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dynamo working?

Working principle of bicycle dynamo

Question by antony05    |  last reply

Help with Dynamo types

I have a question for everybody out there. It has been a very long time since I did this type of electrical design work, and for the life of me I can’t remember the principals. I know there are many different ways to generate electricity by using mechanical motion, and converting a motor into a dynamo is very easy. What I am trying to do is to make a brushless dynamo. I have taken my inspiration from a cheap hand cranked torch, and intend to improve on it a lot. In this torch it has a coil which has a flat disk magnet sitting above it. The magnet is spun creating the charge in the coil and is used by the LED's in the torch. What I want to know is how specifically the voltage (potential difference) is created in the coil. My experience of stationary coils is where the magnet is rotated inside the coil. Could someone please explain it to me? Many thanks.

Topic by Batdragon    |  last reply

Bike dynamo help!

I figured out how to make a bike dynamo.  How can I use the power it generates to charge a 12V battery?

Question by Kid Ninja    |  last reply

Dynamo powered TV

Hi All, Im not sure what to search for or where to begin with this idea and was wondering if anyone can help me. My wife is always adamant to lose weight and buys random exercise machines (bike,treadmill etc.) These last for about 2-3 weeks then she gets bored of them. She has asked for my help in trying to get her motivated so i have devised a plan. muhahaha She has said that her exercise will consist of her in front of the TV at night rowing away (she just got a new rowing machine again). so my plan is to snip the plug of the TV connect this to a 240 volt relay that i can connect to the arduino and at a set time the arduino will turn of the relay switch until extra power is brought in by the dynamo on the rowing machine. the relay will start at 8pm and turn off around 6am in the morning.   A bypass switch will be added to allow the relay to turn on for 30 mins as we have a small child and she doesn't want to sit rowing whilst watching TV trying to get him back to sleep whilst feeding him a bottle. My question is would this be possible and what stuff would be needed to make a dynamo on to the rowing machine? also can a arduino be programmed to do something with a small input of electric?  Also this idea has been agreed on by my wife.

Topic by nats0128    |  last reply

Contactless Dynamo / Generator

Hi all,I am wishing to add some sort of dynamo to my bike to power lights. The main reasons are if the batteries get low I will forget to change them, and I will probably forget to turn the lights on. So off I went to eBay and bought a £4 generator and light set. It arrived and today I have been attempting to fit it - to no avail. I have a mountain bike with full suspension so there is no where suitable to fit it to.So back to the drawing board. I came across FreeLights. The idea itself looks promising (unlike their spelling), however their implementation probably wouldn't be any good for me as it appears to be aimed at thin framed bikes - hacking probably could be done, however I would like to roll my own solution, and create an Instructable in the process!So anyway, if you are too lazy to read the webpage above, here is how it works:- A magnet is attached to the spokes- There is another magnet in a container- The container has wires around it- The container connected to the forks so the magnets brush past itBasically it is like a cycle computer sensor, but it produces lots more electricity! I like their idea, but it seems rather inefficient as the magnet is just randomly spun hoping for the best. They offer a kit version which appears to use a spherical magnet, but even so it still seems rather inefficient to me. So on to two other possible options. The first is basically the same idea, but the magnet is fixed so it can only spin in one plane. Something like this [Ultra-simple Electric Generator]. The other option is to get rid of the spinning magnet, and instead just have coils like the various wind turbines on this site.So basically I want to know which method is the best, and given that how I can maximize the power produced. I am thinking just increasing the number of turns, stronger magnets, greater number of magnets on wheels, greater number of 'generators' etc. And then realistically, what sort of power I would be able to get?Cheers, Luca

Topic by TheLucster    |  last reply

Charge battery with bike dynamo

Hello, I would like to charge a battery using my dynamo on my bike. The battery I would like to use for my head and tail light for example and for charging my phone. Would this be possible and how? Thanks in advance

