Are there any alternatives to piezoelectric transducers?

I saw a post about an energy-generating device on shoes which generates electricity when walking. Piezoelectric transducers were used to generate energy but not enough to charge the battery full or even half full. Are there alternatives to Piezoelectric transducers that generates more energy than piezo? Thanks.

Question by charlotteferriols   |  last reply


Building a strong electromagnet, need advice Answered

Hi trying to understand how to build an electromagnet It must be 38-40 kg strong, and powered by 1,5-3v rechargeable batteries (operating for at least few years) and using as few amp as possible, it will be switched on and off 1-2 times per sec I know that it's possible cause it exists already; http://www.grainger.com/product/2KFP1?gclid=CjwKEAiAxNilBRD88r2azcqB2zsSJABy2B96VIJ19MORYbL2E3XKvdOrg6bK6_U-Ko7P7ZAGq3_UqRoC5Kvw_wcB&cm;_mmc=PPC:GOOGLEPLAA-_-Security-_-Locking%20Systems-_-2KFP1&ef;_id=VLan-gAAACg-Rw6I:20150114173308:s Mine just needs to be a little stronger and work 24/7 I would be thankful if you could propose any other source of constant energy (to replace the batteries) or a solution to make them last longer

Question by Maxc13   |  last reply


Solar "Generator"

Since I've always wanted to do something like this and I found this site, it's about to happen! I found a smaller version with what I wanted to do at Popular Science but I want to do something on a larger scale. I do have some questions though that I'm hoping someone can answer or point me in the correct direction.I'm going to describe what I'm doing with what and what I have questions with.I'm going to be buying this solar panel and charge controller kit. Sunforce Solar Panel With Charge ControllerA deep cycle 115 AMP Hour 12 V marine battery from Wal-Mart with Plastic Battery caseSalvaged wood Toy BoxMeter Question: How to meter how many amp hours I have left or how charged the battery is? What kind of meter to buy? Where? (not too expensive <20 bucks or so) how to hook it up.A 12 V accessory outlet with on off switch Question: I'm putting an inline fuse before the switch, 15A the line fuse goes on the + (positive) side correct?A 700 Watt 6.25 AMP DC to AC converter with 4 outlets connected to it. Question: can I put a breaker or fuse between the 4 outlets I'm going to be plugging into on the outside and the plug being plugged into the DC to AC converter? If so how?USB ports for charging with on off switch. Question: how do I convert the 12V to 5V in an easy way? I've seen some creative ideas on here for charging VIA salvaged USB ports but I don't want to have to hook it up to my power inverter if I don't have to. Cooling/ventilation for the entire thing. Any ideas how I might cool/vent it? Currently I'm thinking of using old computer fans and put them on both sides of the toy box and have 2 blowing and 2 blowing out. Having the fans run off of the solar panel during the day and either have a switch to change it to battery at night (if it's too warm in the house) or maybe photo sense it? Temp sensor to turn it on and off? Or a switch to turn it off completely. I'm just looking for idea's to keep the battery (and to expand to be more than one battery) cool/ventilated. If you have examples or detailed description on how to do it that'd be great. I'm not one to steal ideas so I'll credit the idea's I'm given if I use them =)I'm going to see how much I can run off of this and how long. Hopefully save some big time energy also!Thanks all!

Topic by oddie1212   |  last reply


Are carbon neutral fuels good for the environment? Answered

I'm sort of confused about carbon neutrality and it's impact on our environment. I feel like I'm over thinking it, but could someone explain to me what exactly makes a carbon neutral fuel clean? If it's clean burning at all? I'm interested in making biofuels specifically algae fuel, and this is a term that keeps popping up.

Question by thecoonskin   |  last reply



The future of "mobile" energy...

