As a generator on the windmill, a stepper motor (SD) for the printer is suitable. Even with a small speed of rotation, it produces a power of about 3 W. The voltage can rise above 12 V, which makes it possible to charge a small battery.
Principles of use
The turbulence of the wind characteristic of the Russian climate in the surface layers leads to constant changes in its direction and intensity. Large-sized wind generators, the power of which exceeds 1 kW will be inertial. As a result, they will not have time to fully spin when the wind direction is changed. This also interferes with the moment of inertia in the rotation plane. When the side wind acts on a working windmill, it is experiencing huge loads that can lead to its rapid failure.
It is advisable to apply a low-power wind generator, made with your own hands, having minor inertia. With their help, you can charge low-power batteries of mobile phones or use to illuminate cottages by LEDs.
In the future, it is better to focus on consumers, inappreating transformations of the generated energy, for example, to heal water. Multi-dozen watts of energy may well be enough to maintain temperature hot water Or for additional heating of the heating system so that it does not move in winter.
Electrical part
The generator in the windmill can be installed a stepper motor (shd) for the printer.
Even with a small speed of rotation, it produces a power of about 3 W. The voltage can rise above 12 V, which makes it possible to charge a small battery. The remaining generators work effectively at the speed of rotation more than 1000 rpm, but they will not fit, because the windmill rotates at a speed of 200-300 rpm. Here we need a gearbox, but it creates additional resistance and also has a high cost.
In the generator mode, a stepper motor produces an alternating current that is easy to convert to constant using a pair of diode bridges and condensers. The scheme is easy to assemble with your own hands.
By installing the stabilizer by the bridges, we obtain a constant output voltage. For visual control, you can still connect the LED. To reduce voltage loss to straighten it, Schottky diodes are used.
In the future, you can create a windmill with more powerful shd. Such a wind generator will have a big moment touch. The problem can be eliminated by shutting down the load during start-up and with small revolutions.
How to make a wind generator
The blades can be made with your own hands from PVC pipe. The desired curvature is selected if you take it with a certain diameter. The blank of the blade is drawn on the pipe, and then cut out the cutting disk. The scope of the screw is about 50 cm, and the width of the blades is 10 cm. After it is necessary to pull the sleeve with the flange under the size of the shaft shd.
It is satisfied with the engine shaft and is attached additionally with screws, and plastic blades are attached to the flanges. The photo shows two blades, but you can make four, screwing two more similar at an angle of 90º. For greater stiffness under the screw head, you should install a common plate. It will fit the blade to the flange.
Plastic products do not serve for a long time. Long wind at a speed of more than 20 m / s such blades will not stand.
The generator is inserted into a piece of the pipe to which it is attached by bolts.
The tube is fastened to the tube from the end, which is an openwork and lightweight design of duralumin. The wind generator holds on a welded vertical axis, which is inserted into the mast pipe with the possibility of rotation. Under the flange, you can install a thrust bearing or polymer washers that reduce friction.
Most of the windmill designs contain a rectifier that is attached to the moving part. This is inappropriate due to an increase in inertia. The electrical board can be placed at the bottom, and to display down the wires from the generator. Usually from a stepper motor exits up to 6 wires corresponding to two coils. For them, there are current collecting rings for transmitting electricity from the movable part. They are quite difficult to install brushes. The mechanism of the current conversation may be more complicated than the wind generator itself. It would also be better to place the windmill so that the generator shaft is vertically. Then the wires will not be thrown around the mast. Such wind generators are more difficult, but inertia decreases. The conical transfer here will be just right. At the same time, the generator shaft turnover can be increased, choosing the necessary gears with their own hands.
Securing the windmill at an altitude of 5-8 m, you can start testing and collecting data on its capabilities in order to further establish a more advanced design.
Currently, vertically axial wind generators are becoming popular.
Some structures are well withstanding even hurricanes. Combined structures operating at any wind have proven well well.
