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They are starting to use X-ray machines to check for motors at some UCI events. e: http://www.cyclingnews.com/news/uci-uses-x-ray-machine-to-search-for-mechanical-doping-at-the-tour-de-france/ for example
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Feb 7, 2017 23:46
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JawnV6 posted:I'm curious if there's any cycling enthusiasts here. A video showed up on my FB purporting to show "mechanical doping," or "cheating with a motor." Right now the governing body is mostly either using thermal cameras or waving an ipad around the downtube area to detect changes in the magnetic field caused by having a big ol' chunk of metal where it doesn't belong..
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Feb 7, 2017 23:59
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Why are cyclists so hell bent on cheating anyway.
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Feb 8, 2017 00:14
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Splode posted:Nah this forum is full of experts in every field. Yeah I don't doubt this, I more doubt the wisdom of constructing a giant metal box on wheels full of explosive batteries running at killin' voltages that can go 60+mph based off of forum posts. Like would something like that even be able to pass an inspection and be roadworthy without every piece of it being some UL listed pre-made thing or having an engineer sign off on it?
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Feb 8, 2017 00:16
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"Mechanical doping" is an impossibly dumb term. Just call it cheating, there's no dope involved at all Anyway IIRC the most common motor cheating strategy right now is to stack a battery and motor into the seat tube, with the motor at the bottom driving the crank through a modified bottom bracket. I'd imagine that it's pretty easy to detect that with magnets or a sensitive magnetic field detector. Or maybe even just by tapping the tube, since the hollow ultralight carbon fiber is going to sound totally different from one with a bunch of mechanical parts crammed inside. Sagebrush fucked around with this message at 01:33 on Feb 8, 2017 |
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Feb 8, 2017 01:25
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The motors are real tiny though since even 10-50w advantage over a long enough time is crazy good
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Feb 8, 2017 02:25
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I’m surprised that adding batteries isn’t counterproductive on longer courses. Batteries don’t contain a particularly large amount of energy per unit mass.
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Feb 8, 2017 02:32
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flywheels. No battery, no magnetics. The whining noise and potential for catastrophic deconstruction would be bonus.
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Feb 8, 2017 02:49
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Murgos posted:flywheels. No battery, no magnetics. The whining noise and potential for catastrophic deconstruction would be bonus. I can't imagine the massive quantity of angular momentum would be very easy to hide
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Feb 8, 2017 02:54
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Cumslut1895 posted:I can't imagine the massive quantity of angular momentum would be very easy to hide I was going to post a video of the ol’ “gryo in a briefcase” prank, but now I can’t find it.
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Feb 8, 2017 03:09
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Zero VGS posted:Believe it or not I've done both electric bike and electric car conversions before... There are no simple options here but the voltages in question arn't super exotic. Particularly stepping down from 312 to 24V should be easy. Many standard AC to 24V supplies will run off DC though it will be harder to find one that says so in its spec. But the reality is that 220AC becomes ~300V DC when rectified which is the standard first stage in a modern switching supply. The only downside to putting DC into this is that current might not share between rectifier diodes as intended and/or it might throw off control circuitry. The final solution here may still have batteries on the output because nothing beats their ability to handle large transient loads. Stepping from 24V to 300V is also feasible with a boost converter, though more difficult than the above, but the main thing is what's controlling your charging? A lot more goes into charging lithium than supplying the raw voltage, as I'm sure you know. asdf32 fucked around with this message at 03:55 on Feb 8, 2017 |
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Feb 8, 2017 03:49
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Platystemon posted:I’m surprised that adding batteries isn’t counterproductive on longer courses. Batteries don’t contain a particularly large amount of energy per unit mass. Yeah this is my first thought as well though I also recall that bikes may have a minimum weight? If so batteries would be great ballast to hit the minimum. Also perhaps it's worthwhile to have an extra boost stored up even if it costs joules overall.