Topic by doppiej    |  last reply

Charge batteries with a bike dynamo? Answered

I am experimenting with ways to charge batteries while cycling. Standard bike dynamos produce 3 watt 6 volts.  That's not a lot of power but 12 hours of cycling should charge a 36 watt hour battery.  I am thinking about about making my own battery pack.  It needs to be 4s1p 14.4 volts.   What I need help on is what sort of battery chemistry to get: lithium ion, LiMiNi, lithium poly, etc.  The batteries I need should charge efficiently at low current (about .25 amps).   The other thing I need help with is how to turn the dynamo power into charging power.  I know I need to rectify it and smooth it.  I have heard about Zener diodes.  They are used in solar applications because they are more energy efficient.  Should I use those? Lastly, dynamo power varies depending on the speed of the bike (Between 0 volts and 12 volts.)  Lithium ion cells need a 4.35 volt charge.  Would it be better to use a regular voltage regulator you get a radio shack or a switching voltage regulator.  I have an anyvolt 3.  Maybe there are PCBs you know of which automatically regulate a vacillating input voltage. 

Question by Noblenutria    |  last reply

flashlight led solar dynamo

I want to make or buy a solar and dynamo led flashlight. it should have at least 5leds and it must not be big. any ideas to help me? I found some dynamo led flashlights and some solar led flashlights, the only solar and dynamo led flashlight that I found was too big.

Topic by __-_-_-__  

bicycle dynamo to power AC outlet?

I'm thinking about scavenging a motor from a sewing machine to use as a dynamo for a bicycle. Assuming the motor is powered by ac, it will also produce ac, correct? Would it then be possible to simply wire in a regular wall outlet to the motor, and say, plug in a wallwart for charging batteries? I realize that it would be underpowered for the most part. My question is, is this just a really really stupid idea, or could this potentially work?

Topic by ericrasmussen  

how to make a dynamo battery charger? Answered

I settled on using my old drill as a generator but the power just goes into the drill instead of the batterys do i need a diode and what sort? by the way the drill is 12.5v

Question by sharlston    |  last reply

Problem in making a voltage regulator

Hi everyone! I have a dynamo on my bicycle which can generate AC 12v-30v during normal to fast cycling. I want to power electronics and charge batteries with the dynamo but do not know how to limit the voltage to around 12v DC. Any help would be greatly appreciated.

Topic by sirajmunir    |  last reply

what electronic projects can i do with an old tape recorder parts and a working cell phone? Answered

Can i do a battery charger with them ? Can i convert a dc mortor into a powerful dynamo ,if no then please explain me how to make a dynamo easily with easily available parts which can charge a nine volts battery.also tell me how to use a digital multi meter [i.e measuring resisters,diodes,transisters ect]. pls answer me all these questions

Question by vamsi srinivas    |  last reply

knowledge about wire which use in solenoid?

I want to make a solenoid & i am confused because i don't know that which type of wire is use which no or ohm . Actually i have a project in which I want to produce electricity  with the help of magnets or solenoid . So can u plz guide me this matter very gently  Thank You Ashish Dhiman

Question by adhiman2    |  last reply

What is the maximum amount of electricity that can be derived from a dynamo? (size, specs, no bar)?

What is the maximum amount of electricity that can be derived from a dynamo? (size, specs, no bar)?

Question by VCool123    |  last reply

Can we use a remote to control a dynamo?

We are making a water pump using dynamo.

Question by warcraft    |  last reply

What kind of diode(s) do I need?

I am trying to make a device that uses a dynamo. (hand crank) The dynamo when cranking produces up to 12v which I want to use to charge a battery. The problem I'm having is that the current goes both ways. When I'm not cranking the dynamo, the battery turns the dynamo. I need to make the current only go one way, only towards the battery. From what I understand, I need a diode. The problem is, what kind of diode, and how do I wire it in my circuit? Any help would be much appreciated.?

Question by corsair130    |  last reply

How much power is generated by a motor when we rotate it?