Conclusion
The low-power wind generator works reliably due to small inertia. It is easily manufactured at home and used mainly to recharge small batteries. It can come in handy in a country house, in the country, in the campaign, when problems with electricity arise.
Driving on a bike past dacha sites, I saw a working wind generator:
Large blades slowly, but rightly rotated, the fluger oriented the device in the direction of the wind.
I wanted to realize a similar design, albeit not able to produce power sufficient to ensure "serious" consumers, but still working and, for example, charging batteries or feeding LEDs.
Stepper engines
One of the most effective options for a small homemade wind power generator is to use stepper Engine (Shd) (eng. stepping (STEPPER, STEP) Motor) - In such a motor, the shaft rotation consists of small steps. The stepping motor windings are combined into phases. When the current is supplied to one of the phases, the shaft moves one step.
These engines are low-speedand the generator with such an engine can be without a gearbox connected to a wind turbine, a stirling engine or another low-speed power source. When used as an ordinary (collector) engine generator direct current To achieve the same results, it would be required 10-15 times a higher rotational speed.
A feature of the header is a fairly high moment of start (even without electrical load connected to the generator), reaching 40 grams of force on a centimeter.
The efficiency coefficient of the generator from the SD reaches 40%.
To check the performance of the stepper motor, you can connect, for example, a red LED. Rotating motor shaft, you can observe the glow of the LED. The polarity of the connection of the LED does not matter, since the engine produces an alternating current.
There are enough stores powerful engines Fixed flexible disc drives, as well as old printers and scanners.
Engine 1.
For example, I have a shd from the old 5.25 "drive worked as part ZX Spectrum - compatible computer "byte".
Such a drive contains two windings, from the ends and the middle of which conclusions are made - the engine is derived from the engine six Wires: 
First winding (eng. cOIL 1.) - blue (eng. blue) And yellow (eng. yellow);
Second winding (eng. cOIL 2.) - Red (eng. red) And white (eng. white);
brown (eng. brown.) Wires - Conclusions from midpoints of each winding (eng. center Taps.).
disassembled stepping motor
The engine is visible to the left, on which the "striped" magnetic poles are visible - North and South. It is clearly visible a stator winding, consisting of eight coils.
Half resistance of the winding is ~ 70 ohms.
I used this engine in the original design of my wind generator.
Engine 2.
At my disposal less powerful stepper engine T1319635. Firms Epoch Electronics Corp. From scanner HP Scanjet 2400. It has five Conclusions (Unipolar Motor): 
First winding (eng. cOIL 1.) - Orange (eng. orange.) And black (eng. black.);
Second winding (eng. cOIL 2.) - brown (eng. brown.) And yellow (eng. yellow);
red (eng. red) Wire - connected together conclusions from the midpoint of each winding (eng. center Taps.).
Half resistance winding is 58 ohms, which is indicated on the engine housing.
Engine 3.
In the improved version of the wind generator, I used a stepping motor Robotron SPA 42 / 100-558produced in the GDR and the voltage designed for 12 V: 
Wind turbine
There are two options for the arrangement of the axis of the impeller (turbine) of the wind generator - horizontal and vertical.
Advantage horizontal(most popular) Location The axes located in the direction of the wind is more efficient use of wind energy, disadvantage - complication of the design.
I chose vertical location axis - Vawt. (vertical Axis Wind Turbine), which significantly simplifies the design and does not require orientation in the wind . This option is more suitable for mounting on the roof, it is much more efficient in the conditions of fast and frequent changes in the direction of the wind.
I used the type of wind turbine, called the Savonius wind turbine (eng. Savonius Wind Turbine.). It was invented in 1922 Sigurd Johannes Savonius (Sigurd Johannes Savonius) From Finland. 
Sigurd Johannes Savonius
The work of the Savonius wind turbine is based on the fact that resistance (eng. drag.) The airflow of the air - the wind of the concave surface of the cylinder (blades) is greater than the convex.