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Feb 8, 2017 03:55
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Sorry to prolong the derail but I went down a wikipedia rabbit hole and wound up on the more generic page on "technology doping" which has this gem:quote:Ionized shirts Wow how can they let them get away with such bold-faced use of ions like that 
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Feb 8, 2017 04:55
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Zero VGS posted:Believe it or not I've done both electric bike and electric car conversions before... a) Don't do this one, it's a serious engineering challenge, and there are basically no off the shelf parts that even begin to do the hard parts for you. A good power engineer could make it work, given a pile of money, event then it'd still be basically the wrong way. b) Could be done with off the shelf components. As other people have mentioned that ~300vdc down to 24vdc isn't a huge problem. Charging the batteries would be done with a standard high voltage charger. The kicker is that most of these systems require high voltage in, but there are plenty of off the shelf inverters out there that would handle the voltages and power fine. Somewhat expensive, but the most reliable and the easiest to get to work. c) What I'd do if I was trying to save every dollar possible. It could be made much cheaper than b, and you could even make basically all of it yourself. It's also fantastically more work to do, and much more likely to have reliability problems, design faults, etc.
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Feb 8, 2017 06:27
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Yeah once I heard you were using tesla battery packs and EV chargers, and that you had converted vehicles before, it all seemed way more doable. The hard parts of charging an array of lithium batteries are going to be already done by the tesla battery cell circuitry, so your solar cells just have to produce the same sort of output as the standard electric vehicle charger (though presumably with way lower current). Good luck, keep the thread updated with your adventures!
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Feb 8, 2017 08:02
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Sagebrush posted:I'd imagine that it's pretty easy to detect that with magnets or a sensitive magnetic field detector. When I said they wave an iPad around the bike I wasn't being facetious. Here's their magnetic field detector in use: 
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Feb 8, 2017 08:17
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MisterOblivious posted:When I said they wave an iPad around the bike I wasn't being facetious. Here's their magnetic field detector in use: They even have a special app just for this, that I'm sure some company sold them for $100,000 despite all it doing is using the onboard magnetometer and spitting out data.
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Feb 8, 2017 08:45
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Zero VGS posted:The more solar panels in series, the more susceptible to any kind of shading affecting the output of the entire pack. To reach a voltage that high I'd need the entire array in series. It is also much more efficient overall to use an MPPT charge controller as it can optimize the performance of the solar array, which a normal EV charge controller won't do at all. How about running the pack at full voltage, solars at a lower voltage, then using a lower voltage MPPT battery charger into either an extremely large capacitor or a standard lead acid pack as a buffer. Then you can step up the low voltage buffer pack to whatever voltage you need to charge the main battery pack. It might be less efficient due to the double charge cycle, but it sounds simpler.
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Feb 8, 2017 18:41
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longview posted:How about running the pack at full voltage, solars at a lower voltage, then using a lower voltage MPPT battery charger into either an extremely large capacitor or a standard lead acid pack as a buffer. Extremely large capacitor you say?  http://www.ebay.com/itm/144x-Maxwell-Capacitor-Bank-2-7V-BCAP3000-Boostcap-UltraCapacitor-/162185792665 To be honest I was sort of considering it... only $4000 for ~500 watthours of juice to instantly vaporize me! Cumslut1895 posted:I can't imagine the massive quantity of angular momentum would be very easy to hide You would be unable to steer the bike with a flywheel as you would not be able to lean into turns. Someone got it working on a motorcycle prototype, but the finished product is vaporware: http://litmotors.com/c1/ On the plus side, I could add a railgun to my van.
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Feb 8, 2017 19:56
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I love that we now have capacitor banks that can be measured in loving watt-hours Anyway what's the thread's latest recommendation for [free] PCB layout tool? I heard a bunch of bad things happened to Eagle or something, and I haven't had to design a board for a few months so I'm not really sure what's going on or what to use anymore
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Feb 8, 2017 19:59
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ate all the Oreos posted:I love that we now have capacitor banks that can be measured in loving watt-hours KiCad
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Feb 8, 2017 20:01
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Platystemon posted:KiCad Oh hey that looks a lot better now, I remember checking it out years ago and it looked like complete garbage then but now it looks pretty deece, thanks! e: About Page posted:Digi-Key Electronics Aww that's nice of you digi-key 
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Feb 8, 2017 20:57
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I use altium at work and haven't heard anything nice about both eagle or kicad in comparison.
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Feb 8, 2017 21:09
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Splode posted:I use altium at work and haven't heard anything nice about both eagle or kicad in comparison. That is because Altium costs thousands more dollars than free.
