for all sorts of toolpath manipulations15:02
wpwrake.g., cameo does tool offsetting and such15:02
larsctook me a while, but I still think that explaining it with charges is easier http://postimg.org/image/8vdh9myzh/15:05
wpwrakthe numbers are fascinatingly confusing ;-)15:09
larscI find this so much clearer15:10
wpwrakGND = -100, C3(-) = -5,  hmm :)15:11
DocScrutinizer05larsc: sorry to say, but your idea of charges seems flawed. it lacks any refrence level, there's no such thing like absolute charge in one point without any refrence point to measure that charge against15:11
DocScrutinizer05thus you expplaining that concept to a newbe will confuse the living hell out of them15:13
larscDocScrutinizer05: charge is absolute15:13
larscvoltage is relative15:13
DocScrutinizer05check the unit15:14
larscDocScrutinizer05: here for you to read http://en.wikipedia.org/wiki/Coulomb15:15
DocScrutinizer05charge is defined as the difference of electron poplation density betwee TWO objects15:16
sb0DocScrutinizer05, no, it's not15:16
DocScrutinizer05yes it si15:16
Action: wpwrak gets the popcorn and the beer :)15:16
sb0DocScrutinizer05, what's the charge of an electron?15:16
wpwrak1 q :)15:18
DocScrutinizer05sb0: exactly, you are completely confused15:18
DocScrutinizer05sb0: how much electrons may flow beween an electron and no electron?15:18
DocScrutinizer05how many, even15:19
wpwrakall of them ? :)15:19
sb0electrons are attracted by other charges15:19
sb0or repeled15:19
sb0depending on the sign of that charge15:19
DocScrutinizer05yes, so the charge is always defined as "all the charge difference between tow objects"15:19
sb0an electron in vacuum will keep going at its initial speed15:19
larscI think the definition of current would be quite funny if charge was relative15:19
DocScrutinizer05for singel objects, refence is "earth"15:20
sb0but to change that speed, you need to use other charges15:20
sb0or you can bend it with a magnetic field, if the initial speed is not null15:20
DocScrutinizer05good luck with getting your stuff sorted! tip: there's a difference between electron charge and battery charge15:21
sb0the charge in capacitors is actually the same as electron charges15:21
DocScrutinizer05yeah sure, if you short both electrodes and charge the whole capacitor VS EARTH15:22
sb0one farad is one coulomb per volt15:22
DocScrutinizer05and volt is what?15:22
larscdifference of charge15:22
DocScrutinizer05a singlur value15:22
DocScrutinizer05difference between a single object=15:23
DocScrutinizer05CYA, for good15:23
sb0nope, volt are the integration of electric fields generated by charged objects15:23
wpwraki wonder how long until you guys discover a new branch of physics :)15:24
DocScrutinizer05complete nonsesne15:24
wpwrakand i think it would help to clarify issues if you could express all this in terms of M-theory, paying special attention to the higher dimensions :)15:25
DocScrutinizer05the charge of a single object has nothing to do with the number of electrons on all atoms of that object, it is basically the differnce of electron density in that object IN REFERENCE TO A NORMAL15:26
sb0"equal to the potential difference between two parallel, infinite planes spaced 1 meter apart that create an electric field of 1 newton per coulomb."15:26
DocScrutinizer05and volt gets measured between TWO points15:26
sb0yes, absolutely15:26
sb0because it's an integral15:26
sb0of the electric field15:27
sb0and you integrate between two points15:27
DocScrutinizer05byebye, have fun with your math! ;-P15:27
sb0and the electric field is approximated to zero in a conductor, which is why you can measure voltage between any points on conductors15:27
sb0the charge of an object is q*(number of protons - number of electrons)15:29
sb0of course, a strongly charged object will tend to send its electrons or capture some elsewhere, in the forms of arcs, etc. :)15:30
whitequarkI wonder how you ever get anything done while entirely ignoring the math underneath. seems absurd15:30
larscif you say that charge is relative then you must also say that any number is relative ;)15:32
larsc1 is only 1 relative to 015:32
larscrelative to -1 on the other hand it is 215:32
sb0wpwrak, let's stick to classical 1860s physics for now :)15:33
larscor if we want to stay with physicis it's like saying that I can say that this stick is 1 meter long without saying relative to what it is one meter long15:37
