Why can you subscribe to yourself?
Topic by NatNoBrains | last reply
I have a portable generator (tiger diesel generator's alternator of 220v 750 watt rated power output) connected to a 1 hp ac induction motor using a pulley-belt system. The rpm of both the alternator of the portable generator and the ac induction motor is 2800 rpm so the size of the pulleys that i used are almost the same. Initially when i bought the generator i tested the output with a digital multi-meter and it checked right.(working powered by the diesel combustion engine). But i have coupled it with the ac induction motor i can only draw out 12 v ac at around 1 amp. I tested this from the same out put plug of the original generator. so I'm wandering what went wrong. Any one have an insight to this I would be grateful for your comments!
Question by nahom.ghawariat | last reply
Hey everyone, I need some help for my project paper. I want to build a self-balancing "one wheel". But I dont know where I can buy a wheel hub motor. I searched on Alibaba and found some fitting ones. A 800W 48V DC Brushless (Wheel Hub-) Motor. But i don´t know which speed motor control is the best for this type of motor. I want to use an arduino uno ! Can someone please Help me finding a motor control ? Thanks a lot :) PS: Sorry for my bad english :) I am german
Topic by Lucafaeth
Ok i know im gonna get alot of crap cause people hate it when i ask them this but the self tying shoelace i dont really feel like spending 20 bucks 4 that and ive been doin magic 4 awhile like 3 years and i just wanna know how to do it if you dont feel like syin it you can emial me at firstname.lastname@example.org thanks
Topic by pyrokid648 | last reply
The Gomboc is a "mono-monostatic" object -- a three-dimensional object that purely by dint of its geometry has only one possible way to balance upright.The challenge intrigued two scientists, Gabor Domokos and Peter Varkonyi, both of the Budapest University of Technology and Economics. They spent a few years doing the math, and it seemed as if a mono-monostatic object could, in fact, exist. They began looking to see if they could find a naturally occurring example; at one point, Domokos was so obsessed that he spent hours testing 2,000 pebbles on a beach to see if they could right themselves. (None could.)After several more years of scratching their heads, they finally hit upon a shape that looked promising. They designed it on a computer, and when it came back from the manufacturer, they nervously tipped it over, wondering if all their work would be for naught. Nope: the Gomboc performed perfectly. "It's a very nice mathematical problem because you can hold the proof in your hands, and it's quite beautiful," Varkonyi says.It's apparently similar to the shape of tortoise and beetle shells, explaining why these creatures can actually flip themselves back over.
Topic by canida | last reply
I'm not sure why I waited so long to post about this but something pretty cool happened to me because of my last contest entry. I entered mySolar Thermally Pumped Hydroponic System in the "keep the bottle" contest. For some reason I didn't win ;-), however, shortly after the contest I received a PM. The PM was from the Harvard Graduate School of Design, they were putting on a conference on Ecological Urbanism and they wanted my project to go on display for six weeks. I, of course, was honored and after negotiating an enormous fee (j/k) I shipped the project up to them.Recently while looking for some more info on the subject I stumbled across their Flickr Pool and two photos of my project. I have to say, it's almost fantastic that a project, composed primarily of empty soda bottles could go from my backyard to the halls of Harvard.And, obviously, this would never have happened if Instructables didn't exist, so my heartfelt appreciation to Eric and the fine people behind the scenes of the website. So without further ado, the pictures.
Topic by Tool Using Animal | last reply
I have an idea to make a bunch of smallish balloons that have a LED sinside and small circuits that would control small heating elements to randomly change the density of the air inside the balloons, making them rise or fall. Just as a fun art project, making a bunch of them and letting them into a room for a party or something. A couple of issues I have: I'm having a hard time figuring out how to calculate the buoyancy, though that may have to come later once I decide on all the components. I don't want to use any lighter-than-air materials like Helium, just regular air heated up. I've been trying to find some small ceramic heaters, but I haven't had much luck. Ideally, something like this seems like it would work perfectly, but I need to find some that I can buy in quantities less than 20,000: http://cdsk.manufacturer.globalsources.com/si/6008801115398/pdtl/Heating-element/1070197186/Surface-Heating-Elements.htm Whatever I choose would also need to heat up and cool down pretty quickly so the rising/falling would have a stronger effect. I might be asking too much here. I'd need the whole circuit to be pretty small and lightweight. If I use an Arduino Uno, could I just transplant the ATmega328 into the balloon? If I used a small watch battery, would that even provide enough juice to operate an LED and a heating element? Anything bigger seems like it would be too heavy. As for the casing, I plan on whipping something up in Blender and printing it out in lightweight plastic. It would have to hold the circuitry and be airtight to keep the balloon sealed. Any thoughts or ideas would be greatly appreciated!
Topic by jemtan990 | last reply
I dont live in the nicest town and i thought about getting a self defense weapon but tasers are illegal where i live, I have a kuboton but it does not make me feel safe so i was wondering if anyone knew how to make a proficient self defense weapon on the cheap.
