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esaj last won the day on July 2 2017

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About esaj

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  1. esaj

    Uses for old still good battery packs?

    At least some (most?) older IPS's have BMSs built into the mainboard or some separate board inside the aluminum cooling case-thingie, and the newer King Songs (well, at least KS16S, might be also the other S's) have the MT60-set up, but many other wheels seem to use just XT60's (or some other connector), so as long as there's no other wiring running between the battery packs and the mainboard, and they use the same "16S" (16 cells in series, not KS16S) batteries, the only issue should be being able to get the packs to fit inside the wheel. Connectors can always be changed (of course take the "usual" precautions if you start to fiddle around with the batteries: )
  2. esaj

    Uses for old still good battery packs?

    The batteries contain 18650-cells (like @digitalkenny said above), so you could take them apart and use the cells. On their own, the voltage is too high for most devices that use something like 12, 9, 5 or 3.3V, but with suitable (high enough DC input voltage allowed) devices, they could be used as-is. Most wheels use XT60's, but KS16S switched to MT60's (if memory serves) and apparently uses the third line for some type of communication between the BMS and the mainboard, so likely wouldn't work just by connecting the red and black wire there, but should for other wheels using batteries with same voltage (67.2V max, 16 cells in series). XT60: MT60: There are motorcycle lights available that work up to 80V input, but I had one die on me during testing, so the quality of these ones might not bet that good: These things are really bright, the picture's taken in a fully lit room but the surroundings look dark because of the camera. Homemade flashlight using 2 x 18650's, I use this during the winter to take the dog out late at evening/night, 10-15 minutes of use per day, usually need to recharge only every 3-4 months (with <2000mAh cells): Not a very efficient solution, as it uses simple constant current source to keep the current in check, step-down switching would be much more efficient (so it would need to be recharged even more infrequently). Easiest way to use them is to produce heat
  3. esaj

    Ks16s 1.05 firmware is here

    Just when I was considering whether I actually should try to update... x)
  4. esaj


    Trying to keep this short: Not in this town, but in general it seems more riders are finding their way at least to the forums. Yes, not really long trips so far, but I commute on it daily now and sometimes take some longer laps. Nope, I'm considering selling the KS16B, that's why I rode it all the way to empty tonight (or until I couldn't stand the constant beeping that starts when the voltage drops to below 50V or so). Might have to leave it sitting turned on next evening, as it'll likely bounce back up a bit, then let it sit off for a while before charging & measuring the battery capacity. Always For the past few months, yeah, I'm building up parts list for an adjustable load (a project that I've meant to built for at least 1.5 years or so, never had proper cooling components and such) The printer too has mostly sat unused lately, I've also spent most of my PLA filament (something I need to order too) and left with a couple of kilos of ABS, which has been pain to print with. Usually my printing needs go hand in hand with the electronics projects, so kind of follows with the pause there... It's handy otherwise, but making any larger parts with it is sloooow (like 4+ hours print jobs) and sometimes it may need a few tries before getting things correct, so in addition to space, it also takes a lot of time to "find" the good settings. It's fun to watch though, well, maybe not for hours straight
  5. esaj


    The course was between September and December, I haven't really touched the robots since I've actually had those power supplies laying around since mid-February, just today got around to finally start figuring out what's wrong. Between there and now I haven't really done much anything.
  6. esaj