For a special project, I need a dynamo but I can not found it,because I belong to rural area.So I want to use dc motors instead of a dynamo,but how much efficient is this I don not know.Please tell me how much power is generated by a 500 watt motor.How to find it?

Question by kkp7649    |  last reply

How to store electrical energy

Hi,    I'm planning on making a windmill in our backyard since it's usually windy.  My problem is how to best store the electrical energy generated by the windmill for later use.  Any suggestions?  Thanks.

Topic by pinoymale    |  last reply

15V bicycle dynamo to charge Tekkeon MP3450

Hello, Is it possible to get 15V from a bicycle dynamo to power a charging device such as Tekkeon MP3450. With the provided solar power adapters Tekkeon requires 15V to charge itself:;=10&keyword;=solar I'm thinking this would be very useful for bicycle touring where I can charge Tekkeon while biking and charge my devices in  the evening.

Topic by turgan    |  last reply

I need some help with dynamo generator..

After stumbling upon the project at i decided to try it out first small-scale using just one magnet and coil in my hand connected to a multimeter.  Hoewever, i had no success.  I was only getting .01 (a hundredth of a volt) and I tried all kinds of ways swiping the magnet past the coil and just couldn't figure it out.  I still don't know what I'm doing wrong.  Im using the same hard drive magnet and a 5 volt relay coil.  If you have any suggestions, thanks in advance/

Question by jules15    |  last reply

one motor shaft connected to a dynamo and dynamo power we can used to rotate that same motor? it is possible or not?why?

One 12v dc motor connected with a battery and its shaft is connected to a dynamo,by using  the dynamo power we used to charge the battery and we can able to continue the process with out charging the battery using external power?why?

Question by akhilbhaskaran    |  last reply

How can you make a dynamo. . . and if you spin a moter does it genarate electricity? Answered

Wanting to make a mini windmill and was wondering if a small rc car moter can be changed into a dynamo or if not how you can make one for cheap

Question by dunc_kill    |  last reply

Dynamo charging charging circuit for AA NiCd/NiMh? Answered

I've just got hold of a Union 6V 3W dynamo with lights. I'd like to charge 4/5/6 x AA batteries during the day then switch to the batteries for the lights at night. I'm switching out the old bulbs for LEDs. Any pointers or relevant 'ibles would be great. Thanks in advance people.

Question by ZdEEvO    |  last reply

Is this a capacitor or a battery? Answered

In regards to my "battery free bike light".   I was told that a dynamo flashlight charges a capacitor.  Is this the case? Take a look, Thanks

Question by onrust    |  last reply

grid tied bicycle generator

2 questions about grid tied bicycle generators: 1/ will they feed into the grid if voltage is lower than the grid voltage? 2/ could you connect several bikes to one inverter to feed into the grid? thanks?

Question by gouldy    |  last reply

Bicycle iPod dock

So here's my idea: I'm restoring an old bike and there's a spot for a fake gas tank to go. I will build this tank, but one side will open up and hold within it an iPod dock. At least, I'd like it to.  I'm thinking of using the pedals as a dynamo crank which would power the iPod and play music through speakers mounted on the handlebars. I've been doing a lot of research and it seems possible, however, I've not done something like this before and I was wondering if anyone would have any pointers on how to make this work well. P.S. A separate USB port would be cool as well, so that a phone could be charged while riding the bike.  Thanks for your suggestions!

Topic by SamSkellington  

how to recharge a battery of 12V using a dynamo give 9V? Answered

How to recharge a battery of 12V ? I am trying to recharge a battery of 12V using a dynamo.Can I use a dynamo of 9V to recharge the battery of 12V? 

Question by tarz_00    |  last reply

What gauge is best for a Dynamo generator and can it work with a magnet from a hard drive? Answered

I am try to make a dynamo generator and i am new to this. I dont know what gauge of the coil to get if it will work on a hard drive magnets

Question by tobyscool    |  last reply

What is the best way to turn 6 volts ac from bike hub dynamo into 12 volts dc battery? Answered

I have a bike hub generator and normally you use them to run 6 volt lights but I have 12 volt lights and a 12 volt battery.  I need to change the ac from the dynamo into dc and change the voltage from 6 volts to 12 volts.  I hope in this way to have a bike which will never need to be recharged from mains, as long as I use less electricity than I make from the dynamo.