Right now our current standard is still to use LI-Ion batteries when it comes to rechargable and power demanding devices.We all want more power for our phones, laptops or battery powered tools on the job.And we also want to be able to charge our batteries faster and faster.Back in the old days a D-Cell like lead acid battery in a flashlight was good for about 3 hours until it started to dim a bit.With up to 4 batteries inside they were not just heavy but also quite hazardous.Chargin was usually done over night and you just hoped they were not blowing up while charging.I spare you the other types that came after and that we still use as they all have their good and their bad sides.If we trust our marketing experts than quite soon we will only have electric cars on our roads and battery the size of a suitcase shall be able to run your car for hundreds of miles.The ideas of graphite based batteries or those using crystals and their forming reactions are all great and promising.Some will certainly make it to the consumer in a few years.The one thing that we are never told though is where all the energy to charge those batteries is supposed to come from.Replacing the combustion engine with electric motors is one thing but if no fossil fuel is used....Energy does not come out of thin air!Right now a lot of countries already struggle to provide a reliable power supply grid and distribution network.If you ever enjoyed a scorching hot day during a blackout caused by everyone using too much electricity you know what I mean...The population is growing as fast as the energy demand for our industries.Solar and wind are well and good but without proper storage solutions of not real use because no one can really predict how much they can produce.You know, weather and such things...If we trust our so called experts than all will come together really nice.By the time we have really powerful batteries we will have enough alternative energy supply chains up and running to keep them charged.I have a few issues with this entire concept, so let's see what other people have to about this:Imagine you have a nice and big cabin somewhere really remote and beautiful - but with no electricity for miles.Obvious solution for the modern hunter or nature lover is to invest into free energy.Free because that is how your solar, battery and inverter system would be advertised.You buy the stuff and after that all the electricity comes for free - the things pays for itself!Reality is a bit off though as you need to maintain and replace the costly batteries over time and such things.All this however totally changes for a residential home.Getting a huge solar system on your roof is no problem.Getting off the grid next to impossible.You see, once (or even before) you sign up for an electricity contract it is defined that your home is in a residential area.This brings certain limitations like the requirement to connect ot gas (if available), water, sewage and electricity.Only way to enjoy your "free" energy is by getting a good deal with your supplier.Some countries do it differently but around here it goes like this:Whatever you use still comes right off the grid.That is because your solar system really struggles to cope with load changes and providing surplus back to the grid.And since your meter is not capable ofworking properly with it either...To make it "fair" it is metered how much you use and how much you supply.Most companies here even do this on at least an hourly base - just to fair...For your bill the amounts are then adjusted.What you supplied is taken off.Sadly in most cases going negativ is not an option - if you provide more than what you use only your supplier is laughing.To make things worse what you supply is valued far lower than what you get from the grid.Often the difference is above 20%.Control....Around here quite a few people basically covered house, shed, carport and all with solar panels.This was while we had a great subsidy from the government to go solar...After now over three years most of these people still struggle to get anywhere near even for their investment.Without the grants the timeframe to break even was estimated to be around 12 years - which is about the time for when you need to replace the lot anyway and start over.Some do get nice savings on their bills though but families with kids not so much...If you have little to no chance to get your investment back before you have to replace it, then it is not really that much of a good deal after all.Imagine in town with hundreds of small houses everyone would be able to get the same money back for the electricity they provide...Pay 18 cents per kWh from the grid and get 18 cents perkWh for what you supply and once you provide more than you use you get money back.The providers won't allow this to happen as it means they not just loose some money but also they would lose control.How could they justify another price hike?How could they explain the blackouts?Why should tey pay you at all... ;)If a city with enough open and unused space would decide to go solar on a huge scale and while add also add a lot wind turbines....Someone would need the electricity provided and someone need to step in for those times where demand is above supply.Here the old triangle of power goes into full swing....You see a city or town would need also need a sub station to handle the electricity and to distribute it to the town houses, shops and so on.Funny thing is that only a "provider" can do such things.Doing it privat is usually only possible in really remote areas, like big mining outposts that just have no other option than using generators or solar/wind.And in most areas a town or city is no longer allowed to be a provider of electricty - at least not in the drirect form.Buying in bulk is no problem, having your own supply system however is not in the books.Right now most, if not all the big wind and solar farms are owned and operated by energy providers.There is billionaires everyhwere who could build a solar and wind farm the size of Texas if they really wanted but they won't do it either...Starts with the land, goes over the usage rights and won't end with activists claiming how bad it all is.Means it won't happen and if it does then the energy providers get together and claim they guy might have money but does not have the right to provide energy unless he actuall starts a corresponding company and plays by their unwritten rules.Can we still dream about it though?The dream is kept alive like the fire of hope that is only a tiny amber.If you sign up for electricity you are asked if you would like to pay bit extra so your electricity comes from alternative sources.Why is that bad, after all it is green?The initial investment might be huge for a wind farm but after that it is more or less just providing mone out of thin air.You can look the cost up for the new windfarm build near you.Same for the electricity prices in that area.And also the expected output of the entire farm.Do the math and calculate how quickly they break even....Once they do it only profit but you still pay the extra to go green.A bit like the new road that came with a toll....After 5 years the motorists paid it off but 10 years later they are still being charged while the road is disintegrating...Now add electric cars and our constantly rising consumption to the mix...We can't provide the electricity ourselfs as we don't get fully paid for it, we can go off grid either.The atom as the source of electricity is being phased out slowly as well.Finally as some might say, considering the thausands of years we have to deal with the produced waste and what aftereffects the storage might bring.Our providers will keep their grip on us for as long as they can.No government will stop them as in return they wouldn't have electricity.A cold war if you like.We never cared how much fuel our cars use until the OPEC decide to limit supplies and drive the prices up.And you can see the riches especially in Saudi Arabia.For most of the big OPEC players it really does not matter anymore whether or not they have oil or not.They make the same or even more money by other means and more modern means now.After this initial shellshock we woke up and decided that for the shopping trip of the wife a small car with just 4 cylinders will do.Overcrowded cities and roads also pushed us more into thinking small.Again it took force to go further, this time by governments slowy "going green".Emmissions, greenhouse gasses, polution, particles and corbon monoxide...Sounded all godd in the ads but it meant we could no longer afford our old car or even got banned from entering the town center with it.But a lot people still can't afford a modern car that meets the standards.Once they finally got the money and car the laws change again and they need yet again a newer car.This created a huge export and recyling market and profits for other people though.And what differenc did it all make in reality?While we were forced to improve and lose money countries like the US refused for years to even consider reducing the pollution.Countries like China and Russia even increased their pollution to impossible levels.We all remember how Bejing was literally shut down for the Olympics so the athletes have a chance to survive the games...We know how the pollution or global warming problem is misused to make money.The governments get huge payouts in the form of taxes from those cars that can't meet the specs.The dealer smiles with the increased sales of cars.And again the government smiles too as they get taxes from this as well.We know it happened before and is still happening with everything realted to fossil fuels, global warming and pollution, so why would electricity be any different?Reactors and coal fired power plants are phased out with basically nothing to replace them.Solar and wind will provide and till then we keep what we really need to keep....There is no plan for what comes after coal and the atom.There is no alternative.Batteries need electricity.And providers will always be the middleman controlling both the price and the availability.So how does this actually work you might wonder...No matter who invents or produces a new device to provide electricity - there is a very limited market for them.A farmer can't buy a full size wind generator and place it on his land...But an electricity provider can buy thausands of them....And if you go bigger than ask yourself who would need a 10 or 100MW fusion generator?Providing electricity is only a viable option if you go big and if you can sell the excess with a profit margin.Leaves only our electricity providers as customers.If you don't have to care about the buying price because it will be put down one way or the other onto your customers than it is like a credit.Only difference is that once it is paid off you start to get money back!Imagine that for your bank account ;)And if you know what you sell can have a very generous profit margin because your buyer does not care then the solar or wind farm will be quite costly to build..."We know we are not cheap, but who else can deliver you what you need?"And like our big supermarkets there will be an agreement on what the wind generator can cost.Ressources....Be it wind, be it solar or just the modern electric motor in your car - they all require stuff that is very limited on our planet.Take Neodyminum.Without it we have no wind generator or fancy motors as we wouldn't have powerful enough magnets.Vital elements and mineral required are only available in a few spots on our erth in quantities justifying mining them.I won't make this much longer than it already is, so please look up what is really needed to keep our future solow and wind projects alive.Then go and check where we can find thes things in good quantities.Once you did you might realise why the world tolerates the abuse of human rights, freedom or just self expression in other countries ;)If only China would stop today to export and sell their rare earths and prcious minerals basically our entire production worldwide would suffer quickly.Entire industries break down quickly and prices for certain things would literally explode.The US already started to re-open long abandoned mining projects as suddenly even the most costly operations become viable again.Think about this next time you fancy a world free of cars and truck using combustion engines ;)