    That was a lot less dramatic than expected. Trying the faulty supply again, I could not get any voltage out from the outputs. I tried swapping the secondary board with connectors between the two units, but the working one was still working and the faulty one still didn't give out any voltage. Measuring around the outputs in both supplies, I found similar voltages with same settings on both units, all the way to the capacitor which (presumably at that point) was in parallel with the outputs. The most likely culprit was simply a bad contact at the output banana terminals. Most of the time was spent figuring out how to dismantle the front panel and the switches and boards attached to it so that I could get enough space to get to the terminals and then prying the nuts holding the board in place as I didn't have a suitable socket for a wrench and there wasn't much space. The board finally off: The banana terminals were simply connected by two screws on both sides of the board, pushing a lock washer against the traces. Over time, the contact has become worse, and when it originally dropped the voltage to near zero when I put any load on the outputs, the voltage was being dropped in the bad contacts. Apparently after that they didn't make any contact any more, as I didn't get readings from the output. I ended up simply soldering wires from the bananas and the middle connector (chassis ground) and put some foam plastic there to keep the board from making contact with anything. I then tested the supply with 100V idle, 50V / 0.1A load and 4V / 1A load (as I didn't have anything much more suitable in regards of power resistors or other load) and everything just worked. Also checked that the board or the parts near it don't get too hot to melt the foam plastic. While nothing near the foam got hot, some of the components do run pretty hot: Power resistor and a couple of transistors in the secondary board: Power resistors in the rectifying board: There's also a large TO-3 -packaged power transistor that sits against the chassis, but it never got higher than 40 degrees. Didn't really run the tests for very long either, something like 15 minutes each. I didn't take much pictures during the work (also I've noticed that the Cat S60's camera software, or maybe the camera itself, has horrible auto focus when trying to take close ups), but here's a couple that some people might find interesting: Like I said earlier, the supplies don't contain any SMD (surface mount) -components, and also very little in terms of integrated components (not much need really) and a lot of things are made with discretes, except the board running the 7-segment panel in the front showing voltage or current seems to contain more logic chips. The round components in the middle and to right are actually OP07- op-amps, and the one on the left is MC1741-opamp in a (nowadays) uncommon TO-99 package: I didn't try to reverse engineer the board really, since swapping them had no effect, so no need to look for a fault. The more (or at least slightly) interesting bit is the backside of the board: Back in the day, something like 70's and 80's I think, when PCB design and manufacturing was already more "industrial", small scale production runs and hobbyists still used boards that were drawn by (free) hand, sometimes directly to the film, then exposed the PCBs with UV and then etched and drilled them with their own hardware. It seems that these power supplies, while likely made in hundreds or thousands, were still too small scale (too costly) to make the boards in a PCB factory, or maybe they just had old school -designers who liked to design their boards by hand and the final boards are factory-made. Still looks a bit weird having accustomed to modern (usually) computer designed boards, and mind you that this is still an actual commercial product. You can find similar boards in lots of old devices dating to 70's and back, and some in newer products too. In DC/nothing really high frequency -stuff it doesn't really matter that much (to my knowledge) as long as safety distances for high voltage traces etc. are maintained. Now that I have a working (up to) 100V DC power supply with current limits, I can test stuff that's supposed to run off of wheel batteries (16S or 20S) without needing to use actual batteries. The originally working unit goes back to a friend that had bonked them from somewhere a while back, and dropped them off saying I can keep the faulty one if I can fix it
  7. esaj