Question by Noblenutria    |  last reply

How can i make this simple dynamo, please help? Answered

I have; lots of led lights watch batteries (rechargeable) crocodile clips 10v 1000uf capacitor, 16v 1000uf capacitor and a 50v 2.2uf capacitor Lots of motors ranging between 3v - 12v on off switches 2 pin how can i make a simple dynamo circuit so that when i spin the motor with my hand it can store the charge in the capacitor or the battery, so that when i flick the switch to on the led will light without me having to spin the motor, please help i am new at this stuff. a circuit diagram would make it easier for me too :)

Question by connorfrancis    |  last reply

Can someone advise how to measure output from a bike generator/dynamo ?

This is the type that clamps onto the seat stay and is meant to rub the tire for the generating action. It's labeled 12V, 6W, Made in Japan. Two terminals, H and T. I've hooked it up to a meter and the only setting that gives me any sort of reading is AC volts with either H or T and to what I assume would be chassis ground. That gives me between 3.7 and 4 volts when I spin the unit with a cordless drill. Is this thing functional or not? And what would be proper wiring connections for it? Many thanks!

Question by ceckert    |  last reply

Exactly what components do i need to charge a bank of our four (or however many it takes!) 18650 batteries {we will be using a dynamo} with an LED to show that the batteries are being charged ?

(if needed ?)Hello & Good day to you all, Me and a friend have plans to build a miniaturized 'Rolling Road' platform for our RC 1/10th scale nitro cars!! What we both agreed on is that the Rolling Road platform is to be made out of acrylic and using skateboard bearings and other hardware, but we are completely stuck, we have an idea to add lights to the platform, the kind of cold-cathode tube lights that are for inside-pc-use... We want the tube lights to run from a rechargeable battery bank from the Rolling Road but incorporate a charging system "built-in" to the platform and a system based on renewable energy because as our cars are nitro powered, they will be turning the rollers of the platform for many hundreds of thousands of times and we wanted to harness that mechanical energy to charge the battery bank - in turn to operate the tube lights! We are both ok the structural aspect of building this rolling road platform but dont know where to start on fabricating an electronic set of components culminating into a sustaining system that produces (almost) free energy! The system must be able to run 4 sets of these tube lights, each tube light set is comprised of 2 tube lights each, so 8 tube lights in total ! The tube lights are rated at 12 volts. What our dreams are : (lol) - The system must collect the electric being made to charge a battery bank, - The system must have an LED 1 to only show the battery bank bank is being charged, - The system must have an LED 2 to show that the battery bank is fully charged, - ALSO ! if at all possible, include a simple row of 6 or 7 LED's (LED BANK?) to indicate how full/empty the battery-bank is & - Lastly, there must be a switch to switch off the circuit that charges the battery bank (when batteries are fully charged !) Ingredients: (what we DO have, lol) 20 x 18650 batteries Plenty of spare motors Lots of different grades of wire soldering skills a few switches 10 Pairs of 12v PC Tube lights (Both 4" & 12" ) Small to medium range of "ON Semiconductors" (Voltage Regulators) Max Input Voltage is 40v of one of these! What we dont have: - Knowledge of electronics! - LED's - Capacitors (if needed ?) - Resistors (if needed ?) - Transistors (if needed ?) - Semiconductors (if needed ?) - Diodes (if needed ?) - Help ! Please please please could anyone help us to even roughly 'sketch' a set of components that we could solder together, lol, a Circuit, lol x2!, so we can start ordering the needed items to enable us to make this miracle happen ?!!? But to make it idiot-proof (dumb-it-right-down for us!) and extremely simple circuit diagram, not the actual way you geniuses write em, if say to draw a semiconductor, i would draw a square then draw 3 lines coming out the bottom of it to show the legs of it! We were only-just able to follow the circuit diagram HERE - ONLY BECAUSE there was a picture of exactly how the circuit looked, in-real-life! So we followed the wires exactly to make the solder fume extractor but were only able to, again, because of the pics! please help! i feel like crying! lol ! We have both spent a few years trying to read electrical diagrams and we get lost very easily ! Is there even a way to dumb it down for us ??? Is there any hope ?!!?  lol A very-Many thanks in advance to all for reading this and even more for any help received !!!!