Topic by Downunder35m   |  last reply


Battery charger circuit?

Hi, Can someone help with a simple battery charging circuit? It is to be attached to bicycle dynamo to charge the 4 V battery. Now the power generated by the dynamo would be fluctuating depending upon the RPM. So need to build a charger that would ensure constant supply to the battery. Preferably simple and economical circuit as this would be used on some charitable work. 

Question by rahuldj   |  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


Why has nobody found a way to power a vehicle using magnetic energy? Answered

It seems like such a simple solution, yet nobody has attempted it yet. Why? The force put off by magnets is basically free energy, right?

Question by annchanted   |  last reply


What kind of alternator and gearing for a steam project?

I'm in need of some help, I'm working on a project including a steam powerer tesla turbine which I want to harvest surplus energy going into a boiler, it'll also serve as backup power generator in winter when the P.V.s slow down. I'm looking at a 2m long, 300mm dia boiler witha 100mm dia flue running through it, not sure what sort of pressures I'm looking at. This comes after a thermal mass rocket stove style combustion pipe burning wood. The tesla turbine will be ally plates in oil drum based housing (572mm, 22.5" dia). Any ideas what sort of alternator would be suitable and should I be thinking about any gearing?

Question by JohnA391   |  last reply


Magnetic Levetation? A Magnet Levitating between two Bismuth plates?

I am trying to make a magnet levitate between two bismuth plates that i made (picture 3,4,5 and 6). As you can see they are round discs about 7mm (millimeters) thick and 110 mm or 11cm (centimeters) in diameter. I bought two magnets; -the one I am trying to make levitate is 30mm (millimeters) in diameter, 10mm thick, and 22kg (kilograms) strong... -the other that is on top, the one that is pulling the magnet up is 30mm in diameter, 15mm thick and 23kg strong I put my two plates of bismuth so that there is about 25mm of space between them... Than I put in the 30mm x 10mm magnet that I want to levitate inside. The other magnet is located above the setup. I very slowly, ever so carefully start to lower the magnet. The magnet between the two bismuth plates starts to shake and at one point hits the top bismuth plate. I can't make it to levitate, either it is on the bottom plate or on the top. I tried to make the space between two bismuth plates smaller and larger, to lower the magnet by a very small amount...it didn't help... PROBLEM: I can't make it levitate, either it is on the bottom bismuth plate or on the top... WHY IS THIS? HOW CAN I FIX IT AND MAKE IT LEVITATE? Thank you for your help! -Stanislav A.K.A. Comodore

Question by comodore   |  last reply


how can i tune a received ightwave like a guitar's strings and what is the energy required per kHz?

                                                                     Is a light wave like a guitar string?  Can i take a received electro magnetic wave and tune it? For instance, can I take white light into a device and change the waves properties so that it comes out as red light, or microwave radiation? The applications could be staggerring. If, for instance, I could take incoming sunlight and tune the wave so that the output was alternating current electricity. This would seem to me to be a far better way to harness the enormous energy contained in a lightwave.

Question by tswartwood   |  last reply



I'd like to replace 2 c batteries with solar cells, to run a toy? Where can I buy the solar cells?

How much solar power do I need (do I need to measure both watts and Amps)? Where can I purchase the solar cells, inexpensively? This is for sunlight use, only. If I want to store the energy for nighttime use, also, what will I need?

Question by    |  last reply


Dinosaur wind turbine

I am in Kenya and being of a technical persuasion have been asked to fix this geriatric wind turbine. It is an electromagnet (as apposed to permanent magnet) based generator that my friend bought from the Italian scouts. I cannot for the life of me get anything more than about 3V from it. Has anyone ever seen anything like this before and if so have any idea where on earth I might be able to find out a little more about who made it or how I might be able to fix it. I have tried everything I can and still no cigars. Any help much appreciated. I am here setting up this organisation if anyone is interested access(hyphen)wind(dot)com