sb0larsc, and yes, when there is a difference of potential, there is usually a difference of charge, the coefficient between the two being capacitance15:37
sb0(the RF case becoming significantly more complicated)15:37
DocScrutinizer51sure you can integrate the elctrical field of every arbitrary object from 0 to infinite, which is the definition of absolute charge of an electron15:52
DocScrutinizer51sure you can integrate the elctrical field of every arbitrary object from 0 to infinite, which is the definition of absolute charge of an electron. But for EE purposes this physical approaxh is oversophisticated to the idiocy16:05
DocScrutinizer51and actually pretty impossible to execute in reality, not even aproximately, since you always need to take into account the offset from charge of GBD16:07
larsccharge is still absolute though, no matter how hard you try16:09
DocScrutinizer51for any practical purposes charge is considered the *difference* of 'electron pressure' between two objects16:09
ysionneauisn't that the Voltage?16:10
DocScrutinizer51and for a capacitor juggling with the physical model of unary charges is nonsensival BS16:10
DocScrutinizer51ysionneau: right, charge is the capacity of that pressure diff16:11
Action: ysionneau doesn't understand16:12
Action: DocScrutinizer51 waits for an explanation of transistor using quantum physics rules16:12
DocScrutinizer51prolly you'll define the transistors amplification via quantum probabilities then16:13
DocScrutinizer51which most likely is basically correct16:14
larscseriously it doesn't matter on which layer of abstraction you are16:14
larsccharge is absolute16:14
larscthat's the very definition of charge16:15
larscthe same way that length is absolute16:15
ysionneauI think that in all my physics lessons I've been told an absolute definition of "the charge of an object"16:16
ysionneaubut I guess DocScrutinizer51  wants to say that in some practical cases you can just add or remove an offset to charge and you have the correct calculus16:17
ysionneaulike saying "from now on, +5V is GND"16:17
whitequarkI think I've just discovered the EE equivalent of a JavaScript programmer first encountering monads16:17
ysionneauand then 10V becomes 5V16:17
Action: whitequark fetches popcorn16:17
wpwraknothing to drink ? well, i guess in russia it would be considered a cultural fauxpas to have beer with the popcorn16:19
larscI'm assuming that I'm the javascript programmer in this16:22
DocScrutinizer51honestly, is this #Qi-hw or #Psi-physics?16:25
larscwell you started it ;)16:35
sb0ysionneau, no you cannot add or remove an offset from charges. if I have an object with 1 coulomb of charge in front of me, I will experience a certain force. if the charge is set to 2 coulomb, the force doubles.16:37
sb0in most electrical circuits, those forces are so small you don't feel them16:38
sb0(the electrons in the circuit, however, do - and that's what drives them)16:39
sb0but when you have static electricity on something and it attracts your hair, this is a human-sized example of a mechanical force caused by electrical charges16:39
ysionneauok, I should go back to my old lessons then :)17:00
ysionneauso much to learn and so few time to practice (to remember) ...17:01
DocScrutinizer05((well you started it )) actually nope, I didn't use physical pragma for direction of electrical current, neither did I introduce any concept of absolte electrical field aka charge of objects17:05
DocScrutinizer05rather I hat a hard time to mitigate the confusion you caused in nicksydney with that17:06
DocScrutinizer05concepts of theoretical physics are vastly useless for EE17:06
DocScrutinizer05actually when you try to explain a trabsistor via theoretical phyiscs, odds are you find out it can't work at all17:08
DocScrutinizer05transistor even17:08
DocScrutinizer05you'll find that computers aren't determinaistic machines. Heck not even transistors are17:09
DocScrutinizer05then you start investigating and learning more about all that, and finally you realize that a pot with water placed on your stove on fire could actually freeze17:11
larscyou said that I can't say that an object has a charge without saying relative to what other object that charge is, this is what started the discussion17:11