Question by CR15P33 | last reply
Question by whiteynut | last reply
I need this info for a tech class one day project we're build and raceing cars out of a set amount of materials and it needs to be self proppelling also anything on making it aerodynamic would be appreciated.
Question by cryptex | last reply
Arduino fires up okay, but I can't get the relay to energize, so the pump does nothing, of course. Great project, but some of the steps aren't clear enough for this retiree. For instance, in Step 23, "Plug the black wire from the circuit board to the ground socket on the Arduino." Which "black wire?" There is no complete schematic, so I'm guessing at what I'm trying to find. Also, the Arduino sketch in Step 19 (Randy Sarafan) didn't compile or load into the Arduino until I inserted the missing semicolon after the line "int dryValue = 700" Could sure use some help, as Mama is looking forward to having her vegetable plants watered when we're not home! Thanks in advance! --Fred Lochner, Boulder, CO
Question by fredlochner | last reply
Permanent drip living without suckers (electricity)
Question by tekaka | last reply
A news report on CNN describes a teen-ager who, in her high-school science class, diagnosed her own Crohn's disease by catching a granuloma on a microscope slide she was studying.As a "teachable moment" for good science education, it's great, but I'm not sure having to diagnose one's own disease is really what "do it yourself medicine" is meant to be about!
Topic by kelseymh | last reply
Hi folks ,as said above , would like to install a row of red high-power leds into the rear of my bike seat post to give a hidden , high-tech look :-). Elements of design to be considered ; to run off 2-4 AA batteries , to use 5-7 5mm leds , to use " off the shelf parts " , no hand built electronics , to have constant and flash modes , would consider adapting an existing product ( e.g. cateye light unit ) For the installation i intend to drill a row of 5.5mm holes , 25mm apart , with the led heads sealed in place just protruding the surface of the metal post. The led leads would be drawn up and out of the top of the seat post into the saddle area and is where the battery pack would be strapped in. Any electronics could be housed inside seat post or under saddle. A handle bar switch would be nice but not essential. I feel confident about the wiring and fitting of the components ( electrician by trade ) just need a pointer with the electronics. Cheers Pete.
Question by biff55 | last reply
The cup doesn't really stir itself on its own, but it has a ball that fits into a groove that can be swirled around to mix up your tea and sugar. It's a funny concept that's looking for a manufacturer, but is there a problem with stirring out there that I'm not aware of? Also, do you want to be swishing HOT tea in your hand in the morning before you've really woken up? Sounds like a noisy recipe for disaster to me and that's assuming you can keep the ball and cup together after a couple of washings. Linkvia Neatorama
Topic by fungus amungus | last reply
Does anyone have a printable checklist, maybe even a speradsheet that is/can be use to calculate and track home energy use? I want to do a self energy audit and be able to track energy use over time. I've looked on google and can't find anything like that, most are just guides for what to look for, nothing to actually use to document info with.
Question by RedneckEngineer | last reply
VLSI testing is process that is used to determine that chip is good or faulty VLSI chip is tested by test equipment and some self test circuit just for example we made microcontroller then we can test by automatic test equipment , we use test vector to determine fault 1.test vector < microcontroller chip > output response 2.test vector output response 3.test vector output response Q I did not understand that self test circuit and fault model built within vlsi chip or we connect external fault model circuit to test VLSI chip ?
Question by vead | last reply
Hey guys, I am doing GCSE Electronics and I've decided that I would like to create a fully automated robot which will roam around on a patch of grass while avoiding any objects in its path (I would assume by using infra-red). I have searched the internet briefly but have not found anything useful. I would very much appreciate it if anyone could point me in the correct direction. Thank you very much, Lawrence
Topic by Fysh
I'm hoping someone can help. I have a handicap that makes opening drawers and cupboards impossible via touch. Aside from foot. I've been trying to come up with a solution for this for a while now. I need something that takes up little, if any drawer space. Is relatively cheap (since it needs to be replicated across multiple locations). Can be opened/stopped/closed via a single foot pedal. And that will stop if it encounters some sort of obstruction. Actuators that are able to open drawers to the size needed are very expensive, and I'm unsure if they have the stop function in case of blockage. Anyone have any suggestions/
Topic by sanguish | last reply
Hi all, I am always amazed at the ingenuity here and after many years of being fascinated I would like to ask my first question. I'm thinking of getting or converting/building an electric cycle. I've been told by local dealers that none except the very expensive have a recharge facility for sat when you go downhill or are freewheeling, That seems a waste to me so I am thinking ... why not buy a used wheel with a hub motor and fit it at the front wheel and that raises the following questions in my mind ... Can hub motors be used in reverse as generators? Would the output be speed (rpm) dependent and if so then if said cycle has say a 36 volt system would it only charge the battery if the 'generator' is producing 36v or close to? If so would it be better to find perhaps a 24v hub motor to use as a generator and charge the battery via a variable input, 36v output step-up? I appreciate it will be less than 100% efficient when both using electric at the motor and charging at the 'generator' but would anyone have any idea how inefficient? I'm fit enough to cycle on the flat but would appreciate help on the hills!! I assume I will need a diode or similar ... does anyone know where I can find a suitable circuit diagram Lots of questions I know ... sorry. David
Question by HRobinson | last reply
I'm looking for a cheap version of the self winding watch winders like they have at http://www.ewatchbox.com/stsiwawi.html. I haven't found anything under $70! I searched this site and couldn't find anything either.So here's a challenge for you gadget gurus out there that think this might be something fun to make!I look forward to seeing what will pop up here!JM
Topic by JibsMan | last reply
As I searched for something on health, and didn't find one. Of course, the normal caveats are true, since none of us are able to diagnose or treat disease, this is only to point one in a possibly correct direction.
