Efficiency contest

Disclaimer: I may be biased, since I have an entry in the running.I am very confused as to why the current leaders of the efficiency contest are in the contest at all, nevermind winning.One is not instructions for making anything. It just says "watch less TV". It may be good advice, but it is not a DIY project.One is a recipe for bread. It may be wonderful and delicious bread, but it has nothing to do with being green.One is about making a suit out of a sleeping bag. I suppose this would allow you to turn down the heat, but that is a bit of a stretch, (besides, so would a sweater - and the instructable doesn't say anything about this being the reasoning).I don't mean to disrespect these fine instructables, I am just saying they are totally irrelevant to this specific contest.But not only are they in the contest, they have been in 1st, 2nd and 3rd place since voting opened 2 days ago. Who is voting for these entries, and why?

Topic by JacobAziza   |  last reply



Efficient LED lighting? Answered

I want to power 3x 0.5W LEDs in series with 3x AA Ni-Mh batteries (input voltage will range from 2.5 to- 3.7 ). The total forward voltage is around 10volts, and the current of the LEDs is 150mA. I've tried using a Joule thief but it's quite inefficient, even with different transistor / toroid / resistor configurations (even with fast switching Darlington transistors) the maximum current I've been able to get at the LEDs is less than 100mA, and many energy gets lost in the process, it seems the resistor between the coil and the base of the transistor slows down the switching process and limits the current. I need a more efficient way to power the LED's, either an improved design or a LED driver chip. But trying to keep the efficiency rate around 60-70% or more. I have found a design that claims to be more efficient (see picture), but I'm not sure about if it will deliver 150mA.

Question by Victor805   |  last reply


Potato cannon efficiency? Answered

I created a potato cannon that only has straight pieces of PVC.I have seen other designs where the combustion chamber is wrapped around 180 degrees with two elbow pieces thus making the cannon more compact.  Does anyone know which design is more efficient as in terms of launch power and speed?

Question by bobert610   |  last reply


Household Appliance Efficiency (Slowing the meter)

Hello, Does anyone have an idea how I can build a device or circuit board that I can hook up a computer  to monitor the efficiency of Appliance and hopefully write a computer programe to maximize the efficiency of the appliance and minimize the power drawn from the power grid. Basically slowing down the meter while the appliances still operate at their full potential? Thanks 

Topic by derf1973   |  last reply


If LED lights bulbs are so efficient, then why do they have cooling fins? Answered

Most of the LED bulbs now sold as incandescent replacements have cooling heat sinks on them. If they have such great efficiency, I would expect minimal waste heat with no heat sink needed. Do they get too hot to touch as well?

Question by LongToe   |  last reply


if we design solar water heater by two paralel cover glasses. what is the function of the outermost glasses? ?

What is the best range between two glass covers (in mm)? how to calculate the efficiency of this SWH? this swh is length, width, height 137 cm, 126 cm, and 10 cm. thanks for the answers

Question by diaz.zahara   |  last reply


Will removing a rear seat move the centre of gravity in a minivan too far forward? Answered

A family member frequently drives around in the van all by themselves, which I'm sure is an enormous waste of gasoline. Removing one or both of the rear seats will help reduce the weight of the vehicle and improve the efficiency a tiny bit. That said, I was wondering if doing that would cause handling issues due to the centre of gravity being farther forward. Also, winter is long and icy here, so rear traction is an issue 5 months of the year.

Question by zalf   |  last reply


How to get 9 volt from a computer power supply? Answered

To save some energy i thought it would make sense to remove all those small powersupplys. They all transform pricey power (24 eurocents per kw/h here) into heat. However, in my computer is a powersupply that actually is very efficient, also, if i take more energy from it, it wouldn't have much more loss. Right now my computer uses about 54 watts if idle (i selected the components to be as efficient as possible). My DSL-Router uses 14 watts, but i guess most of it goes away as heat in it's own little PSU. The DSL-Router needs 12 volt and my computers PSU can deliver that, and since the DSL-Router is only needed when the computer is switched on i plan to use the computers PSU to power it. I have a pair of speakers with an internal PSU and AMP. After opening them i saw that both are on separated boards. The PSU gives 9 volt to the AMP and gets quite hot while doing it. The problem: as far as i know there is no 9 volt power connection in the computers PSU :(.

Question by tecneeq   |  last reply


How do I figure out the cost differential between turning on an inefficient furnace and using oil-filled space heaters? Answered

The big deal is that this furnace also heats the upstairs unit of a duplex, which i also own and rent out to my brother in law.  the deal is that he spends maybe 5 nights per week at his girlfriend's house.  so, if i turn on the furnace, all of the heat that goes upstairs will be wasted.  i'm interested in learning how to measure energy usage and learning how to determine the usage difference between running the furnace, which is about 50 years old and runs at about 50% efficiency and three pretty standard 7-fin oil-filled space heaters.  the flat in which i live is about 800 sq.ft. and the upstairs space is about 600 sq.ft.  the windows are old, but are covered with plastic shrink film for better insulation.