Topic by accesswind 


Windbelt, Cheap Generator Alternative, Set to Power Third World

Working in Haiti, Shawn Frayne, a 28-year-old inventor based in Mountain View, Calif., saw the need for small-scale wind power to juice LED lamps and radios in the homes of the poor. Conventional wind turbines don't scale down well -- there's too much friction in the gearbox and other components. "With rotary power, there's nothing out there that generates under 50 watts," Frayne says. So he took a new tack, studying the way vibrations caused by the wind led to the collapse in 1940 of Washington's Tacoma Narrows Bridge (aka Galloping Gertie).Frayne's device, which he calls a Windbelt, is a taut membrane fitted with a pair of magnets that oscillate between metal coils. Prototypes have generated 40 milliwatts in 10-mph slivers of wind, making his device 10 to 30 times as efficient as the best microturbines. Frayne envisions the Windbelt costing a few dollars and replacing kerosene lamps in Haitian homes. "Kerosene is smoky and it's a fire hazard," says Peter Haas, founder of the Appropriate Infrastructure Development Group, which helps people in developing countries to get environmentally sound access to clean water, sanitation and energy. "If Shawn's innovation breaks, locals can fix it. If a solar panel breaks, the family is out a panel."'Frayne hopes to help fund third-world distribution of his Windbelt with revenue from first-world applications -- such as replacing the batteries used to power temperature and humidity sensors in buildings. "œThere's not a huge amount of innovation being done for people making $2 to $4 per day," Haas says. "Shawn's work is definitely needed.'http://www.popularmechanics.com/technology/industry/4224763.html?series=37

Topic by ewilhelm   |  last reply


12V in, Multiple output voltages - how to?

Hey guys, BRAND SPANKIN' new here, didn't even know there was a forum until yesterday. Ok I made a instructable yesterday but it was theory and was told to post it here instead, so, yeah tah dah. amazing. What I want to do is to hook up a 12V deepcycle battery through an array of 4-5 different car adapter chargers (plug into cigarette lighters) and have variable outputs. A +/-12V in, and a 4.5, 6, 9 ,11, 12, etc (the most common) outputs wired to two outputs; a male usb/mini usb and a male plug (Protected of course). I can do that, thats just a little bit of soldering in series, but the tricky part for me is I wanted to make a switch to be able to cycle through each! How can I get a switch to cycle through 4-6 different states? I've taken some logic design, and I could probably make one using digital logic, but that is messy and requires an alternate 5V source as well. You guys have any easy ideas, or any common items that have a 6 way switch? or even how to use logic to get ONE switch to cycle through 6 states?? Thanks d00ds!

Topic by GreenD   |  last reply


Maintaining a stable voltage on a wind turbine?

Every couple weeks a new instructable comes up on some green energy thing or another, but one I am really interested in is wind.  The problem I see is that with wind ranges from 5 - 25 mph, the voltage change is extremely problematic.  When I see people putting permanent magnets on alternators for use with wind, it seems ridiculous.  Even if you are using an inefficient battery-storage off-grid system, you still need to maintain 12-15 volts to charge your battery, and an alternator is made to do that by varying the magnetic power.  Now I understand the extremes of a alternator's voltage regulator are likely fairly narrow, but still quite useful in generating wind energy.  What I am looking at is 3-5kw of grid-tied power.  This is great and all, and possible in for me, but I don't see how I could maintain a stable enough input for it to work.  Most inverters are for solar power and aren't grid tied. The next most common are grid tied solar which take 12v DC and scale it to 115 ac across three phases.  Finding a grid-tie 5kw 3 phase in and out ac grid tie inverter is extremely hard, but not impossible.  The only thing that is impossible is finding one that can handle highly unstable voltages.  So the options I am left with are using a variable transformer to bring the wind power down to 12v and then rectifying it, then pumping it through an inverter which leaves me with 70 - 80 % of the original power.  My other option is to, like a car alternator vary the rotor voltage to maintain the desired end voltage.  The one problem I see with this is that there is a large amount of potential energy not tapped.  For example lets use 1 as the relative output as well as the input to generate a magnetic field.  If the speed is 1 then both in and out are 1.  If the speed is 2 then the in will be .5 now the out should stay at 1.  But if the in had remained at 1, then the out would be 2 so essentially you are losing half of your potential energy.  This isn't a problem in cars because they aren't tapping the maximum power possible. All the time, they don't need it.  This is a problem with wind turbines, so is there a way around this?  What wold you recommend to do for grid-tied wind power.

Question by jj.inc   |  last reply


V6 Stirling Engine

I have a 4.3l v6 that came out of a s-10 pickup.  I was wondering if i could make it run on the stirling cycle? It is a 90 degree v6 so it should work, This is the only site i could think of to post this question on. I was thinking i would isolate the water jackets to the right and left bank of cylinders then heat one side and cool the other. I am good with engines and am skilled in the garage. I'm just tinkering. Maybe run a generator with it if it runs. I have a welder, plasma cutter, ect and can use them. Just kinda throwin it out there...