Topic by offtherails2010    |  last reply

Magnets, Magnetism, Field lines ???? An expert is needed for green wind power.

This is best placed in the green group as it is for the production of green electricity, but I think that it would not be out of place in the science section also. I have an idea, quite probably not an original one but an idea all the same. It came about as we go camping as a family and have been off the grid a few times. Basically we have had no way of charging our electronic devices for longish periods. Solar power I hear you cry, well that is all well and good if you live in a country that has good sunlight, but here in the UK it can be unpredictable and not produce enough charge to power modern devices. I am mucking about with dynamo’s on the bikes (pedal ones) and wind up devices. Something I am looking into is things like wind power or improved dynamo power. The basic principal behind all of these forms of power production is that of passing a conductor through a magnetic field to produce a potential difference on that conductor. Simples (reference to meerkat advert It has been a very long time since I have done anything like this (way back in school all those years ago) so please stick with me on this one. If I remember right the principal theory is that 1. The higher number of conductors (or loops in the coil) that passes through the field lines causes the voltage to be higher. 2. The stronger the magnetic flux the higher the current production within the conductors. This is a bit basic to some of you I am sure but I still need to get it out to confirm my thoughts. If this is wrong please correct me, as the title says, an expert is needed lol The bar magnet field lines project from the N end and loop back to the S end in this fashion Image 1 Putting two bar magnets together with N and S facing gives a field pattern like this Image 2 Now this is where I need the most help with. Toroidal magnets produce a different field pattern, and as far as I can make out from the internet it looks like this Image 3 & 4 What I want to know is what happens when you put two toroidal magnets on top of each other, what happens to the field lines then. I have thought that there are a few possibilities on this, the first is that the circular lines will extend to encompass both magnets creating like an hour glass formation in the cross section. The second is that field lines will combine/intermingle between the magnets and create a figure 8 pattern. In either of the two possibilities the field strength will be increased to what could be considered a focal point between the two magnets. So with the technical thoughts out of the way and progressing on the assumption that I am correct so far my thought of a high powered dynamo is this. A central shaft that is spun by wind or other means, attached to this shaft are disks like platters on a hard drive, attached to those platters are the toroidal magnets. The magnets are aligned and spaced to give maximum condensing of the field lines between the upper and lower platter. In the centre of the two (or more) platters is a fixed platter, not attached to the shaft and is stationary. On this stationary platter are the coils, fixed into position. Image 5 The coils are shaped and could be something like the voice coils out of a hard drive, which would be good as they would determine the size of the platters, being key stone shaped they will fit together to make a ring of coils. Image 6 The whole idea is based upon the maximising and focusing of the field lines from the magnets to a point producing the maximum amount of energy as the coils pass through the lines. I also think that due to the shaft being turned having little resistance or weight that even small amounts of wind energy would be able to turn it to produce the desired outcome. Now this is where I ask you all to comment and take my thoughts to bits where I have assumed things that are wrong. I have no problems being told where I am wrong as long as it is not in a nasty way. Cheers all

Topic by Batdragon  

how to convert a mortor in toy car into a dynamo & how to make a easy solar cell which can charge six volts battery ?