Question by hobbssamuelj   |  last reply


Study: Ethanol Worse for Climate Than Gasoline

Ethanol is under fire again: At first blush, biofuels such as corn ethanol and soybean diesel seem like they would be great from the standpoint of global warming. The crops soak up carbon dioxide from the atmosphere as they grow, and that balances out the carbon dioxide they produce when they're burned. But until now, nobody has fully analyzed all the ripple effects of this industry. And Tim Searchinger, a visiting scholar at Princeton University, says those effects turn out to be huge. "The simplest explanation is that when we divert our corn or soybeans to fuel, if people around the world are going to continue to eat the same amount that they're already eating, you have to replace that food somewhere else," Searchinger says.Searchinger and his colleagues looked globally to figure out where the new cropland is coming from, as American farmers produce fuel crops where they used to grow food. The answer is that biofuel production here is driving agriculture to expand in other parts of the world."That's done in a significant part by burning down forests, plowing up grasslands. That releases a great deal of carbon dioxide," Searchinger says.In fact, Searchinger's group's study, published online by Science magazine, shows those actions end up releasing huge amounts of carbon dioxide. The study finds that over a 30-year span, biofuels end up contributing twice as much carbon dioxide to the air as that amount of gasoline would, when you add in the global effects. The rest of the article (and radio broadcast) is here

Topic by Goodhart   |  last reply


Most efficient CO2 sensor?

I found this CO2 sensor. http://www.robotshop.com/parallax-co2-gas-sensor-module-2.html Any one know of a better one?

Topic by hthnc-student   |  last reply


A More efficient joule thief Answered

I need to make a joule thief type of thing that can up the power from a 0.55V source to a simple LED. I know that the joule thief is not the most efficient circuit which is why I am asking if you know of an efficient circuit I can use.

Question by physics_dude   |  last reply


Efficiency of DIY bitcoin miners?

First, I would like to say that I do not know if this is the place for this question, but: I have just heard of bitcoin mining and started to look into it.  I have learned that pretty much the only way it is plausible is through the use of a machine dedicated to mining the bitcoins, not through using gpu's anymore apparently.  But I have seen that these machines are expensive, so naturally I would want to build a DIY one if I started this.  But are these dedicated miners even efficient? And what if they don't have the top of the line components?  I tried to look this up myself but I don't really understand the hash rates of these machines so I don't know what is considered an efficient rate.  And, in my current situation, I don't pay for electricity or internet so now would be an optimal time to do so and maximize profitability.  So, do these dedicated miners work efficiently enough to make it worth while to build/buy one? Especially if I don't pay for electricity or internet?

Question by texpert   |  last reply


Solar Thermal Design and efficiency?

I have finished building and testing my diy solar thermal collector. i decided to paint the outside framework black, will this make a difference? also i was wondering how to work out the efficiency and power it can produce? the temperature difference was 17 deg going in and 29 going out at a flow rate of .36 litres a minute and the solar radiation was 800 watts per m^2. the temp difference might seem low and there a 2 reasons for this. 1)im in ireland and 2)i never bled the radiator so i have a feeling the water only flew across the bottom rather than circulate. Thanks

Question by rich5007   |  last reply


Energy Efficient Dog Door

Winter is coming and I have four dogs and two cats. We installed a dog door to the outside some time ago, but it's a big air leak. Even though we replace the door every six months, it's only plastic with magnets on the edges, and doesn't always fall back into place. I've tried various solutions, but what I really need is a solid door that locks into place, or a door that opens and closes with a trigger. Automatic dog doors cost about $350.00 - $450.00, and require the dog wears a special collar. I'm not looking for security, I'm looking for energy efficiency. Can someone please help? I know there are lots of others in the same position.

Topic by mattyw21   |  last reply


High efficiency coilgun design

Hello there I need some (a lot of) help with my project. I've started to design a high efficiency multistage coilgun. The main feature of the design is using the self-inductance formed in coils that were shut down for accelerating the following coils. To perform this, we can divide each coil into 3 segments (lets call them subcoils), connected with a wire and power all them 3 with a single capacitor. At first, the current from the capacitor is flowing through all 3 segments and a projectile is being pushed through the first segment. Than the first sensor is being activated with the projectile and it switches the power flow to only second and third subcolis As the current in the first subcoil is changed, the self-inductance directed in the opposite direction is appearing. In theory, we can use this power to increase the current in the following segments. The same thing is happening between second and third segments. And I want to place 3 of this stages (9 subcoils in total) I will use 8mm caliber projectiles, 40mm or 50mm length. I chose 5200mkF 450V or 6800mkF 400V capacitors, 2 of them in parallel for every stage (6 capacitors in total) Yes, I know it sounds way too powerful, but that's my actual goal. It's not my own idea. I have learned it from here http://gauss2k.narod.ru/adf/gs3seg.htm (русские вперёд). So, some problems had appeared. I can't figure out how to properly calculate the required inductance of the coils. In the source it is said that the inductance of the first subcoil should be equal to two of the second and the third subcoils (L1=2*L2=2*L3) to achieve the best performance. Also, my rough estimates show that peak current through the coil will be about 1,5-2,0kA for 3,0-4,5ms. This is quite a lot! I'll have to manage this energy and choose the power switches rightly. To sum up, I will be glad to hear your opinions about this idea. It's kind of controversial, but I hope it's not a certain failure.