DocScrutinizer05which is true - for any EE purpose17:12
DocScrutinizer05EE give no flying F about absolute charge as defined in theoretical phyiscs17:13
DocScrutinizer05paricularly since you have no damn meaning to probe it17:13
DocScrutinizer05well, that's not completely true either, but sufficently close to reality17:14
DocScrutinizer05anyway when an EE talks about charge, they mean what you call capacity17:15
DocScrutinizer05while when they talk about capacity, they mean what you might call absolute maximum capacity17:16
DocScrutinizer05e.g a battery may have a capacity of 1500mAh and a current charge of 66% aka 1000mAh17:17
DocScrutinizer05what you call "charge" is irrelevant in EE17:17
Action: ysionneau mixed up capacity and capacitance17:17
DocScrutinizer05except for electrostatic charge you wanna get rid of, and even that is basically what you'd call "capacity of object ves GND"17:18
larscso the charge in charge put really means charge as in percentage?17:18
DocScrutinizer05no, in a charge pump it's actually elementary charges, this is the proverbial exception from rule17:19
DocScrutinizer05you could as well call it electron pump17:20
larscand it didn't occur to you that when talking about charge pumps I'm using the term charge in the same sense as in charge pump?17:21
DocScrutinizer05it's not like EE didn't know apart electrons from technical current direction17:22
DocScrutinizer05it didn't occur to you that a newbe like nicksydney can't use or even digest that theoretical physics lessons?17:22
DocScrutinizer05and claiming a capacitor had a negative charge on both sides when you connect one side to GND is definitely nonsense17:24
DocScrutinizer05nonsense that nukes the model of electronics, under construction in mind of a EE newbe17:25
larscpretty sure you need charges to explain a charge pump17:26
DocScrutinizer05whatever, good luck with your teacher's career17:26
larscif you had no concept of charges I don't see how you explain the current flow from C4 to C317:30
DocScrutinizer05in your model never any currentz flows from C4 to C3, since you used physical pragma for current direction17:31
sb0well, you can explain charge pumps with voltage and capacitors alone17:31
sb0especially if you make the assumption that capacitors fully charge and discharge in every cycle17:32
DocScrutinizer05for the rest, see what I did, what nicksydney answered, and what sb0 said17:32
sb0not with much detail, but at least get the working principle of the thing17:32
larschow? (serious question, I have no idea)17:34
DocScrutinizer05see backscroll17:35
DocScrutinizer05you can even explain the whole shit with a hydrailic model17:35
larscbut in the hydraulic model you have charges in the form of hydraulic fluids17:36
sb0also, you can probe absolute charge. one way of doing it is to give the thing some speed and put it in a magnetic field. the curvature radius of the bend given by the magnetic field is proportional to the charge (divided by the mass).17:36
DocScrutinizer05no need to have the slightest idea of electrons and (physical filed )charge17:36
sb0inversely proportional actually17:36
DocScrutinizer05larsc: now that's ridiculous17:37
larscno that's the hydraulic model17:37
DocScrutinizer05in a closed hydaulic model you have no fields17:37
sb0another way of doing it is to use the forces created between charged objects17:37
DocScrutinizer05neither integrals over fields fronm 0 to infinite17:38
larscnobody every talked about that17:38
larscI think you are really confuse17:38
DocScrutinizer05ooh, so what been the definition of *your* charge, again? I forgot17:38
sb0DocScrutinizer05, how do you explain Paul traps?17:39
DocScrutinizer05indeed I am confused how you mix unary sizes into a strictly closed system17:39
sb0or mass spectrometers17:39
DocScrutinizer05sb0: how do you explain people's affinity to meaningless arguments?17:40
sb0I'm just trying to correct some wrong views about what electric charge and voltage are17:41
DocScrutinizer05and please tell me the mouser part number of the mass spectrometer component. Will it be SMD or thru hole wire?17:41
sb0electronic circuits operate on the same physics as mass spectrometers, there's no point in drawing a line17:42
DocScrutinizer05yeah, and all obeys general relativity17:42
DocScrutinizer05and quantum physics17:42