    Nah, didn't go to electronics school or such, mostly just been busy & tired, and things got a bit hectic. I actually resigned from my job at one point, but then ended up taking a part-time contract. Not much been going on in the electronics-side, the last thing I did was this in early Feb for a company year kick-off costume-party: It's just a bunch of "chainable" RGB-LEDs (WS2818/"Neopixels") and a controller for them. I used some velcro strap to attach it around my arm, with the final version having the controller glued to the back of the board and power wires running under my shirt to a battery in my pocket... The board and the "faceplate" are milled, the black part in-between is 3d-printed. Not much been going on since, someone did ask me for some help with building a speedometer for their wheel, but don't know if he ever finished it. I did get a couple of 0-100V adjustable linear power supplies, although only one of them works: The non-functional one does power up, the display works and allows adjusting the voltage etc, but when any current is being pulled from the outputs, the voltage drops near to zero. Could be that the current limitation is broken and activates regardless of where the actual limit is set to? It does help to have the identical working unit, so I can compare voltages and such between them. The company who made these sometime in the 80's has been defunct since early 2000's, and there's no schematics available, so I have to do some reverse engineering to find out what's wrong with the other unit. There's a lot of wiring and 4 separate boards (+ large other single components) in these things, luckily they use just plain through hole (THT) -components and not really many integrated circuits, so poking around is easier than with highly integrated/SMD boads. Also the wiring is done very neatly and it seems most of the boards have contactors so it's possible to pull them out and put them back in. Still, it's not very fast to figure out things (and I haven't really even began yet) and I have to be careful because I'll have to power them up every now and then to measure voltages going up to 115V AC or more in there (around 230V AC at the input to the large toroidal transformer). Since I've so far been working around just with low voltage DC-stuff, it's a bit nerving Also, the large capacitors (the big black blobs attached by white zip ties) hold the charge after power down and need to be discharged safely before poking my hands in there or measuring resistances or continuities.
  8. http://www.1radwerkstatt.de/epages/80603321.sf/en_GB/?ObjectPath=/Shops/80603321/Categories/Category2 Tekevät mittatilauksena sellaiset että sopivat pyörään ja hyvälaatuisista kennoista ja BMS:istä. Jos tuolta päädyt tilaamaan, lähetä suoraan postia 1RadWerkstatt@gmx.de Sivuilla Jos Airwheeliin mahtuu vain yksi paketti (16S1P), saa sen kuitenkin 3500mAh kennoilla (luultavasti LG MJ1 https://lygte-info.dk/review/batteries2012/LG 18650 MJ1 3500mAh (Green) UK.html ), eli 210Wh. 1RadWerkstatt laskee akkujen kapasiteetin "oikeaoppisesti", sen takia esim. 210Wh kohdalla lukee 207Wh, 840Wh on 828Wh etc. Pyörien markkinointiosastot käyttävät pyöristettyä 60V -nimellisjännitettä kapasiteetin laskussa, nuo taas "oikeaa" 59.2V:tä (3.5Ah * 59.2V = 207.2Wh, 3.5Ah * 60V = 210Wh). Usein saanut nettisivuja paremman tarjouksen suoraan yhteyttä ottamalla tai ehkä pystyy neuvottelemaan hintaa vielä alaspäin. Kokonaisia akkuja en ole tuolta tilannut (olisin tilannut jos olisin tiennyt firman olemassaolosta custom-akkuja tilaillessa ), mutta muita varaosia (Firewheelin emoja ja akkujen BMS:iä) ja KS16S:n kyllä.
  9. esaj

    Update KS16

    Checked a couple of the update threads, but didn't find much info on what changes with the new versions. I'm still running 1.00 on the S with the old app and completely happy with it (I only use the app to check battery sometimes, and the wheel has worked just fine), but does anyone have a changelog for the newer versions? I'm cautious of the firmware upgrades, since it's not like updating your phone or computer OS, the wheel's not connected to internet, so no need for security updates or such, only if there's either a serious problem with the firmware or it brings something really useful. I doubt there's anything in those updated versions I'd really need, I think someone mentioned the ability to adjust the side lights, but I keep them off anyway... Still interested in what's changed, though. EDIT: Found these from some screenshots: V 1.03: Newly lock successfully alarm (beeping) feature V 1.02: Repair the gyro calibrating datas With the lock unicycle function With the password connecting the unicycle function Calibrate the speed of unicycles I haven't had problems with calibration or speed settings, so I think I'll still leave well enough alone
  10. Pari viikkoa sitten maanantaina (16.4.) näytti tältä: Saman viikon torstaina otin KS16B:n käyttöön työmatkoille, ja käyttänyt sitä joka päivä, vaikka aamulla lämpötila on voinut olla vähän yli nollasta +2:een lähtiessä.. Jäätä ei enää teillä varsinaisesti ollut, paljon hiekkaa kyllä. Viime viikon keskiviikko tai torstai taisi olla eka päivä kun pystyi ajamaan putsattuja teitä pitkin töihin. DSiden kanssa käytiin toissaviikonloppuna heittämässä pitempi lenkki, mutta silloin oli vielä hiekoitussoraa monessa paikassa paksulti. Tänään otin S:n alle ekaa kertaa tämän vuoden puolella ja heitin pitempää lenkkiä, vieläkään ei kaikkia pyöräteitä ole putsattu, mutta paljon parempi jo. Omassa pihassa on vielä varjopaikoissa vähän lunta, mutta näyttää se kevät tulevan, ei enää mene pakkaselle kuin "vain" muutamina öinä viikossa
  11. esaj