Aerodynamic resistance coefficients (english drag Coefficients) $ C_D $
Two-dimensional bodies:
concave half of the cylinder (1) - 2.30
Convex half of the cylinder (2) - 1.20
Flat Square Plate - 1.17
three-dimensional bodies:
concave half hemisphere (3) - 1.42
Convex half hemisphere (4) - 0.38
Sphere - 0.5
The specified values \u200b\u200bare given for Reynolds numbers (English. Reynolds Numbers) In the range of $ 10 ^ 4 - 10 ^ 6 $. The Reynolds number characterizes the behavior of the body in the medium.
Body Resistance Power Air Flow $ (F_D) \u003d ((1 \\ OVER 2) (C_D) S \\ RHO (V ^ 2)) $, where $ \\ rho $ - air density, $ V $ - Airflow speed, $ s $ - body cross section.
Such a wind turbine rotates in the same side, regardless of the direction of the wind: 
A similar principle of operation is used in a cup anemometer (eng. cup Anemometer) - Device for measuring wind speed: 
Such an anemometer was invented in 1846 by Irish Astronomer John Thomas Romney Robinson ( John Thomas Romney Robinson):
Robinson believed that the cups in its four-stage anemometer were moved at a speed equal to one third of the wind speed. In reality, this value varies from two to a little more than three.
Currently, three-dimensional anemometers developed by Canadian meteorologist John Patterson ( John Patterson.) In 1926: 
Generators on DC collector engines with vertical microturbine are sold on eBay. For price about $ 5: 
Such turbine contains four blades located along two perpendicular axes, with a diameter of a 100 mm impeller, a height of a blade of 60 mm, a length of chord 30 mm and a 11 mm segment height. The impeller is attached to the DC collector micromotor shaft with marking JQ24-125H670.. The nominal supply voltage of such an engine is 3 ... 12 V.
The energy produced by such a generator is enough for the luminescence of the "White" LED.
Savonius wind turbine rotation speed can not exceed wind speed , but this design is characterized high torque (eng. torque).
The efficiency of the wind turbine can be estimated by comparing the power generated by the wind generator with a power concluded in the wind blowing the turbine:
$ P \u003d (1 \\ Over 2) \\ Rho S (V ^ 3) $, where $ \\ rho $ is air density (about 1.225 kg / m 3 at sea level), $ s $ - oven turbine area (eng. sWEPT Area), $ V $ - wind speed.
My wind turbine
Option 1
Initially, four blades are used in the impeller of my generator in the form of segments (halves) of cylinders cut from plastic pipes:
Size segments -
segment length - 14 cm;
segment height - 2 cm;
The length of the chord segment is 4 cm;
I installed the collected design on a high enough (6 m 70 cm) of a wooden mast from a bar attached by self-drawing to a metal frame: 
Option 2.
The lack of a generator was quite high wind speed required for the promotion of the blades. To increase the surface area, I used blades cut from plastic bottles:
Size segments -
segment length - 18 cm;
segment height - 5 cm;
The length of the chord segment is 7 cm;
The distance from the start of the segment to the center of the axis of rotation is 3 cm.
Option 3.
The problem was the strength of the blades holders. At first I used perforated aluminum planks from the Soviet children's designer 1 mm thick. After a few days of operation, the strong gusts of the wind led to a breakdown of slats (1). After this failure, I decided to cut the holders of the blades from the foil textolite (2) with a thickness of 1.8 mm: 
The strength of the textolite for bending is perpendicular to the plate is 204 MPa and comparable with aluminum bending strength - 275 MPa. But the aluminum elastic module $ E $ (70,000 MPa) is much larger than that of the textolite (10,000 MPa), i.e. Texolit is much more elastic aluminum. This, in my opinion, taking into account the greater thickness of the textolite holders, will ensure much greater reliability of the fastening of the wind-generator blades.
The wind generator is mounted on the mast: 
Experienced operation of the new version of the wind generator showed its reliability even with severe wind gusts.