sb0we don't need to go that far, it's just classical electrostatic field theory for now17:43
sb0not even electromagnetism17:43
DocScrutinizer05maybe for you, I don't need any of that to explain how a charge pump electrical circuit works17:43
DocScrutinizer05since electrostatic fields are *absolutely* irrelevant for that17:44
sb0they are, that's what makes a capacitor work at a very basic level17:45
DocScrutinizer05that's an age old scientific principle called abstraction17:45
DocScrutinizer05you'd be surprised when I started to explain to you how capacitors *really* work, in real life17:46
sb0ok well17:46
sb0you feed 100mA to a 100uF capacitor for 100ms17:46
sb0initially discharged17:46
sb0what's the voltage across the capacitor after that?17:47
DocScrutinizer05you might find that electrical fields are maybe only a minor negligible effect in the whole story, particularly for electrolytic capacitors17:47
sb0do you agree that this is a valid EE problem?17:47
DocScrutinizer05what's the voltage you ask? first answer a question I have for you: how large is the capacitors capacitance after charging it like you said?17:48
sb0make it a bank of non-electrolytic capacitors if you wish17:48
DocScrutinizer05now if you answer "duh? 100uF, like I said" you already lost the game17:48
DocScrutinizer05no problem, fetch an arbitrary datasheet for X5R or X7R17:49
wpwrakkewl. the fight is still raging on ;-)17:49
DocScrutinizer05you still have no idea about the *capacitance* after charge, without that datasheet17:50
DocScrutinizer05so could we just consider a capacitor a blackbox and ideal please?17:50
sb0ok, well, do you agree it's still within, say, +/- 30% of 100uF?17:50
DocScrutinizer05at least for purpose of explaining a newbe how a chargepunp works?17:50
DocScrutinizer05and no17:51
DocScrutinizer05bich be as little as 30% of priginal value, aja +/- 70%17:51
DocScrutinizer05eh? s/bich/might/17:52
sb0ok, make it 70% if you wish, which sounds a bit large for high-quality non-electrolytic caps, but whatever17:52
sb0and I restate the problem:17:52
sb0you feed 100mA to a 100uF +/-70% capacitor for 100ms, initially discharged17:52
DocScrutinizer05and I resttae I'm afk, since this discussion leads nowhere17:52
sb0what are the lower and upper bounds of the voltage reached after the charge?17:52
wpwrakin fact the truth is that there's no physical basis for how capacitors work. they function completely by magic. and by a strange twist of fate, that magic just produces results that in almost every case appear indistinguishable from plausible-sounding physical principles :)17:52
DocScrutinizer05wpwrak: almost true ;-) But still just an argument to consider them a blackbox that doesn't need any explanation beyond F=As/V17:55
sb0DocScrutinizer05, is that a valid EE problem now?17:55
DocScrutinizer05for educational purposes17:55
sb0DocScrutinizer05, and how do you solve it without the concept of charge?17:55
DocScrutinizer05then forget about it, partucularly forget about electrostatic fields, and get the datasheets17:56
sb0and, hmm, what is As? :-)17:57
larscmagic, like wpwrak said17:57
DocScrutinizer05since in datasheet you get diagrams for capacitance vs voltage and all such stuff17:58
DocScrutinizer05and your electrosttaic fields don't help you a angstrom there17:59
DocScrutinizer05they help you in physics classes to explain the *principle* of an ideal capacitor to pupils18:00
DocScrutinizer05but you don't need to understand *how* a capacitor works to understand a charge pump circuit18:00
sb0you can, actually, get pretty accurate theoretical results for those curves using that electrostatic field theory you hate so much and finite element analysis18:01
DocScrutinizer05you need to know that it kinda works similar like a battery and that's all, for this purpose18:01
DocScrutinizer05sb0: so what? explain to nicksydney what's piezo electrical effect?18:02
DocScrutinizer05to transport the concept of a charge punp circuit to him?18:02
DocScrutinizer05honestly, this is one of the most moot and nonsensical discussions I even *seen* during last 12 months. I can't believe I still *contribute* to it18:03
sb0I'm merely answering your incorrect claim that "charge is defined as the difference of electron poplation density betwee TWO objects", and similar ones18:03
DocScrutinizer05A. F. K.18:03
larscI suppose you can explain what a charge pump does without capacitors, but not how it dos it18:04