    King Song Charger Getting Very Hot

    I have a FLIR thermal camera on my phone, but since it's been winter, no reason to charge up the wheel(s). Have to remember to take pictures of the charger once I do. Maybe just with single charger, I usually charge using two "cheapo plastic bricks" in parallel through a Charge Doctor V2. 200 Fahrenheit (about 93 degrees Celcius) does seem excessive, especially since it's the outer plastic chassis temperature, meaning that likely the internals are running even hotter. Then again, how much quality can you expect for the cheapos? Sounds like they're set up to run pretty close to their limits, hope my house won't burn down...
  12. Onnea vaan uuden pyörän johdosta! V10F on itselle ihan uusi tuttavuus, en ole ehtinyt ja jaksanut foorumeilla enää niin paljon pyöriä... Jos tuo KS16B jää itselle, niin onpahan vara/projektipyörää, en sitä sen kummemmin ole (ainakaan vielä) koittanut mihinkään kaupata. Tuosta runko-projektista löytyy astetta pitempää ketjua täältä, käytännössä se on Firewheelin tekniikka + custom-akut kotitekoisessa rungossa: Läjä kuvia projektin varrelta: https://imgur.com/a/orjAz Videonpätkä koeajosta: Välillä oli jo korkealentoista ajatusta hiilikuitu-kevlar rungosta ja ties mistä, mutta loppujen lopuks piti todeta että jos tehdasvalmisteinen pyörä on (tai ainakin oli, 2015 vuoden pyörillä) vaarallinen, niin tuo on täysi tappovehje Kelien kylmetessä ja työkiireiden keskellä se jäi sitten ensin "tauolle" ja lopulta meni purkuun. Kukin tavallaan Omat matkat on tupanneet olla sellasia 1-2h yhteen putkeen huviajelua yleisillä teillä muun liikenteen seassa, joten vesisade, jäiset tiet ja kuulalaakerien tavoin renkaan alla pyörivä isompi hiekoitussepeli ei oo oikein houkuttanut Pitää hommata sellanen EUC Extremen ajopuku/kaatumahanskat -viritys, niin ei niin haittaa jos vetää naamallaan katua pitkin välillä Tietty jos alta karannut pyörä lentää jonkun autoon tai naapurin 5v tenavan päähän, niin sitten voi tulla jo sanomista...
  13. Muutama sata kilometriä pohjoisempana, vielä on jäätä paikka paikoin ja helvetisti hiekotushiekkaa joka paikassa, mutta viikon-kahden sisään olettasin että kausi käynnistyy. Ylimääräsenä lojumassa muuten KS16B, 680Wh akulla... Custom-akkujakin ois useempia kappaleita (Suomessa kasattu, 4 x 192Wh, kennoina LG:n MH1:t akkula.fi:stä, BMS:t 1RadWerkstattilta Saksasta) lojumassa, hyvin vähällä käytöllä olleet, ei paljon lataussyklejä, mutta aika voi jonkun verran olla maksimikapasiteettia syönyt. Jääneet yli yhdestä projektipyörästä, jos joku noista on kiinnostunut, niin voin katella saisinko kapasiteetit mitattua jne: Helpointa jos nuo saisi Suomeen myytyä, täältä ulkomaille postitus maksaa simona (toiseen suuntaan jostain syystä ei, KS16B taisi tulla 20 eurolla briteistä kotiovelle) ja akkujen kanssa muutenkin hankalaa... Jos ei sitten keksi ite muuta käyttöä KS16S pysyy vielä omana ajopelinä toistaseks, kattoo josko Ninebotin Z-sarjaa tms. joskus hamassa tulevaisuudessa. Mieli ois tehny alkaa väsäämään nastarengasta jossain välissä, mutta työt pitäny sen verta kiireisenä, että jäi ajatuksen tasolle.
  14. Sorry for taking this long to answer, I don't frequent the forums that often these days... the "???" is there, because on the United States-part of the list, I've listed the city & state for the shop, and didn't find the info in the pages. " Locations the shops ship from Although a shop/site/whatever may be listed under country X/city Y (I've usually only extracted the location information from the "contact"-information or "about us"-section in the sites, if such is available and tells their location), it is possible that they only have an office or such in said country/city, and ship through a warehouse or other location in a different city/country. I leave it up to you to find out any issues this might affect (warranty, shipping, import duties, taxes...) before making any orders. If unsure about anything, contact the reseller/manufacturer/local goverment/customs/whatever seems suitable in the case directly and ask them. If you have any suspicions about any entity, the simplest solution is to not order from them. "
  15. esaj