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Feb 8, 2017 21:13
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What are you guys opinions on roll your own DIY DC-DC boost converters? edit: removed gibber Jamsta fucked around with this message at 00:10 on Feb 9, 2017 |
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Feb 8, 2017 21:39
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There's lots of info out there, that'll be a good project.KnifeWrench posted:That is because Altium costs thousands more dollars than free. Yeah I know, I'm not looking forward to having to learn one of the others. Altium is still not an easy to use program, to hear people say nice things about it is terrifying.
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Feb 8, 2017 21:44
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ate all the Oreos posted:They even have a special app just for this, that I'm sure some company sold them for $100,000 despite all it doing is using the onboard magnetometer and spitting out data. Indeed. They paid a company that manufactures adapters that lets doctors attatch endoscopes to iPhones to develop it: http://endoscope-i.com/
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Feb 8, 2017 22:21
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Jamsta posted:What are you guys opinions on roll your own DIY DC-DC boost converters? Boost is one of the three main basic topologies (including buck and buck-boost) so there are tons of resources and ICs that can do as much or as little as you want. Note that all the major players have tools that will give you entire boms for standard types of DC-DCs so you barely have to do any design if you don't want to. Whether a beginner should tackle it depends more on voltages and power than anything else. If you want to learn something try linear, simulate in LTSpice, and choose a more generic PWM controller.
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Feb 9, 2017 01:50
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Jamsta posted:What are you guys opinions on roll your own DIY DC-DC boost converters? Go for it. It’s a basic circuit that you’ll use, or at least see, all the time. Find a controller/converter IC (converters have the switching transistor integrated—works well for lower‐power applications, but tend to come in tiny packages that are a pain to hand‐solder) that looks good, read the datasheet, and follow its recommendations for component selection and layout. Don’t try to make it work on a breadboard. It might work fine, but SMPS are the kind of thing where you can run into mysterious issues due to parasitic resistance/capacitance/inductance. Before you edited the post, you were contemplating making a bench supply, right? That’s more challenging due to the power and noise requirements implied, as well as the demand that it operate over a win erange of voltages and currents
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Feb 9, 2017 02:07
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Splode posted:There's lots of info out there, that'll be a good project. Use CircuitMaker if you're yearning for free Altium. I use it at home and it is an easy transition from Altium at work.
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Feb 9, 2017 03:05
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ante posted:Use CircuitMaker if you're yearning for free Altium. I use it at home and it is an easy transition from Altium at work. Cheers, I'll look into it
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Feb 9, 2017 04:12
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ate all the Oreos posted:I love that we now have capacitor banks that can be measured in loving watt-hours I actually like KiCad, which is to say I preferred it to eagle, (though I've never used altium), but it definitely has it's rough spots, and the way it separates part from footprint makes some people feel weird. When the new head developer started up he pushed for a new stable release, and it instantly got tons better. (well, more that basically all the previous improvements actually were in the easy to download version, rather than making you compile it yourself) Also, diptrace is pretty great. Their pin limit used to be more onerous than the eagle size limit, but now that you need to pay $65/mo for 4 layers in eagle, being limited to 300 pins isn't near as bad. Power and ground planes are just so nice, and make easy rf stuff actually possible. (or use your old version of eagle for a lot longer  )ate all the Oreos posted:Oh hey that looks a lot better now, I remember checking it out years ago and it looked like complete garbage then but now it looks pretty deece, thanks! That's the second thing I've heard recently about digikey that makes the management sound like genuinely good people.
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Feb 9, 2017 05:32
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Do any of you know if there is any such thing as a ready made remote potentiometer. I know there are motorized ones with a remote control, but are there any where the remote is another potentiometer, or otherwise a rotating or sliding adjuster rather than buttons? Like I turn a knob or a slider on a remote and the potentiometer turns elsewhere.