What should be done to make a dynamo . where can i get the parts required, suggest me necessary parts to make a solar cell and solar panal easily

Question by vamsi srinivas    |  last reply

"Contactless Dynamo" / Wind generator showing weird multimeter readings? Answered

I am trying to replicate this, more or less, It's a setup using hard drive magnets and the coil from a relay to generate electricity.  My problem is that every configuration I have tried gives me weird negative and positive numbers(around -20  to 20, constantly changing while the magnets are spinning), and only in the hundredths of volts setting(on the multimeter, the volt, and thousands of a volt settings show nothing).  I have tried using: hdd magnets and round magnets (8 of them in a N-S-N configuration);  a relay coil, a small transformer coil, and winding my own coils 3 times.  The hand-wound coils have approx. 159 turns, 200 turn, and 250 turns, all with thin very thin enamel-coated wire, as it's my understanding that thinner wire will output more voltage.  No matter what configuration, I get the same erratic readings.  What am I doing incorrectly?

Question by chrispaccord    |  last reply

LED powered by ENERGY HARVESTING and nano-dynamo generator. possible ?

I have seen a dance floor which lights up LEDs powered by footsteps.  What is the generator that powers the LEDs?  I want to make an art project that places an generator in a tree and harvests the kinetic energy to power LEDs at night.  To take place at a music festival in 2011. Is there a system that I can build or parts that I can buy? Would love the help as the idea is burning away in my head and i need to get started. Thanks Will

Question by Will i was    |  last reply

I want to generate energy with a motor.The size have importance or only the voltage matters?

I am building a project to generate eletricity with a motor. I want to know if the motor size(lenght, diameter, etc.) have inportance on the generated power or only the motor voltage matters? My motor: - 3,5cm diameter - 6,0cm lenght - 9,0v power Sorry the poor english... Thanks the help!

Question by XPProductions  


This is not a scan of the original book, but the original book converted to text with OCR, and strictly proof read with QC controls. Thus the charts, formulas can be copied and pasted into something else.   ELECTRICITY FOR THE FARM LIGHT, HEAT AND POWER BY INEXPENSIVE METHODS FROM THE WATER WHEEL OR FARM ENGINE BY FREDERICK IRVING ANDERSON AUTHOR OF "THE FARMER OF TO-MORROW," ETC., ETC. New York THE MACMILLAN COMPANY 1915   PREFACE This book is designed primarily to give the farmer a practical working knowledge of electricity for use a slight, heat, and power on the farm. The electric generator, the dynamo, is explained in detail; and there are chapters on electric transmission and house-wiring, by which the farm mechanic is enabled to install his own plant without the aid and expense of an expert.    With modern appliances, within the means of the average farmer, the generation of electricity, with its unique   conveniences,   becomes   automatic,   provided   some   dependable   source   of   power   is   to   be had—such as a water wheel, gasoline (or other form of internal combustion) engine, or the ordinary windmill. The water wheel is the ideal prime mover for the dynamo in isolated plants. Since water-power is running to waste on tens of   thousands of our   farms throughout   the country,   several chapters are devoted to this phase of the subject: these include descriptions and working diagrams of weirs and other simple devices for measuring the flow of streams; there are tables and formulas by which any one, with a knowledge of simple arithmetic, may determine the power to be had from falling water under given conditions; and in addition, there are diagrams showing in general the method of construction of dams, bulkheads,   races, flumes, etc.,   from materials usually to be found on a farm. The tiny unconsidered brook that waters the farm pasture frequently possesses power enough to supply the farmstead with clean,   cool,   safe   light   in place of   the dangerous,   inconvenient oil   lamp;   a   small   stream capable of developing from twenty-five to fifty horsepower will supply a farmer (at practically no expense beyond the original cost of installation) not only with light, but with power for even the heavier farm operations, as threshing; and in addition will do the washing, ironing, and cooking, and at the same time keep the house warm in the coldest weather. Less than one horsepower of energy will light the farmstead; less than five horsepower of energy will provide light and small power, and take the drudgery out of the kitchen.   For those not fortunate enough to possess water-power which can be developed, there are chapters on the use of the farm gasoline engine and windmill,   in connection with the modern storage battery, as sources of electric current.