Topic by CosmoKnight   |  last reply


Green car mod roundup

Treehugger has a nice roundup of mods that people have made to their cars to make them more efficient or run on alternative fuels. They even included the Honda Accord that runs on trash in the list, which is pretty cool. Other mods include wood-burning cars, biodiesels, wood-burners, solar-power, hydrogen, and aerodynamic enhancements. Check out the link for the slideshow. Note: there are 17 slides, not 17 cars. 17 DIY Cars Hacked for Fuel Efficiency

Topic by fungus amungus   |  last reply


selective room heating?

I just turned on the heat before going into my room to go to bed. My roommate and I are in about one fourth of the whole house (and will be for about six hours), yet every room is being heated. This seems like a huge efficiency problem. Are there commercial systems out there that can heat selective rooms? If not, are there ways of making such a system? Can I just tape cardboard over the vents?

Topic by moisture   |  last reply


Audio: 8 hours of Amory Lovins lectures

Video with slides http://www.rmi.org/sitepages/pid231.phpmp3 audio only http://sic.conversationsnetwork.org/series/si-energy.htmlAmory Lovins runs the Rocky Mountain Institute, working on cars made from thermoplastic/carbon re-formable body panels among other projects.He's a charismatic motivational speaker on the subject of energy solutions. Listen to this stuff to get enthused again after you get burned out by hearing about what our idiocracy is doing to us and the world. It's a really it's nice to hear him saying that thetechnology solutions exist and all our dreams will come true once we switch tothem. And this crisis is just the thing to get us off the dumb old methods thatare only used from habit.

Topic by TimAnderson   |  last reply


HHO generator improves fuel efficiency of petrol engine!

Reproduced verbatim from The Fortean Times issue 249, republishing from FT35JUNE 1979On the 15th a demonstration of a "revolutionary" energy device took place at an undisclosed location in the UK. Iowerth Thomas, 58 a Welsh inventor, hoped to interest both government energy officials and an Arab consortium. Mr Thomas had been experimenting since 1936 with ways to make petrol engines burn more efficiently. His "bolt-on" device promised between 25 and 40 per cent efficiency using "the electrolysis of tap water", plus a cleaner exhaust. The government scientists' response - that it was impossible - spurred Mr Thomas to demonstrate it for them. He reported to the motoring correspondent of the Daily Telegraph that his stationary engine ran for 112 seconds with his device and for 77 seconds on the same amount of petrol without it. The usual objection to electrolytic systems is that the energy needed to run them is greater than that produced. With some sarcasm, New Scientist sniffed that the device needed to be much smaller than the room-size contraption Jones used. What really stoked their scorn was Thomas's reply when asked how it worked: "It's beyond me," he said. That was the last we heard of him and his promising device.How has this technology improved in the last 30 years?L

Topic by lemonie   |  last reply


Sandia, Stirling Energy Systems set new world record for solar-to-grid conversion efficiency

31.25 percent efficiency rate topples 1984 recordALBUQUERQUE, N.M. --On a perfect New Mexico winter day -- with the sky almost 10 percent brighter than usual -- Sandia National Laboratories and Stirling Energy Systems (SES) set a new solar-to-grid system conversion efficiency record by achieving a 31.25 percent net efficiency rate. The old 1984 record of 29.4 percent was toppled Jan. 31 on SES's "Serial #3" solar dish Stirling system at Sandia's National Solar Thermal Test Facility.The conversion efficiency is calculated by measuring the net energy delivered to the grid and dividing it by the solar energy hitting the dish mirrors. Auxiliary loads, such as water pumps, computers and tracking motors, are accounted for in the net power measurement."Gaining two whole points of conversion efficiency in this type of system is phenomenal," says Bruce Osborn, SES president and CEO. "This is a significant advancement that takes our dish engine systems well beyond the capacities of any other solar dish collectors and one step closer to commercializing an affordable system."Serial #3 was erected in May 2005 as part of a prototype six-dish model power plant at the Solar Thermal Test Facility that produces up to 150 kilowatts (kW) of grid-ready electrical power during the day. Each dish unit consists of 82 mirrors formed in a dish shape to focus the light to an intense beam.The solar dish generates electricity by focusing the sun's rays onto a receiver, which transmits the heat energy to a Stirling engine. The engine is a sealed system filled with hydrogen. As the gas heats and cools, its pressure rises and falls. The change in pressure drives the pistons inside the engine, producing mechanical power, which in turn drives a generator and makes electricity.More here:http://www.sandia.gov/news/resources/releases/2008/solargrid.html