Question by qparker   |  last reply


Options to improve cooling and reduce consumption for portable coolers

I recently had to start learning how to service airconditioners on the fast and that learning got me thinking about my portable coolers.... Some of us like to go camping or on longer fishing trips, so there might be one of those 3-way fridges in use or a better cmpressor model. The one thing they all have in common is that they can only cool down to a difference in ambient temperatures. No matter which way we turn it the cooling produces heat and that needs to get away somehow. The other big thing is the cooling cycling - or the lack of it on a warm day. After some reading and thinking I came up with some ideas that might be applicable to your existing cooler if you are willing to mess around a bit. Let's start with the produced heat, shall we? Down here in Australia most people either have the fridge in their4WD or camper. In a car or small camper trailer there is often the problem of airflow, so the cooler might be doing overtime for no other reason than a lack of airflow. If you check online sites like Amozon and Ebay you quickly find fan systems meant to be installed inside the cooler to get lower temperatures and a quicker cooling of fresh goods. The thing is that the box is quite well insulated and the benefit of the airflow goes only as far as it can reach. And even if the box is quite empty and you would have a benefit of the cold air moving around it won't change the fact that "improved" cooling always comes with more heat in this case. But if we use one of these fan systems to actually improve the airflow on the hot side we not only get better cooling but also a reduce power consumption - something worth considering if you have no backup power generator.... This of course brings us to placement. As I have done the mistake myself you might be tempted to put a 3way cooler onto your seat. Opening it with the back free means the lid always gets stuck on the seat, do it the other way around and you block the airflow. If you do put it on the seat then make sure two things match: 1. The thing is secured properly. 2. The airflow from your aircon is able to reach the hot side of the cooler. Even permanent installations in a camper benefit from a good airflow. Often the fridge or freezer is built into some sort of bench and the airflow behind might be very limited. A simple solution here is to add a vent on top of the bench to allow the hot air to escape. A better one is to use a fan that is powered together with the heating element or compressor and drives the hot air to the outside. How to improve the cold side of the box or fridge? Well, to be honest there is not much that can be done unless you are prepared for some serious work. Depending on compartment size, contents and how full it is a little fan can help to keep the temperatures even but it won't help to get it cooler or reduce the cycling periods for the cooling. The only really working way that I found is to use a "battery" for the storage of the cold. The cooling works by checking the inside temp of the box and if above the set temp the cooling won't stop. This is all well and good while we have a constant supply of power but once we are on batteries it would be great to keep the active time to a minimum. A working solution is to build a container that fits around the cooling element. Smaller types often use an aluminium heatsink, bigger types might come with a compressor and an evaporator. In either case proper sealing is important! Most good models are fully waterproof, meaning even if you would fill them with water they would not leak in other areas than the door. But double check and if in doubt use a bit of silicone to make sure. Ok, but how do we "store" the cold coming from the device? Cold packs ;) These things contain a ready to use mix that holds cold temperatures quite well. Another really good alternative is alcohol or radiator coolant, although the last has limited capabilites in terms of holding capaity for the cold as it is desinged to exchange heat fast rather than to keep it. With a suitable sized and sealed box around the active cooling element we will need longer to actually see any cooling happen (with a warm "battery") but that can be compensated for by good planning or a frozen water bottle. If the cooling element is covered with a box of cooling gel then it has to cool this first before anything happens inside the box. But once it does the pack is already far below the normal temp it would have during normal operation. Remember the inside of the cold pack cools down first before the outside will get cold ;) So once the set temperature is reached the device will shut off. But since the cold pack is far below the set temp it will continue to cool our box until the core is warmer than the set temp. Quick thinkers will now say the benefit is lost as the time required to cool the "battery" down again is much longer than the normal cycle time - and they would be correct. But as we get much colder temps inside the gel box the overall running will still be less compared to normal operation. And since from the second cycle on the gel is only warming up to operating temp of the box it will be much faster than with a warm box. Another benefit might be the ease of cleaning and ice removal. Some peltier driven coolers have big cooling fins or a quite bad design for the heatsink allowing mould to grow where you can't remove it easy. If the box is made from stainless steel and flush with the back wall of the box we won't have that problem anymore. Ok, but how much is good or too much for the size and gel content? You got me there as it is bit tricky. You don't want to loose much usable space for starters and you don't want to wait hours for the gel to cool down if the box was not used. IMHO the size should fit the cooling element with about 20% to spare all around. If stainless steel is not an option than aluminium is the next best choice. Thin sheets can either be be cold formed with a hammer or "brazed" with a good torch and the right rods. Ok, before that route is there anything I should consider or do first? Depends ;) 3-way systems usually use a flame or heating elements to heat an ammoia solution. After years of neglect corrosion can form and reduce the amount of heat transfered into the system and reducing the efficiency this way. It might help to take the heating elements out once a year or so to clean them and the contact areas from any corrosion or dirt build up. With a fixed shedule for this you won't have the problem of never noticing a badly corroded heating element either - and this is the main failure on these systems.... Modifying your camper or making a few mods to your 4WD drawer system is not for the faint of heart and should be done with consideration. The last thing you want to do is rush things to find out it was not necessary. Before cutting holes check if you can't find the room for the fan in a different spot and use ducts to control the airflow - sometimes it is easier to blow air in than to get air out ;) When it comes to creating vents or connections for air to the outside always make sure it is waterproof and insect safe! If you can let the outlet go downwards so water won't run in, for 4WD trailers consider a flap to prevent water from going during a river crossing. Flyscreens will not only prevent insects from coming in but on the inside also prevent dust to go eerywhere - allow to the removal and cleaning! The salts used in these cold packs can be corrosive, so you have to make sure there are no leaks and that there is no steel to come into contact with gel - this includes screw ends hidden in through-holes. If in doubt use a coat of paint but keep it as thin as possible. Even on peltier systems it might be impossible to remove the heatsink without massive surgery on the internals. So before you take it all apart to gain access check if it is far easier to seal around the box opening and possible screw connections using silicone. The cooling battery can be screwed on and sealed with silicone as well as an easy escape route. Although for this to work you need to check if the material of the box allows for a proper bond with the silicone! Some materials just won't allow anything to stick at all, even after sanding them. So do a test first in an area where you would be able to cut the silicone away without causing damage. If you can rip or peel it off the surface you should not try to use a cooling battery screwed to the wall, only use a box that is fully sealed with the cooling element and has a seperate back - one complete unit around the cooling element. I have a 3-way system with a freezer compartment that does the cooling for the fridge too - what can I do? These units either provide good freezing with the fridge temps too low or good fridge cooling with no freezing capabilites - depending on the thermostat used. Our problem is that is next to impossible to add a cooling battery of the normal kind to these systems. The L-shaped freezer box can really only be added with a L-shaped cooling battery from underneath. Only if you don't need any freezing at all you could add a cooling battery to fit into the freezer box shape. In either case the benefit is somehow limited by the way the thermostat is used. If there is no temp control for freezing it should be fine. Warnings... Only peltier driven coolers are free from refrigerants. Every 3-way or compressor system uses refrigerant as evident by more or less piping and heating elements. Never attempt to screw anything into a cooling element containing refrigerant! Even if you think between the channels all will be fine it won't be! The material is just pressed to form the channels and any damage caould mean refrigerant leaking out! Use silicone instead and make sure all surfaces are properly cleaned before applying it, also wait until the silicone is really fully cured before putting any stress on it. As said, these cooling gels can be corrosive, especially if DC voltage is involved. Make sure that everything that is not aluminum or plastic is properly sealed before allowing ongoing contact with cooling gels. Do not attempt any of this if you have to ask yourself what tools you might need or how make a suitable container for the gel. If in doubt check Google on how to work with aluminium or stainless steel if there are not enough Instructables for it. The gel will expand a little bit if it freezes, this no problem in a metal container if you allow for a bit of flex or on the side added strength  - whatever suits you better. Another option is to get a few different cold packs (by the active ingredient) and to do a check in a little container. Freeze it and note whe level cold and warm. Little to no difference means nothing to worry in terms of expansion during freezing.