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Feb 9, 2017 07:21
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asdf32 posted:If you want to learn something try linear, simulate in LTSpice, and choose a more generic PWM controller. Good point, I have a tendency to go in head first, so a sim would be a good start. Thanks Platystemon posted:Go for it. It’s a basic circuit that you’ll use, or at least see, all the time. Noted. A work collegue who does analog elec said the same thing today. Said I might be able to use trackless perfboard if I bunch up certain components but will need to be very aware of the issue. quote:Before you edited the post, you were contemplating making a bench supply, right? That’s more challenging due to the power and noise requirements implied, as well as the demand that it operate over a win erange of voltages and currents At the moment it'll just be a test project for learning. If I can get the analog side working ok I'll step up to writing my own switcher IC code so I can control V, I and P in software. I did originally want to do a higher current DC conversion but as you say, probably better to start small and work up. Can anyone recommend a good place for buying ferrite cores. Aliexpress/Ebay sell cheap but they often just say the size and not the core grade. Is that going to be a problem?
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Feb 9, 2017 12:37
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His Divine Shadow posted:Do any of you know if there is any such thing as a ready made remote potentiometer. I know there are motorized ones with a remote control, but are there any where the remote is another potentiometer, or otherwise a rotating or sliding adjuster rather than buttons? Like I turn a knob or a slider on a remote and the potentiometer turns elsewhere. There are a fair number of options for motorized mechanical potentiometers, though they're pricy from what I recall, and there are also digital potentiometers which can be controlled via digital logic from afar. What's the application, resistance range/precision, and wattage needed?
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Feb 9, 2017 14:36
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I was just wondering if it might be feasible to make my homemade TIG pedal into a wireless with some simple off the shelf components, it uses a 10k potentiometer, don't know about precision, I just bought a cheap one and it works well enough, think it's a little more than one turn for it's range.
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Feb 9, 2017 14:50
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I have a 555 oscillator that I would like to "turn off" by using an LM339's open collector output to shunt the 555's output to ground, is this bad? Can the 555 source enough current to burn up the LM339? I tried it on the breadboard and neither got particularly burning-hot but the 555 did warm up a tiny bit which I've never seen a 555 do before. The 555 is driving a MOSFET and I want to make sure it can turn the MOSFET on quickly and hard so I'm a little hesitant to put a resistor in series with it, though I guess a 250-500 ohm one just to limit current would probably be fine...
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Feb 9, 2017 16:38
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ate all the Oreos posted:I have a 555 oscillator that I would like to "turn off" by using an LM339's open collector output to shunt the 555's output to ground, is this bad? Can the 555 source enough current to burn up the LM339? I tried it on the breadboard and neither got particularly burning-hot but the 555 did warm up a tiny bit which I've never seen a 555 do before. The 555 output is strong. With all its other pins (like reset..) it seems there should be a better trick for turning it off than yanking the output. Or add a buffer of one kind or another to the output (like an open drain mosfet) that can be turned on/off. Jamsta posted:Good point, I have a tendency to go in head first, so a sim would be a good start. Thanks Winding your own core is cool. If you don't want to digikey will have a good selection of inductors that should work for boost converters in typical ranges of frequency/voltage/current. I also highly recommend coilcraft which has the best website of inductor manufacturers and also has their own store and free samples.
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Feb 9, 2017 16:52
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His Divine Shadow posted:Do any of you know if there is any such thing as a ready made remote potentiometer. I know there are motorized ones with a remote control, but are there any where the remote is another potentiometer, or otherwise a rotating or sliding adjuster rather than buttons? Like I turn a knob or a slider on a remote and the potentiometer turns elsewhere. Possible cheap way to do it (warning I haven't had much coffee yet): Hook an RC servo up to the shaft of the slave pot, and use a pot to control the pulse width of the signal driving the servo. You could make the pulses with two multivibrators (555s), the first one triggers the second on a regular timebase (I think RC servos want 20ms). The second is monostable and configured so you can adjust the ON-time with your control pot. The width of the ON-time of the PWM signal sets the position of the servo, which will turn the slave pot to the commanded position.
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Feb 9, 2017 17:06
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asdf32 posted:The 555 output is strong. With all its other pins (like reset..) it seems there should be a better trick for turning it off than yanking the output. Or add a buffer of one kind or another to the output (like an open drain mosfet) that can be turned on/off. I simulated pulling the Reset pin down in LTSpice and it didn't turn the oscillator off, it just made it so that the second it went high it went low again (so like a 1% duty cycle). Admittedly this is probably just LTSpice's weird modeling of the 555 and not how an actual 555 would behave, I'll try a real one later I guess.
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Feb 9, 2017 17:07
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