Topic by ewilhelm   |  last reply


do resistors use up power? Answered

i.e. is a circuit with resistors much less efficient than having the correct voltage/current from the course? i'm thinking here mainly about dimmer switches and also parallel LEDs where each would need its own resistor. Cheers.?

Question by jamesjamesjames   |  last reply


What is the difference between an in line 6 car engine and a v6 car engine in terms of performance? Answered

I currently own a 1989 Mercedes 260 e series and it has a in line 6 engine under the hood. I was wondering what the difference between an in line 6 and a v6 are in terms of performance like efficiency and horsepower.

Question by bobert610   |  last reply


Jevons Paradox

I recently read a thought-provoking article in the New Yorker: "The Efficiency Dilemma" by David Owen. The main gist of the article is that as our machines use less energy, we use them more, thus negating any environmental benefit we hope to achieve. This is known as "Jevons Paradox". You can read the abstract and article here, but you have to be a subscriber for the full article. You can read a commentary, with excerpts, here. Please discuss...

Topic by aeray   |  last reply


Optimisation of pneumatics

Another interesting thing I found through research, a flaw in most over-under designs and pressurizing the stock, I have found that for every 90 degree elbow between the chamber and the barrel the resistance to the air is the same as adding 20 feet of straight pipe, this can be changes by using two 45 degree fittings put together to make a gentler turn or by using curved fittings instead of elbows, the gentler the turn the better. From this I have found that the simple straight cannon with the chamber directly behind the barrel as is shown in the picture below (please note this cannon is one I found from Google just to emphasize the point, and this is in pneumatics only). also to increase efficiency look at my other topic:https://www.instructables.com/community/best_chamber_to_barrel_ratio/(once again if you have found my research incorrect please tell me, I wont get fired up =)

Topic by cheeseboy   |  last reply


Why is not all the energy transfered from the firing pin to the bullet in a K'nex gun? Answered

When the firing pin hits the bullet in a K'nex gun, why is there some energy lost? If all the energy from the firing pin was to transfer to the bullet, then the pin would stop before it hit the back of the gun. Is there some way to use all of the firing pin's energy to completely transfer to the bullet?

Question by ~KnexBuild~   |  last reply


Efficient/High output Joule Thief?

Right now, I am looking for schematics for the most efficient (1 cell and 1 LED) joule thief, to use as a durable reading light. I right now favour Quantstuff's 2 transistor SJT (http://quantsuff.com/LED2.htm) but I am not sure whether it is the most efficient. I've seen several others, but since they all claim to be equally as efficient, i'll have to rely on the experience of other tinkerers and hobbyists. So: what's the most efficient or high current or high voltage joule thief you know of?                                                                                                                          Thanks.

Question by .Unknown.   |  last reply


Efficient House in Maine has no Furnace

This house in Maine has no furnace and will generate more power than it uses. With some extreme air-tightness and solar panels this is one super efficient house. It even has mood ring-style lights on the side to let you know how it's doing. Green is for Net-Zero use, yellow is on the border, and red for pulling more from the grid. Linkvia MAKE

Topic by fungus amungus   |  last reply


¿What power source is more efficient?

For a project I have to decide between a mechanical generator (I.E. one attached to a bike's wheel) o an array of cheap solar panels.Anyone has experience with this? What is your advice?I only need to supply power to recharge four generic AA batteries once a day.Thanks!

Question by Daniel FranciscoD1   |  last reply


A more efficient way to stamp paint

Hi all! I have been working on a crowd source campaign for elaborately designed dice for a while now and have a problem with my home manufacturing process...hopefully, someone can give me some ideas. I need to find a quick and efficient way to apply paint to the raised surfaces of the dice faces. You can see in the rendered pic the 3d printed file that I'll be making the mold from. I made the numbers extend out instead of going in to simplify the painting but need to get down a system of applying the paint. I was thinking some sort of stamping but thought that was only good with ink. Any input is appreciated...