    New Inmotion V10 (V8 Fast)

    Yes, it's relevant, a mosfet that has failed in "open" (non-conducting) position won't cause any rotating resistance on the motor, whereas "closed" (conducting) position will cause the resistance when two phases get short circuited together. The terms "open" and "closed" refer to the circuit loop here, and only closed loops conduct current, probably you termed it the other way around. But even then if only one phase is closed (conducting) and the other ones are open (non-conducting), it wouldn't cause any resistance, it has to be two (or all three) phases shorted together, so that the motor windings create a loop "between themselves". However, this will likely happen as the controller tries to keep driving the motor when a mosfet fails, since one of the phases is continuously shorted to either the negative or positive rail, once the controller switches the conduction of one of the remaining phases to that same rail, the phases get shorted together. There's a bunch of alternative scenarios that could happen there (like a shoot-through when the opposite mosfet in the same half-bridge starts to conduct, strong braking current and/or back-EMF voltage spike when two phases short together in full conduction), but likely when one mosfet fails, the chain reaction following in the next split second destroys more of them, leaving two or more phases shorted to the same or both power rails, at which point you'll notice the motor is braking even when the wheel's otherwise turned off. The problem is that there's nothing except those mosfets that prevent the two phases of the motor from being connected together, and once the mosfets have failed in conducting state, removing power from their gates has no effect (as you've likely noticed, the motors resist turning even if you turn off the wheel or remove the battery, it's the physical connection between the motor phases). If there are two boards and one of them fails shorting the phases, cutting power to that board won't do anything, it would have to be able to cut the short circuit from the motor phases, otherwise the failed board will keep the motor braking while the other one tries to drive it. There would have to be more complicated and elaborate bridge and board design, allowing the failed board to cut the the shorted motor phase loop (actually, disconnect all the motor phases from the failed board) and give the control over to the secondary one. I don't think fuses or relays or such would work, fuses would likely be too slow, by the time it would blow the motor would already be braking hard and you'd loose your balance, and/or using fast fuses, too sensitive, blowing under normal driving circumstances due to a high power spike, like fast acceleration from standstill or accelerating up steep hill. Normal mechanical relays would cause faceplants just on their own, as the contactors would bounce around during normal vibration and knocks on the wheel, cutting the power by themselves. A simplest one I could come up with a moments notice that even has some theoretical chance of working was to use secondary high- and low-side mosfets, that are normally kept conducting, but in case of failure, they would be used to cut the failed mosfets from the loop. "Normal" half-bridge with single high- and low-side mosfets on the left, secondary mosfets in series on the right (the high-side secondary might be P-channel to ease gate drive voltage requirements). Still, this is far more complicated to actually implement in real life than shown here, there needs to be a fool-proof way of detecting the failure of either low- or high-side mosfet, so it won't shutdown just because there's a sudden "normal" current spike there, and it needs to shutdown the failed half-bridge fast. Secondary bridges (or entire secondary board) would then have to take over in a split second to prevent faceplant without any sudden braking/acceleration/coasting of the motor. The secondary mosfets could also fail at the same time if it's a shoot-through or similar, the parts cost goes up since the mosfet count is again doubled (and they're the most expensive part of the board, maybe not singly, but since you'd need 12 instead of 6 or 24 instead of 12 them), the software becomes much more complicated because it needs to monitor and make "smart" decisions what is actually a failure and what is just normal spike, how to turn over the control to the secondary board etc.