Topic by Downunder35m 


What is the best way to to turn 24 volts dc into 14.4 volts dc?

I want to make a power supply for my laptop so I can use it for long time while camping.  I want to use car batteries.  I have tried using just one car battery but this does not work.  A car battery varies between 12.6 volts and 0 volts.  Most of the energy is gone by the time it gets to 10.5 volts.  An inverter is designed to be used when a car is running.  The alternator generates 14.4 volts so things which run off of a car alternators operate at 14.4 volts.  When I plug my laptop into an inverter which is connected to a car battery sans the car it will only work for a few minutes.  The voltage of the battery drops when current is being drawn from the battery.  This sets off a low voltage alarm on my inverter.   So new plan is to hook up two car batteries in series running at 24 volts.  This brings me to my question.  What is the best way to convert the battery power to a regulated 14.4 volts.  The battery will be 25.2 volts fully charged and will drop all the way to zero when dead if you let it.  Most of the energy would be gone by the time the battery gets 20 volts.   The set up will be 24 volt batteries---14.4 volt regulator---inverter---laptop

Question by Noblenutria   |  last reply


Power Sine Wave Circuit

Hi I am trying to build an economical circuit to power an AC electromagnet. The energy source has to be a battery, preferably less than 24v. The power draw of the electromagnet will be about 500W (the application requires a high-power alternating magnetic flux). I'm thinking of making a sine-wave generator and a simple transistor amplifier with high power transistors. Can anyone suggest circuits for this? My knowledge of electronics is not that great, but I'm quite enthusiastic about this and I believe I can give it a try. Any help will be appreciated. Thanks R

Question by Richy33   |  last reply


Best &quot;HHO Electrolyte&quot; Versus &quot;Conditioned Water&quot; and Why you think it is ?

I eared many things about hho generator but some say it is better to use "solution recipes" (electrolyte) instead of  "conditioned distilled water" . I'd like to know more about conditioning distilled water . I need your help on this one ! I plan to use rectified high voltage for 2 dry cells . 8" by 8" 16 plates each using microwave parts but I can't figure the minimal input if coming form  12 volts batteries and car alternator . I bet I'll need a converter from car DC to H/V transformer and I have no idea how to make it a reality Use the best of your knowledge to answer !!! Instructive and useful links are welcome ...

Question by wiseboy   |  last reply


I realize this (CNET mention of Instructables) is old news and it was probably posted when it happened...

But as long as I have been going to CNET's site, this is the FIRST time I have seen this: Instructables link from CNETMaker Faire: CNET visits the tech DIY show MEET YOUR MAKER.(4/21/2006; updated 4/28/2006)Are you a compulsive tech tinkerer, a closet MacGyver? Do you wish science fairs weren't just for students? Well, now there's an event for you: the first Maker Faire, where backyard inventors show off their projects and demonstrate how you can build them, too. CNET's on the scene, checking out the fashions, the music, the gadgets, the robots, the tech running on alternative energy--from steam to biodiesel to, yes, trampoline--and, of course, the homemade rockets... Turning a VCR into a cat feeder....Dinosaur sitings !

Topic by Goodhart   |  last reply


Wind Power Charge Regulators

Hello!! I need some help here...I am very "green" when it comes to alternative energy, so bear with me please! I recently decided to put together a small wind generation system to power my workshop. System is comprised of a 38v Ametek PMDC motor, 6.8' tri-blade array for propulsion. I also intend on installing a 2000 to 3000 watt modfied sine wave inverter powered by my battery bank to provide AC voltage to the shop. I want to be able to used the majority of the power created by my wind generator. I understand the concept of using a "shunt" but do not have a need for hot water or useless lighting. My question is this, would the Flexcharge NC25A charge controller (www.flexcharge.com/flexcharge_usa/products/nc25a/nc25a.htm) be sufficient enough to used in this system? Or is there something else out there that would maintain my battery bank without shunting the load when the bank is fully charged....Thanks in advance.