Topic by dmenegon   |  last reply


CHALLENGE 60% efficient solar build

I would really love to see this Instructable be done but i don't have the technical background or resources to do so. It seems like a pretty easy build and looks like it can be done with common items. If the project is done correctly it should be a very powerful source of energy for free. It converts solar energy at 60% efficiency which is almost twice as much as current solar panels. It works by converting solar heat into electricity by heating hydride (which is hard to find but i think it can be replaced with a refridgerant) into a gas, which generates pressure to run a motor which runs a generator producing electricity and then the gas is converted back into the liquid state. The project will replicate Solar Powered Electric Generator Please contribute the time to building this it will pay off tons. Thanks To Everyone Who Helps.Mark

Topic by BTBAMYEAH   |  last reply


Higher efficiency (high amp) 12V regulator alternative to 7812

I need a high efficiency 12V DC regulator to supply my thermoelectric modules (they're very inexpensive so I had no choice but to use them). I found that the modules are most efficient at 12V @ ~7A each. I could use many 7812s in parallel but they are too inefficient and too much energy is lost to heat. Is there any alternative? Electricity bills are going up so it'd be very good if I can find an extremely efficient step-down or step-up regulator, short of using an expensive 'gold standard' ATX PSU (which are usually upwards of 500W so the power savings don't matter).

Topic by arikyeo   |  last reply


Boost curcuit amperage issue? Answered

I am planning to make a small boost converter similar to mintyboost. I am using a boost IC that will give me about 92% efficiency with the voltage i have. The output is 5v at 500ma, and the input voltage is 2.4v. Would the ic suck up more than 500ma per hour from the batterys?

Question by astroboy907   |  last reply


The Newman Motor Challenge !

I was recently approached by someone claiming the old Newman Motor wouldn't be good for anything.Well, I was a little bit offended by this as I already had my little toy version of it as kid.At that time though it really was just a toy for me.Critics still say the Newman Motor is nothing more than some interesting machine.And even the biggest followers will admit it is not a free energy machine, just a very efficient one.I experimented with, what some call fringe science, now for about 30 years.And it all started with math and my interest in unusual ways of dealing with problems.So what's behind the challenge?The original design was suprisingly simple as you can see in the above Wiki link.Just a spinning magnet in a (split) coil.What you don't find anywhere though is real details on the how to.Sure, you need to have some sort of contact linked to the rotation and timing is critical but what does it all do?You can build a drt simple model in a few hours with stuff you might have around already.Quite a few Youtubers are happy to share their creations.The actual challenge is to come up with what Newman really did inside his drum.And also why I think it is not the full potential his machine had.Build a simple Newman motor and check for how long you can let it run on a charge super capacitor.Then sit back and read some of the other magnet stuff I wrote.After that come up with a better design ;)I started to create some 3D models that need testing once I find more free time - should take some leave one day..But for those with little patience and an interest in the Newman Motor I decided to share my current idea:For some it might be really confusing although they know motors and magnetic fields.Those just playing with magnets might have it easier for once as they can pretend they followed my thoughts ;)The original design used two coils and a rotating magnet.If you consider how the magnet creates an electromagntic field in the coils then you have to wonder right away how it can spin.And most designs will indeed need a push start to get going!You can't have electricity produced without the magnet spinning and you can't make it spin without electricity!The current from the battery or capacitor can only flow at the short moment of contact on the axle.This moment needs to be timed "mechanical" as we don't want to waste any power on not required electronics.If you ever bothered to check the timing of a Newman Motor then you realised the collapsing electromagnetic field at the moment of contact actually is in reverse to what the manget has in that position.Unlike any normal motor it means the magnet produces most of the power the coil needs to make the rotor spin!So far for the well known facts, now for my fiction:I would like to call my version the Aussie Newman Motor as all things downunder are just different ;)Here are my current desing mods, that I freely share so everyone can benefit form many years of experimenting to save a lot of time.1. Instead of two coils a not-really-bifilar coil is centered on the axle.The coil is created like two stacked relay coild that have no bobbin and a "dint" to allow the axle to pass through.Without the big gap of the original less of the magnetic field strenght is lost and the coil is far closer to a homogenous magnet.2. The timing done by salvaging a simple DC motor's contacts and brushes.This allows for far higher currents and if the salvaged motor had enough poles also for a very short "burst".3. The axle contact is made with a cleaned steel bearing.After cleaning very conductive copper based lubricant is used in tiny amounts to prevent corrosion and provide a lower resistance.The clear benefit is that with the new timing system a lot more current can flow.Initial tests with a mock up model showed an increase in run time from the capacitor of about 15% already.With proper bearings and a salvaged DC motor I hope to reach 18 to 20% more than the original design.Now why the DC motor if a reed contact or hall effect sensor would be even faster and with less resistence?Neither can handle really high currents without additional electronics ;)Plus of course I wanted to leave the door open for the Aussie Newman Motor 2020.You might now say "Why bother if the above improvements are already so great?".If you followed my elsewhere for a while then you know the Newman Motor is only 2D but I prefer 3D or more harmony if you like.Right now the imagination of people re-inventing Newman's machine is limited.They try to get on the horse from behind - literally.Fancy electronics, machined parts and so on.But they never go 3D ;)You got it? :)There is only two coils!!The magnet rotates, same as the contact on the axle.One set of coils for each contact the salvaged DC motor has.Each set aligend to the corresponding contact.And now you will ask "How do you plan to connect that to a single DC power source?Well, that is why it will be the 2020 model - my time for tinkering is sadly limited because I still need to work to support myself.But if you consider that the original as a good model can run for over 10 minutes on a supercapcitor then ask yourself how long it could run on 4 or even 8 coil sets.And although there is no such thing as "free energy": There will be still space for more coils.Or other coils to just provide electricity that does not power the motor.Critics will now see their chance and state that if we add a load to these additional coils then this will cause a strain on the system.Of course they are correct here.If, however, the load is mechanical then the motor needs to supply basically the same additional energy.Plus all mechanical losses.The question is: How much mechanical load can we add before the motor is down to the same efficiency of a very efficient DC motor? ;)And what if our Aussie Newman 2020 would actually violate the laws of physics?We can calculate how much electrical energy would be required so a given motor produces a fixed amount of torque.Or we can just measure it, the beauty of science...We can do the same in reverse of course.Let's say a mechanical pump would require 500RPM and 100Nm of torque to pump 100 liters per minute.Then we could calculate what sized motor we need to drive the thing and how much power the motor would need.So again: What if the Aussie Newman 2020 would require far less than what science makes us think and still does this job on a simple 12V lead acid batty of 4Ah?Just saying... ;)I hope to have a presentable and working 2 coil system by May, so stay tuned!In case you are faster or even beter then of course feel free to show off your results or to post a link to your Instructable so everyone can verify it.