DocScrutinizer05and I'm sure you canNOT explain what a chargepump does nor how it does it. We all seen the proof18:05
larscwell I suppose than we disagree ;)18:06
DocScrutinizer05(([2014-04-21 Mon 19:46:55] <sb0> initially discharged)) how the hell do you dischage a capacitor, when we assume *your* definition of charge?18:12
sb0equal charge on both plates, usually zero18:13
DocScrutinizer05see what I mean?18:13
DocScrutinizer05this discussion is mere sophism18:13
DocScrutinizer05from your side18:13
DocScrutinizer05and AFK agin, since this doesn't tend to become any more meaningful a discussion, no matter how long we continue this torture18:14
sb0no. if it's non-zero, then the capacitor starts doing weird things, like attracting external objects18:14
sb0and yes, there is attraction between the plates of a charged capacitor18:14
sb0but that's between the plates, the net charge of a capacitor is (usually) zero, as one plate will have a positive charge and the other one the same but negated18:15
sb0in virtually all practical cases, the charges on the plates of a discharged capacitor are zero on both18:16
sb0when you are charging a capacitor, you are putting As charge on one plate, and removing As charge from the other18:19
DocScrutinizer05no, on absolutely all cases the "charge" of a capacitor (as in your definition of "charge") is exactly zero (plus/minus offset of globe earth reference), when one side is connected to GND18:19
DocScrutinizer05no matter how much charge of my definition it holds as potential difference between the plates18:20
sb0the earth isn't significantly electrically charged, otherwise other charged objects will be attracted or repelled by it18:20
larscif the charge is the same there is no potential difference18:20
DocScrutinizer05and that (electrical) potential diff is rarely a pure electrostatic field, usually it's magnitudes more complex18:21
DocScrutinizer05sb0: aha! and how did you test that?18:21
DocScrutinizer05actually I think you're massively wrong here18:22
DocScrutinizer05and that doesn't even take into account local variations of electrostatic field created by meteorological effects18:23
DocScrutinizer05whatever, EE cncept of charge is massively different to theoretical physic's concept of charge. See "charging a battery"18:24
DocScrutinizer05and you're free to create a zillion bizarre examples from this messup of namespaces, I don't care18:25
larscI think EE must have changed since you took it18:25
sb0DocScrutinizer05, CRTs test it. the charged beam of electrons isn't attracted or repelled by the earth. you can turn a CRT around and the picture will stay the same.18:25
larscthe first thing we learned is what charge in sense of Q is18:25
larscthen what I and V are18:26
DocScrutinizer05sb0: again massively false18:26
DocScrutinizer05sattelites can create a few Watt(!) of electrical power by simply pulling a few 100m of wire with them, so the wire will point radially in or out from center of orbital and happens to be center of earth roughly. Guess what makes this work. Do your conclusions what this means for electrostatic potential of earth18:30
sb0what closes the circuit?18:31
sb0do you get AC or DC?18:31
DocScrutinizer05err DC18:31
sb0so you connect anything to such a wire, and DC current will flow through it?18:32
DocScrutinizer05well, there's no such thing like an electrical open circuit, so the "ether" closes the circuit18:32
sb0let's say I connect a lamp, I connect one terminal to this wire, nothing on the other one, and it will light up?18:33
DocScrutinizer05no. the sattelite body is the other end18:33
DocScrutinizer05or a second wire pointing in opposite direction18:33
sb0how are the electrons flowing in there?18:33
sb0don't they accumulate in one end, then?18:34
DocScrutinizer05seems the escape on the other end like they came in on the first end18:34
larscfree energy for everybody, yeay!18:35
DocScrutinizer05sorry, I have no good sources to cite18:35
DocScrutinizer05larsc: look up, do you see that bright thing up there. Free energy for everybody is a reality since a 4-some billion years18:36
DocScrutinizer05guess what's the energy feeding aurora 18:36
DocScrutinizer05do you think somebody sponsors it?18:37
sb0initially, nuclear fusion in the sun, which isn't infinite18:37