Topic by NMCBDet23   |  last reply


Record Solar Powered Flight

UK-built solar-powered plane has set an unofficial world endurance record for a flight by an unmanned aircraft.The Zephyr-6, as it is known, stayed aloft for more than three days, running through the night on batteries it had recharged in sunlight.The flight was a demonstration for the US military, which is looking for new types of technology to support its troops on the ground.Craft like Zephyr might make ideal platforms for reconnaissance.They could also be used to relay battlefield communications.Chris Kelleher, from UK defence and research firm QinetiQ, said Unmanned Aerial Vehicles (UAVs) offer advantages over traditional aircraft and even satellites."The principal advantage is persistence - that you would be there all the time," he told BBC News. "A satellite goes over the same part of the Earth twice a day - and one of those is at night - so it's only really getting a snapshot of activity. Zephyr would be watching all day." The latest flight was conducted at the US Army's Yuma Proving Ground in Arizona.The Zephyr flew non-stop for 82 hours, 37 minutes.That time beats the current official world record for unmanned flight set by the US robot plane Global Hawk - of 30 hours, 24 minutes - and even Zephyr's own previous best of 54 hours achieved last year.However, the Yuma mark remains "unofficial" because QinetiQ did not involve the FAI (Federation Aeronautique Internationale), the world air sports federation, which sanctions all record attempts.The US Department of Defense funded the demonstration flight under its Joint Capability Technology Demonstration (JCTD) programme. The 30kg Zephyr was guided by remote control to an operating altitude in excess of 18km (60,000ft), and then flown on autopilot and via satellite communication.It tested a communications payload weighing approximately 2kg.At first sight, the propeller-driven Zephyr looks to be just another model aircraft, and it is even launched by hand. But this "pilotless" vehicle with its 18-metre wingspan incorporates world-leading technologies.Its structure uses ultra-lightweight carbon-fibre material; and the plane flies on solar power generated by amorphous silicon solar arrays no thicker than sheets of paper. These are glued over the aircraft's wings.To get through the night, the propellers are powered from lithium-sulphur batteries which are topped up during the day."A lot of effort has gone into power storage and light-weighting the systems," explained Mr Kelleher. "Lithium sulphur is more than double the energy density of the best alternative technology which is lithium polymer batteries. The engineers from the Farnborough-based company are now collaborating with the American aerospace giant Boeing on a defence project codenamed Vulture.This would see the biggest plane in history take to the sky, powered by the sun and capable of carrying a 450-kilo (1,000lb) payload.US commanders say the design must be able to maintain its position over a particular spot on the Earth's surface uninterrupted for five years. QinetiQ is the public company that used to be the British Government's military research department, before they privatised it.BBC articleQinetiQ's page on Zephyr

Topic by Kiteman   |  last reply


Can I hook a 3v solar panel up to charge a 3v lithium coin battery to keep a 3v chip led going?

The project is to light up the inside of a shadow box.   Currently I have a 3v 20ma chip led that is plugged into a 3v lithium coin battery ( CR2032) with a switch in between and that all works out fine.  My math figures that should get me maybe 5 days max of light for one chip led.  Which led me to thinking about a solar panel instead for the top of the frame for something that might last longer.  I'm looking at the PowerFilm MP3-25 Flexible Solar Panel 3V @ 25mA right now, but I think if I just do that, at best it only lights up with the lights are on and bright enough in the house if I use that in place of the battery. I'm kinda new to all this, and I'm trying to figure out is there a way I can hook the solar cell up to the coin battery holder to charge the lithium battery so it can use solar power or the battery or so it is always charging the battery?   My guess is that's a bad idea without something to cut off the charging once the battery is full.  Also, I don't know if that would fry the chip led because that would then be 6v coming through rather than 3.   I also think I read I would need something with slightly higher volts to charge a 3 volt battery. Also, to back track a little, the reason I'm using a coin battery rather than AAs or a 9v and a resistor is because I can fit the coin battery nice a flush with the back of the picture frame and it still hangs nicely, and leaves enough clearance for the power switch to stick out just enough that all you have to do is press the frame to the wall to turn it on and off.  Which gets us to if a solar charger could charge a coin battery, I'd still want to pull it off without extra circuitry on the back for the clearance reason (it's maybe 3/16" clearance at best).  Without adding a lot in parts, would it maybe be possible alternatively to make a flip switch so one position is using solar and the other is using battery?  If it was just adding the solar panel to the top and flip switch on the side, that would totally work.  I just can't find any info for something this small yet. Thanks for any info anybody has. ** EDIT Did some more research and I guess you can't recharge just any old C2032 battery.  But there are some that are rechargeable.  Amazon has these.  http://www.amazon.com/Battery-Li-Ion-Rechargeable-Button-LR2032/dp/B0058E94O6/ref=reg_hu-rd_add_1_dp So the question is still can I just hook a solar cell up to this battery terminal and have it basically just trickle charge?   Here's the coin battery holders I'm using.  http://www.modeltrainsoftware.com/3v.html It looks like the way they come before they are wired up is they have a third prong coming out that they clipped off for this version.  At least from what I've seen sold on other sites that isn't per-wired.   No idea what that prong does or if that would be needed for charging. Also, I'm trying to follow this instructable but it seems to skim over a lot of things, or at least the details.  Sounds like maybe I need a rectifying diode and dpdt switch is what I'm looking for?   I'm trying to read up on the dpdt switch but I don't really fully understand what it does in this case.   The diode I get is for making sure the solar panel doesn't suck energy back out of the battery when dark.   Is this the right track? **** Edit Kept searching.  Are Super or Ultra Capacitors an option for something like this over the battery?  Just use that with a solar cell?

Question by technicallyartistic   |  last reply


How to make indoor lightning with Led Strip + Battery + Solar Panel?