Topic by Downunder35m   |  last reply


Would a high wheel bike generate be more efficient than a typical stationary bike generator?

High wheel bikes have a bigger wheel that would turn the generator more often per pedal.   right? Would there be a greater mechanical advantage? or would it just increase the work load like going into a higher gear?

Question by Houdinipeter   |  last reply


LDR and/or PWM for energy efficient 'smart' dimmer?

Is there any way to combine a Light Dependent Resistor or other light sensor with a Pulse width modulator to (energy efficiently) dim indoor lighting in the presence of sufficient natural light?  Thanks!

Question by bbawco2   |  last reply


What is the most efficient way to transfer motion? Answered

What is the most efficient way to transfer lateral movement to vertical movement via a ramp. The following curve is equal on both sides of the apex, if that is the correct term.  Is this the best way to transfer the movement to strait vertical or should something else such as a long start to the incline and then a sudden shoot up.

Question by jj.inc   |  last reply


World's most efficient solar dish? - MIT

A team led by Massachusetts Institute of Technology students last week successfully tested a prototype of what it says may be the "most cost-efficient solar-power system in the world," revolutionizing global energy production.The 12-foot-wide dish, made of a lightweight frame of thin aluminum tubing and mirror strips, concentrates sunlight by a factor of 1,000, according to the Cambridge, Mass., university. It can create heat intense enough to melt a bar of steel. More from ZDNet

Topic by Goodhart   |  last reply


dc-dc Buck vs boost efficiency

Hi guys. When you  use solar panels and have gadgets with different voltage requirements  that you want to power up. I need atleast  2 different outputs, 5v and 12v  ,   so which is most efficient ,  12/15v panels that you  regulate to 5v , or  5v panels boosted  to 12v? is there any general advantage in either case and i,m talking about using  cheap ebay switch regulators / boost converters,  not anything expensive hi tech. regards

Topic by kristerh   |  last reply


More efficient bike charger for USB devices?

I' been inspired by these bike lights from reelight.com. I have a set of these for my bicycle for reliable and very effective lighting. It's stated they are powered by "pure induction". There's got to be a way to harness the energy from both wheels to charge a USB device (5 volt) in the same manner. Instead of using a friction generation mechanism bike charger or bike generator.Any thoughts?

Question by rhow   |  last reply


efficiency while charging through solar cell.

we know that solar panel gives maximum power at particular voltage.which is a bit less then the actual rating of the panel. my aim is to get a constant voltage across the battery,okh. but can i do sth by which i can get such const voltage 4 which the power provided by by solar cell is maximum. i can introduce a microcontroller which will continuously check the voltage ......and itwill get stuck at dt particular voltage...but i am getting puzzled with dat,ne idea plz

Question by sumgupta89   |  last reply


efficiency (not efficacy) of CPUs/computers? is all the power input technically converted into heat? Answered

It has recently been fairly hot where I live, especially in my room, where computer hardware seems to be increasing the temperature by a good 5-10*F over other rooms. This got me thinking, and was wondering if any computer engineers/physicists may know the answer to this one. If I am running a power-hungry intel CPU, coupled with RAM and maybe SSD storage (I wish!) is all the power fed into my system being converted into heat? In other words, if my rig consumes a good 250W-400W, and there are no transducer devices drawing power (LEDs or lights, speakers/microphones, monitors, motors, heaters, phone chargers, etc,) and all the energy is used for data collecting, and calculating, then is *ALL* the energy converted to 250W-400W of thermal energy (heat)? or do the data operations themselves in fact require energy and maybe entropy or something plays a role? where it would seem that 400W of input yields an apparent 399.981W of energy output + data.