DocScrutinizer05tzz. how's THAT finite7infinite relevant now?18:38
DocScrutinizer05you leave no opportunity to continue this execise in sophism, eh?18:38
larscwell the energy comes from the sun18:38
larscno the earth18:38
sb0is any argument that runs contrary to your opinions sophism?18:39
DocScrutinizer05is any argument you just can think of a good argument?18:39
sb0show it's bad then. and I'm really just explaining 1860s-level classical physics, not anything really fancy18:40
DocScrutinizer05I get bored and tired to be responsible for your monday evening entertainment18:40
DocScrutinizer05and you wonder why you fail in an argument with me when you revert to 1860 physics? LOL18:41
DocScrutinizer05for CRT: active compensation in color TV; shielded; + U forgot to estimate size of effect18:45
sb0active compensation? there's no feedback loop to control the position of the electron beam18:47
DocScrutinizer05are you sure? (this been a rethorical question)18:49
DocScrutinizer05also compensation != feedback18:49
DocScrutinizer05and thanks to better shielding and other improvements the compensation isn't needed since I guess mid of 80s18:50
sb0yes, put a magnet in front of a CRT, you can bend the picture (nb: this also fucks up colors and sticks as it magnetizes the internal grid, so don't try on a crt you care about)18:50
sb0of course, you can still argue that the magnet saturates the feedback system :-) oh well...18:50
sb0you can compute the expected deviation without feedback system them :-)18:51
DocScrutinizer05I told you conmpensation is not identicsl to feedback, oh my18:51
DocScrutinizer05honestly, I don't get paid for this torture18:51
sb0if it's not feedback but static compensation, then rotating the screen would change the picture in the presence of a strong electric field18:54
wpwrakkewl. it's STILL going on :) fascinating. let's see for how many more hours you can keep it up ;-)19:01
wpwraknicksydney: i think that was the most "productive" question ever posted on this channel :-)19:02
DocScrutinizer05just left us clueless how charging a battery is even possible when you consider what theoretical physics says about charge19:04
wpwrakcharging batteries ? just more witchcraft. just fire up your time machine, grab your cell phone, and hop back into the middle age. go to the market square and show people the cool things your phone can do. especially movies, voices, and take pictures. they'll probably burn you on the stake that very same day :)19:06
ysionneauwaaa the discussion is still going on :)19:27
ysionneaulot of reading tonight19:27
DocScrutinizer05>>demonstrate electric power generation<<20:06
DocScrutinizer05http://www.physics.sjsu.edu/becker/physics51/capacitors.htm  >>When a capacitor is being charged, negative charge is removed from one side of the capacitor and placed onto the other, leaving one side with a negative charge (-q) and the other side with a positive charge (+q). The net charge of the capacitor as a whole remains equal to zero.<<20:08
DocScrutinizer05>>[2014-04-21 Mon 15:49:44] <larsc> which means you'll have a negative charge on both sides of C3<< which means the capacitor actually HAS charge to "the universe" then. I wonder where from that charge comes, and how the heck it can build up on "left side" plate while that plate is said to be connected to GND at that very moment20:11
DocScrutinizer05s/capacitor actually/capacitor as a whole actually/20:12
DocScrutinizer05point made. bye. ETX20:15
sb0ah, dammit20:18
sb0current generation *in a plasma*20:18
sb0that plasma is what carries the electrons around20:18
DocScrutinizer05sure, what else20:19
DocScrutinizer05some form of ions or free electrons needs to be there to create a current20:19
sb0before you said that it worked just because of some wire pointed towards a supposed electric charge held by the earth. that's not how it works at all.20:19
DocScrutinizer05it is20:20
DocScrutinizer05since, if that field of ions was uniform, then why the heck would it create a current through a blind end wire?20:21
DocScrutinizer05also refer to very first 2orso sentences in http://www.meridian-int-res.com/Energy/ESMotors.pdf20:21
sb0the ionosphere is ionized by solar radiation, and this has little to do with the earth20:22
sb0and you can point wires towards electric charges as much as you want, you'll never get a DC current20:26