Topic by Goodhart | last reply
Can you make a one speaker mp3 amp that amplifies the left channel, and drives a single speaker, and uses the right channel as the amps power source? The right channel could be rectified and smoothed, but would it be enough power to run an amplifier that amplifies the left channel and drives a small speaker. Would it work? Would it be louder than simply running left and right speakers directly off the MP3 player?
Question by zylascope | last reply
Being adept in this kind of thing certainly gives one an edge in innovation by a wider range of what is physically possible to create. I am currently a high school student with no intention of earning a formal degree in mechanical engineering in the future, however, I do take a keen interest in it and would love to become knowledgeable enough to successfully, safely, integrate it into my inventions. I'm wondering how many of you actually have a background in this field and if not, how did you manage to teach yourself?
Question by orangejuicedisco | last reply
In this city it is a political chore to get speed bumps put in, particularly in the alleys. For the most part, bicyclists just bu-bump over them; but, when u are a transportation cyclist like me (often heavily loaded) and u must negotiate these suckers daily or hourly, u begin 2 think that a few more inches between their two halves could make a big difference in time, money and wear. Note: some of them have been installed in an arcane manner to, for example, accomodate intersecting rainwater channels (which are cut into the pavement). All of the above problems could often be circumvented by simply widening the space between the two halves of these devices by a few inches---like three. Slightly wider space between the two halves, called the "crotch" by some, would make it easy to ride down the alley and avoid both pinch flats and bu-bumping, bu-bumping, bu-bumping. P.S. An full swing from a sharp axe won't work....
Question by Rapel Teetaw | last reply
I'm starting to plan a self-balancing unicycle and I notice several people that have built them are using 450-500W motors. I'd like to use something a bit more robust, like 750W @ 24v, due to terrain. I'm wondering if that's too much and if the guys that are using 500W are happy with the results? Has anybody tracked their current (amps) usage? My guess is that unless you're going full speed and uphill you'll rarely hit full wattage on your motor except for temporary instances. One of the challenges I'm finding is that there are motor drivers up to 25A at 24v or 36v that can handle a bit of surge, but then it takes a huge leap to 160A and 400A surge. I don't think I need something that large and expensive, but my electric motor experience is limited. Could some of you more experienced guys chime in with a bit of advice? Thanks, Gyv
Topic by Gyvven
I am planning on constructing a completely self sufficient home, with the energy created in DC using a water wheel, windmill, and/or generator. I wanted to stay away from inverters (unless REALLY needed), and wonder if i can make dc plug sockets and plug the AC appliances into the DC (building rules and regs wouldnt apply) . They would mainly be simple kitchen appliances eg mixers, and a lot of tools. They would be run from a bank of 12v batteries. i would also use DC lights in the house.i thought this may be possible from this instructables- https://www.instructables.com/id/Run-AC-Tools-on-Batteries-Directly,-without-an-Inv/any help would be GREATLY appreciated!?
Question by joel.riley1 | last reply
Hi Forum. My wife and I have just purchased a piece of land. It was a stretch but the plan is to check out of the rat race once and for all. What we are looking for is ideas, plans, resources, links etc for a DIY home that won't require a mortgage from hell. Any and all ideas greatly appreciated. Also interested in looking at prefab as an option. Thanks. Thoughtfission.
Topic by muddywaters | last reply
Curious observation from my mother's recent 3 months in the USA, she says she is unable to bake well when she was in the USA. Now, given mum is a pretty amazing baker on this side of the pond, I am wondering why that might happen ? I wondered if its "American flour", as opposed to "UK flour" - the recipe, would be the same kind of things, memorised over the years, like a simple scone, fairycakes, pastry. Her main complaint was that items didn't brown, even at the same oven temperatures as she uses here, and after repeated experiments with the same recipes.
Topic by steveastrouk | last reply
I know it would not be 100% efficient, or even close for that matter. But I was wondering how much battery life could be "recycled" by directly projecting the light from the flashlight onto the solar panel(s)? Say at a 45 degree angle beneath the light. Obviously this wouldn't be a high output LED, and another question at that.. Would a Red LED be more efficient or would the PV cell not do so well with Red LED? Thought this would be a neat idea even if it would only recycle 5-10% battery life. I would love for someone to implement this idea into a project and see how efficient it is.
Question by xSoFx | last reply
I just wondered, If you could take an electric motor like the ones that they use in the electric cars and motor bikes and by adding a generator/alternator ,or turbine to recharge your batteries as it is running. Like making an electric continual self charging battery powered motor.
Question by regdab | last reply