Question by -max-   |  last reply


Very old shielding materials and techniques for permanent magnets and resulting possibilities

Forromagnetic meterials are not just called that for no reason.It comes from ferrous - iron.Iron has the highest permeability at normal temperatures.That means a magnet is attracted to it very strongly.We utilise this for transformer cores, the stuff inside a relay and the moving latch of the relay itself.Like current from an electrical system magnetic fields like to take the easiest route possible.Air is a very bad medium, so any iron close by will be prefered even if it is at a slight distance.You can check with a magnet, a steel bar and some iron shavings - please cover the are with plate first ;)Slightly less known is the option to also guide and extend the magnetic field this way.If you check how far the magnetic field of a magnet reaches and note that distance,then you can add some steel bars or rods at the poles - the field will extend through the metal.The most powerful example of this are the shielded magnets used for hooks or speakers.Except for a tiny area the entire magnetic flux goes through the metal.So in this lefover area the magnetic flux density will my many times greater than what the magnet alone would be able to.What most people don't know is that magnets also interact with other magnets in terms of their fields changing and distorting.The Halbach Array is a good example of this.Seen as a single magnet the array would have one weak and one strong side instead of even strenght for both.Wherever magnetic fields change a conductor can produce electricity or current.This in return causes an electromagnetic field that opposes the one from the magnets.Just drop a magnet through a copper or aluminium pipe ;)Since these distortions are widely unknow to the hobby tinkerer mistakes can happen ;)In the early days of exploring science some people already knew about shielding.And they also knew that certain metals have certain properties.Where it is quite hard to create a good coil from steel wire, copper works fine as it is not magnetic.What would then a copper shielding do?If you have two moving magnets with only a tiny gap then the resulting field distortions are quite huge.A copper shield around the magnet like a pipe would then react to these changes and also create a megnetic field that works in relation to the enclosed magnet.In simple terms it means the shield would let the magnet appear weaker or stronger depending on the field change.A quite old document I found gave some hints on how people thought in different directions back then.It was in regards to the design of a magnet motor by the way.Here various magnets were shielded in tube made of a copper-bismuth-alumium alloy.These tubes were then electrically connected so it created a single loop conductor.The claim was that the resulting electromagnetic field of this ring would drive the fields of the enclosed magnets sideways out of alignment.Like bending straight pastic tubes sideways.This "pulsating" would always happen when the magnetic binding forces reach max and so basically drastically weaken this binding effect.Another document talks about a "magnetised brass rod".A holes of the rod diameter is drilled through a block magnet.Not from north to south but through the middle where the flux is greatest.The claim here was that if that rod rotates fast enough a very low voltage with a very high current will be generated.Sounds easy and interesting enough that I might have to test one myself one day.The best one however is what I consider a hoax or being as good as Starlite.Someone back in 1908 claimed to have created a material the reflects magnetic fields.In lame man's terms it would be like an insulator around some electrical wire.The claim and some pics showed it, was that no magnetic field can pass the material.Or to be correct only a tiny fraction of what would be possible through air.A small magnet inside a longer tube of this material would create almost the same attraction to steel at the tubes ends as on the magnet itself.Measurements showed the field strength would be almost equal to a long mangnet of the same field strength.Imagine guiding the field of a big and powerful magnet through a tube around some corners or other magnets and then end in just a tiny hole for the entire flux...Too bad he never shared his secret formula to anyone knows to mankind.Isolation...Imagine you have an array of changing magnetic fields and quite strong magnets.Then you might face the problem that your focus on the "working" end neglected the other end of the magnet (stack).Providing some iron core material will keep thes field lines contained and away from interfering with your setup ;)But it also allows to use te otherwise unused end of your magnets more directly.For example by guiding to another magnet to affect its field strenght ;)Placing a sheet or steel between two magnets in a setup provides a "shared pole" so to say.If you have a north and south pole on a rotor at a distance of 5mm then a sheet of steel between will drastically weaken the strenght and reach of this combined field.It is like pulling the arch between the magnets down to make it more flat.And at and an angle the resulting field will also be slightly angled ;)Capping...When I first encounter this many years ago I couldn't really make sense of it.Quite complex..If you check the magnetic field lines with iron filings or similar then you notice how they go in a rounded manner from pole to pole.This is because the single field lines are of equal polarity and will dirve apart like opposing magnets.By capping the ends of a magnet you provide a short.Instead of diverting out like mad they will follow the cap and create very intersting magnetic field in return.If both poles are capped it is like pressing the magnet flat but without having a field on top of the oles - only aorund the center part.For this the thickness much must match what is required for the flux density.As a rule of thumb: if the end is still very magnetic then it is not enough material tickness ;)Interacting fields in a tube...This one is quite old too and seemed to have found no usable inventions apart from simple magnetic spring replacement systems.But it gave me some clues about Tesla "earthquake machine" ;)If you place a magnet in a tube and at it's ends magnets with opposing fields to the one inside then you can fix this magnet in place.Push one magnet deeper and the distance from the inner magnet to the other end will shrink the same amount.In this old paper two coils were around the pipe with the inner magnet between them.In this gap and at about the same width as the magnets length another coil was placed.Violent shaking would then create electrical energy at much higher level then modern shaker torches.In return an AC current on the outer coils would cause the inner magnet to move back and forth to create electricity in the center coil.According to the paper possible uses include: core less transformer, measuring minute changes in AC voltages, providing free power from a running motor...The last one had me stumbled for a very long time.Until I considered a different configuration.The whole thing is basically a linear DC motor - with correct timing of course.And in some motors we use permanent magnets.I am starting to wonder what would happen if we would design a rotor magnet like this?The running motor would be subject to constant field changes that affect the rotor.And a normal motor is always "even".By using four magnets instead of one we can push the field really flat.This means the area where the coil would operate (about 1/5 of the magnets area) will have a much stronger field.The resulting torque should be higher by about 25% !!Even a simple two coil model setup should show a significant increase in performance here.Timing is critical here but I tried some calculations based on 8 poles and the required "on times" for the coils.In a standard motor configuration with a single rotor magnet the coil is active for about 12° of the rotation.With a 4 magnet configuration this "on time" can be reduced to under 8° of the rotation to get the same amount of torque.An energy reduction of about 4% if you neglect losses and only think in time.If you think in terms like impulse energy then we are talking of about 15% !Shorter on time but still much higher flux density overall than for the long standard timings.Going the long run now:If you check how most DC motors work then you realise soon that for most one rule seems to followed.Only use one coild pair at a time.This is quite contradictive if you consider the geometry and options.A dual commutator would allow to use a second coil pair with a field OPPOSING the magnets instead of being attracted to it.After all: on you bike you pedal with both legs and not just one...And if you do it professionally then yu do the same as I suggested for the motor - you use the up pull of your legs as well.Doing it brushless only requires amodified h-bridge desing to drive the second coil pair at the right timing.Some will now say that it requires twice the energy, I say that for the same motor size your get twice the torque!Just imagine what that means in possible weight reduction for a motor - or its size to deliver the same torque at the same power levels when a normal motor is used ;)The more poles the more complicate the precise timing but no big deal really with modern electronics.Can it be improved even further?I though long and hard about that one until I considered EMF.A DC motor produces a lot of it when the elecromagnetic field collapses in the the coils.We do not utilise this energy...There is a tiny delay until the released energy levels are at max.My theory is that it should be possible to divert this energy into another coil set.If that coil is not the next active but still within a strong enough field area then the EMF would actually add to the drive of the motor.Only downside is that according to my calculations at least 16 poles would be required to get an optimum result.Way above of what I can create in my little garage :(In theory it should then be possible to reach about 98% efficiency for the motor....