sb0only a transient spike of current20:27
sb0the earth is round20:28
DocScrutinizer05more blabla? nice!20:28
Action: DocScrutinizer05 feels like explaining relativity theory to a pupil, and getting blamed for lieing since that's "not complying to what Keppler said"20:30
DocScrutinizer05actually I expected "the earth is a disk"20:31
DocScrutinizer05"there can't be any satellites flying around it!"20:32
sb0heh, that satellite isn't exploiting some new effect. just plasma theory, which is based on charged particle dynamics in electric fields, which for some reason you seem to have a particular aversion for20:32
DocScrutinizer05bullshit, you have no idea what I#m telling you, not to think about you knowing what I might have an aversain against20:33
DocScrutinizer05and your idea of plasma theory is pretty cloudy, to be polite with you20:34
DocScrutinizer05and who said that effect is new? you should've noticed I picked docs from last century's 70s, to not shock you too much20:35
DocScrutinizer05anyway even you claim there's an "electric field" involved20:36
DocScrutinizer05which after all been all I wanted to provide evidence for20:37
DocScrutinizer05and now please find somebody else to educate you20:37
DocScrutinizer05I prooved that there's a really significant electric field on ground level of earth as well as in near-earth orbit. And thus I prooved you wrong on >>[2014-04-21 Mon 20:20:36] <sb0> the earth isn't significantly electrically charged, otherwise other charged objects will be attracted or repelled by it<<20:39
DocScrutinizer05at least on first half of it, sencond half is just too silly to pay attention to it20:40
sb0I knew about this electric field. "significantly" is the important word here.20:40
DocScrutinizer05whatever you say, troll20:41
DocScrutinizer0533V/m is significant in my book, particularly when we talk about whether or not there's *any* offset to absolute charge of terrestrial objects 20:44
whitequarkwow, you're STILL talking about this20:46
DocScrutinizer05a "discharged" object is NOT at zero, according to your definition. It's at zero *relative to GND* while its absolute charge is quite a bit biased by a field of 33v/m around whole earth, at ground level20:47
DocScrutinizer05and again, this absolute charge is completely totally irrelevant for any EE purpose. See http://www.physics.sjsu.edu/becker/physics51/capacitors.htm20:49
DocScrutinizer05since in EE we usually only care about relative charges. In case of a capacitor, relative one plate to the other related plate20:50
DocScrutinizer05and we asume the total outside charge according to your definition of the word "charge" as irrelevant and thus assume it's zero, while we know it isn't in reality20:51
wpwrakwhitequark: this month's IRC traffic will beat all records :)20:54
DocScrutinizer05thus, for EE the term "charge" is a relative (one in relation to the other) quantity20:55
DocScrutinizer05either (usually) between two moderately sized and often identical objects, or (in rare exceptional circumstances) object relative to earth20:57
DocScrutinizer05never ever we care about absolute charge (relative to infinity)20:57
whitequark"hardware hackers join here to discuss semantics, apparently endlessly"20:58
DocScrutinizer05some seem to do, yes20:59
whitequarkalso I would think that satellites would orbit the disk just fine, if you can keep it, well, in the form of disk20:59
whitequarkwhich is unlikely for all I know20:59
DocScrutinizer05even worse: they to by trying to support their point by incorrect assertions20:59
whitequarkafaik the only stable shape for relatively large solid bodies is sphere, in our universe20:59
DocScrutinizer05more or less. Only true for static (non-moving) objects21:00
whitequarkif it spins faster than is needed to make it but an oblong spheroid, then it will be torn in pieces21:00
DocScrutinizer05or more generally, for objects that don't see any acceleration of whatever form21:00
whitequarkhm, actually I think a static disk would be possible21:01
DocScrutinizer05hardly, even21:01
DocScrutinizer05depends on size21:01
DocScrutinizer05and maeterial constants like density and stability21:02
whitequarkeh. I should have went to school in engineering. I'd know sopromat21:02
whitequarkstrength of materials in english, apparently21:02
whitequarkthat's really one discipline I wish I knew, despite it requiring a ton of wonky math21:03