Topic by Lateral Thinker  

any device to convert battery to ac mains?

Is there a way to power any ac 240v device via batteries, usb or dynamo?

Question by connorfrancis    |  last reply

Can we couple a motor and generator?

Can we couple a motor and generator(or dynamo, small scale) so that we can get the battery charged again? If any means possible can we amplify the power generated from the dynamo?

Question by GouthamG4    |  last reply

Gameboy Volt / Speed ?

Hi, I am working on a little project with my olde Gameboy Color ! I am taking it out of its case, and building a wooden / bronze one in SteamPunk Style. Now to get even Nerdier i am considering to build a "Stirling engine" and power the little machine with a Dynamo attached to it! However this might turn out, i would like to know if the dynamo generates more than 3V if that would speed the Gameboy up, or simply fry it? I will add a Good Resistor to prevent that btw :p

Topic by Schoening    |  last reply

Hoemade bike USB Charger not charging iPhone

Hi, I made a bike phone charger using a motor as a generator connected to a linear voltage regulator. The output current is stable at 5.05V and 1.1a (measured with a multimeter). Any USB device works, except iPhone and other Apple devices. It starts charging and 2 seconds later I get “This accessory may be not supported”Anyone knows what’s happening? Thanks.

Question by AdelCraft    |  last reply

how would I go about charging a car battery with a bike without making the bike unusable for transport?

I am trying to build a non-Gas powered motorized bicycle, and I realized that it may be possible to have multiple power inputs like wind and solar feeding the charge. however, as a jobless 16 year old, I can't test my ideas. I am attempting to create a bicycle that charges while you pedal, storing energy in the car battery. then, the car battery can be used to power a motor powerful enough to keep the bike in motion. Also, yes I know that this would likely be VERY bulky, but I can come up with a solution for that. please help me if you can.

Question by psynergyhound    |  last reply

Best motor suited for a diy generator that can provide 48V?

Ok, out of all places, I've seen this particular question be asked once and the discussion trailed off topic somewhere. Before we start, Yes it's a bit of a backwards thought but it's still a project, experiment and I'd do it for the sake of doing it. I have an electric scooter - lack of knowledge for proper battery care during winter lead it to 4 dead batteries. In my area, as long as the scooter is moved by an electric motor and makes less than 40km/h it's a street legal and non insurance or license requiring vehicle. Only issue for me is the limit of the battery capacitance and the eventual depreciation of the battery capacity. So I want to try an experiment of strapping a small weedwacker motor or even a hobby airplane fuel motor to an electric motor to act as a power source for the scooter. Don't laugh, It's an experiment. Yes, I'm aware I can just buy batteries. they are 50 bucks a battery + 12 bucks shipping and mine ran on 4x of these suckers. Buying batteries would work but would not satisfy the curiosity of an experiment.. Now then: ============================================== My scooter, when bought, could do about 12 blocks (1 block = 2km ) trip on a full charge. Before this winter, it could do 8 barely. It ran on 4x Lead Acid 12v 18Ah batteries. Now the batteries are connected in series so that's 4x 12v 18Ah making it 48v 18Ah. At this point we can drop the need to have the generator produce exactly 18Ah of current because that originally is the total battery capacitance, determining how long we can ride before draining of the batteries. So with a generator, all we need is to draw sufficient Current at the moment of generation. Which motors are best suited for generating 48v. I'm obviously missing some que variables here but I just want a point in the right direction. I'll most likely need extra head room and make a Step Down Buck Converter. Every time A talk of a diy generator comes up, people seem to mention Stepper motors. Seem like good choices? Brush-less, multi lead motors, yes - no?

Question by MilesT9    |  last reply

i have made 4 bicycle dynamos each gives -2-3 volts .i need a way to combine all this so i can get 1 single big power !?

I have made 4 bicycle dynamos each made using a normal dc motor and each  produce 3 volts .i want to know how should i connect  them so that their powers suplies produced can be combined and which can give me 1 big single supply ?

Question by roboguy22    |  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