Topic by Downunder35m   |  last reply



Voltage Stabilizer Efficiency Loss (Extra power consumption)

Hello All, I am using an 1KVA Voltage stabilizer for my Fridge. The power quality is really poor here in India, and these things are mandatory. I learnt the lesson hard way :-(.... Well that aside, i would like to know what would be the power loss or Extra consumption these devices use when regulating power. Actually,i could use a general lecture on how Stabilizers work!

Topic by bhvm   |  last reply



what are some math problems to make a efficient circuit? Answered

I am trying to make my own wind mill using a stepper motor, capacitor,led, and a resister. My problem is that my dad wants me to make it more efficient meaning making the led go brighter and longer. I curently have 11 capacitors in parallel ,one resister. what are some math equations i can use to find out how to make this more efficient and how do i use the problems? 

Question by lookwhatjoeysmaking   |  last reply


Simple, efficient, low-cost, solar energy equipment

I am looking for a DIY simple, low-cost solar water heater and solar light that will work in any kind of weather and still be able to supply atleast some working heat and light. Please suggest.

Topic by rseni   |  last reply


What would be the Easiest and most efficient way to make this?

I need a circuit that has a switch between 3 and 5 minute off times and a 3-5 second on time that repeats.  It needs ot ahve an on off switch and be as as efficient and compact as possibly, and fairly easy to make. Thanks in advance for any help! I need to order parts for it, so the parts I need would be nice.

Question by aarroozz   |  last reply