Hello everyone, First thing first. As you know im new to this =) However, im familiar with wiring & soldering some easy parts. I will try describe my problem detailed as possible for future readers with same problem. My Grandmother living on a top of mountain for like 5 months in a year. As you gues, there is no electric. So, i decided to give her indoor lightning with solar enegry and led strip for at least 2-3h in a day. Place where she lives is mostly sunny. I can say thats about full sunny 3 months of 5 and semi-sunny or cloudy 2 months of 5 in total (There will be no autumn or winter usage). I'm not planning to use 5m of strip at one connection. There are 4 rooms in the house. I'm thinking 9 leds (or 12) in each rooms. Lets say 12 for fixed amount talk. That makes 12 x 4 = 48 leds in total. If light would not enough for her, can consider increase led numbers 24 in each rooms. Also dose not excepting light from leds as normal lightning. Just wanting she would be able to see whats around. My plan was simple before starting seacrh (LOL). 1 or 2 entry level solar panel(s). A backup battery (Li-Ion) charged via solar panel. And leds. So, things were not gone as expected of course. I had searched like 5-6 hours about this in past 3 days. I had read every similar situations (or a part of this) that i find on here or somewhere else (other forums). Situations was different all the time. But, i learned a lot. And this is not enough yet. I have learned there are a few types of 12V strip led (Do not remembering the link, sorry). But those are; 2835, 3014, 3528, 5050 and 5730. If i did not get it wrong, when number goes down brightnes goes down too. But, energy consumption goes down too. There are a few things about led strips to know: There is a Power Consumption number for all leds. But, that is not means all 5050 leds will consume same amount or other numbers. And its important about feeding your led strip. It depends on brand or manufacturer. If i didnt get it wrong (again). If you feed your led more than its required Voltage, it means you are grinding its life cycle. It will gonna die faster than normal life time. That is also causing overheat on leds strips. However, not sure if its life time will be longer than normal if you feed it with less Voltage. Forexample; feed 12V led strip with 11V. Did not see anything about it while searching. And last thing that i have learned about leds while searching is, led strips can be different on led numbers on them. Mostly (that i had read) they are 2 types on number. One is 60 leds on 1 meter and other on is 30 leds on 1 meter. I have learned realy a lot about Li-Ion batteries at this link https://www.e-cigarette-forum.com/forum/blog-entry/9-battery-basics-for-mods-the-ultimate-battery-guide.4848/ I have learned "do not over voltage your leds" and alternative methods in theory at this link http://electronics.stackexchange.com/questions/135611/what-happens-if-i-supply-18v-to-a-12v-lighted-switch I have learned "sometimes exact V is not enough when using solar panel" at this link (still confused about DC Booster part about will i need it or not) https://www.instructables.com/answers/Why-can-I-recharge-lead-acid-batteries-with-solar-/ I have semi-learned "how to calculate Watts, Amps etc" at this link http://diy.stackexchange.com/questions/18225/what-do-i-need-to-install-led-strip-lighting I have learned there is a "Ohm's Law" and calculate/use it at this link http://electronics.stackexchange.com/questions/117594/how-to-get-12v-5amps-battery-setup-for-led-strip I have consolidated my new infos at this link https://sirs-e.com/general/battery-powered-led-strips/ I have learned, that i can improve my batteries capacity or voltage (or both same time) with series/parallel connecting them at this link https://www.batterystuff.com/kb/articles/battery-articles/battery-bank-tutorial.html And few more links via links at above including i have learned there is a battery type 12V named "Lead Acid Battery" and variations of it. I chose parts at below aka my simple plan (LOL). Batteries (not all of them, need to decide which one. Batteries chosen via Li-Ion battery explanation link at above): 26650 5200mAh 3.7V High Capacity High Drain IMR Li-ion Orbtronic Battery -  http://www.orbtronic.com/26650-5200mAh-IMR-Li-ion-battery-orbtronic Panasonic NCR18650PF 18650 10 Amp. 2900mAh Hybrid IMR Li-ion Rechargeable Battery - Flat Top - High Drain -   http://www.orbtronic.com/batteries-chargers/high-drain-18650-2900mah-ncr18650pd-hybrid-li-ion-rechargeable-battery-panasonic-flat-top Solar Panels: 220x200mm-12V-5W-Solar-Panel-Fit-Car-Battery-Trickle-Charger-Backpack-Power http://www.ebay.com/itm/220x200mm-12V-5W-Solar-Panel-Fit-Car-Battery-Trickle-Charger-Backpack-Power/141777113443?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D777000%26algo%3DABA.MBE%26ao%3D1%26asc%3D36144%26meid%3Da11bbdc4faa8438bb298191c9d100913%26pid%3D100009%26rk%3D1%26rkt%3D1%26mehot%3Dag%26sd%3D221887501129 10W 12V Polycrystalline Cells Solar Panel Poly Battery Charger Power Generator http://www.ebay.com/itm/10W-12V-Polycrystalline-Cells-Solar-Panel-Poly-Battery-Charger-Power-Generator-/221887501129?hash=item33a9869349:g:za4AAOSwVL1V-TGi Now, i need your help and advices. Because, after all reads, King-Kong is still jumping in my head. As i described before; i want to use a (or two) solar panel(s) and charge batteries then use batteries for light small led strips. All led strips should be connected together on one circuit from batteries. Ofcourse there will be small switchs in each room to lit on/off led strips. 4 x 3.7V Batteries makes a total of 14.8V or 3 x 3.7V batteries with 11.1V will do the job too? Can i connect 3 batteries in series and parallel for improve capacity and voltaj? If possible, prefer to use batteries in day time too. Not for long day time or load. I gues like 5-10 mins in day time for dark rooms. Detailed explanation or step by step guide link would be freaky awsome. I have learned many things while searching but in theory. As you know im all about strange to terms. And there will be few future readers like me too i believe. I'm sorry about my English and long links. Do not know how to shorten them. Best regards, Mehmet

Question by signOnthe   |  last reply