DocScrutinizer05I guess even the experts use stuff like finite elements in PC nowadays21:04
whitequarkah. sure, the actual calculations are all numeric21:05
whitequarkit's the understanding of concepts that matters21:05
DocScrutinizer05finite elements. lots of tiny triangles21:05
DocScrutinizer05no rocket science, just massive computation grunt thrown at it21:06
whitequarkmm, perhaps21:07
DocScrutinizer05http://en.wikipedia.org/wiki/File:Example_of_2D_mesh.png  http://en.wikipedia.org/wiki/Finite_element_method21:09
DocScrutinizer05the concept of "when does a triangle made of certain alu, of the size 1*1*1cm, tear apart (or fold in, depending)" is no problem of the "ton of wonky math" class21:14
DocScrutinizer05hald a dozen vector equations, roundabout same amount of limit checks21:15
whitequarkI see21:16
DocScrutinizer05then create your disc out of a zillion of those finite elements21:16
DocScrutinizer05and watch it break down21:17
DocScrutinizer05you prolly want to add a certain low percentage of random noise to positions and directions of the force vectors, to avoid singularities in your solution21:19
DocScrutinizer05since otherwise you probably could prove that you could put eiffel tower on its tip and it would neither fall nor break ;-)21:20
Action: whitequark snorts21:23
wpwrakso far, such a hypothesis would be perfectly consistent with experimental results21:24
whitequark"three moldavians placed bets on who will first cross MKAD [a highway around moscow]; only one survived"21:24
whitequark(source: http://www.zbulvar.ru/?c=news&id=46991)21:24
wpwrakthat looser21:25
DocScrutinizer05loser, please21:25
wpwrakyeah, right21:25
DocScrutinizer05(random) also never entering exact integer values like 0°, 90° and so on helps a lot. Eiffel tower will definitely fall when ground footprint square cm is not 0° in each direction, but maybe 0.001° tilt to east21:29
whitequarkI wonder if there would be some self-emergent chaos in the calculations, that seems likely21:30
whitequarkperhaps even from FP uncertainty21:30
whitequarkthe calculations are probably not fully isotropic21:30
DocScrutinizer05at least it's not guaranteed21:30
whitequarkit has to start with something21:31
whitequarknot guaranteed, definitely21:31
DocScrutinizer05I'd *guess* chaos could only emerge when you got feedbacks >1 somewhere in that whole batch of equations21:34
DocScrutinizer05after all FEA is usually static and not taking any dynamic effects into account21:35
DocScrutinizer05first approach at least21:37
DocScrutinizer05more sophisticated systems have feedback like elastic and even plastic deformation due to applied forces21:38
DocScrutinizer05depending on what to check, they might even have inertia and time in their equations21:38
DocScrutinizer05see weather forecast. And even those guys do microscopic random changes to their initial parameters to get the solution-space, rather than running same equation several times from same initial parameters and hoping for chaos to self-emerge21:40
nicksydneymorning/evening all22:43
nicksydneythe display used in this kind of product ( http://theruniverse.com/wp-content/uploads/2014/01/fitbit-one_black-burgundy-e1347847727188.jpeg )  is that a normal OLED display or a customised OLED ?22:55
nicksydneyWOW!..i just scrolled through the chat conversation and it's all beyond my understanding :).....i will keep it simple for myself as newbie like me prefer 1 explanation to make the brain think straight :)23:07
nicksydneylost of conversation when i was sleeping in the room :)23:08
nicksydneymade a summary of what i learned last night http://postimg.org/image/r3x23a94p/ 23:33
nicksydneyin case if some newbie like me comes here and want to learn what i've learnt :)23:33
nicksydneywhitequark: http://www.news.com.au/technology/science/amazing-new-video-shows-a-meteor-burning-up-in-the-sky-above-murmansk-russia/story-fnjwlcze-122689040392223:38
DocScrutinizer05nicksydney: (what you learned) looks fine, after it finally displays. Just I'd think "the whole process..." is actually correctly described for holes already (aka technical direction of current, + -> -). The *)footnote >>"holes" are push and pull around<< seems incorrect, at least for the above correct explanation23:59
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