The disadvantage of the Savonius turbine is low efficiency
- Only about 15% of wind energy is converted to the energy of the shaft rotation (it is much less than it can be achieved with darier wind turbine (eng. Darrieus Wind Turbine.)), using lifting force (eng. lift.). This type of wind turbine was invented by the French aircraft designer George Daria (Georges Jean Marie Darrieus) -uS Patent from 1931 No. 1,835,018 .
Georges Darier
The disadvantage of the turbine Daria is that she has a very bad self-timing (to generate a torque from wind turbine should already be promoted).
Electricity transformation generated by a stepper engine
The conclusions of the stepping motor can be connected to two bridge rectifiers collected from Schottky diodes to reduce the voltage drop on diodes.
You can apply popular Schottky diodes 1N5817. with maximum reverse voltage of 20 V, 1N5819. - 40 V and maximum direct medium straightened current 1 A. I connected rectifier outputs consistently in order to increase the output voltage.
You can also use two rectifiers with a midwater. Such a rectifier requires two times less diodes, but the output voltage decreases twice.
The pulsating voltage is then smoothed using a capacitive filter - a condenser 1000 μF by 25 V. to protect against increased generated voltage parallel to the condenser included Stabilion on 25 V. 
scheme of my wind generator
electronic block of my wind generator
Application of the wind generator
The voltage generated by the wind generator depends on the size and constancy of the wind speed.
With wind, pelling thin branches of trees, the voltage reaches 2 ... 3 V.
In the wind, the pelling thick branches of trees, the voltage reaches 4 ... 5 V (with strong gusts - up to 7 V).
Connection to Joule Thief
The smoothed voltage from the wind generator capacitor can be supplied to - low-voltage DC-DC converter 
Resistor resistance value R. It is selected experimentally (depending on the type of transistor) - it is advisable to use a variable resistor by 4.7 kΩ and gradually reduce its resistance, achieving stable work converter.
I collected such a converter on the basis of Germany pNP.-Transistor GT308V ( Vt.) and a pulsed transformer MIT-4B (coil L1 - conclusions 2-3, L2. - Conclusions 5-6): 
Charge of ionistors (supercapacitors)
Ionistor (supercapacitor, eng. supercapacitor) is a hybrid capacitor and chemical source Current.
Jonistor - unpolary The element, but one of the conclusions can be marked with an "arrow" - to designate the polarity of residual voltage after it is charging at the factory.
For initial research, I used an ionistor With a capacity of 0.22 ° C voltage 5.5 V (diameter 11.5 mm, height 3.5 mm):
I connected it through a diode to the output via germanium diode D310.
To limit the maximum voltage of the charging of the ionistor, you can use a stabilion or a chain of LEDs - I use a chain from two Red LEDs: 
To prevent the discharge of the already charged ionistor through restrictive LEDs HL1 and HL2. I added another diode - VD2..
To be continued
Usually blowing a light breeze, but my mini windmill is periodically spinning to very large revolutions, the screw rotates at such a speed that it is practically not visible, though, with such revolutions, the bastings rocate can be rocked. Syuh, this windmill supported in working condition an old, but the working battery so that it does not discharge. The maximum power of the windmill is only up to 100m, it may be possible to give out and more, but we usually blow with a small wind, and frozen on the usual breeze.The design of such windmills spied on the same overseas site and decided to repeat, and this baby was born. As a generator, a stepper motor from a long time of non-working and drifting in my inkjet printer was used. Obraveling him twisted the fiberglass. Further I looked, turned it, twisted with my hands, I remembered how much it gives, I gave very little, but the volts rose above 12, which means he couldoretically charge the battery.
Next, from the transistor made a mount for the blades. The transistor drilled on the diameter of the shaft on which the gear nozzle was becoming, in general under its size. She put on the tree of the transistor, drowned glue and twisted making sure that everything is smooth. Then finally fixed with the help of epoxy. Divorced a little and flooded the hole of the transistor, additionally defended the motor from the bad weather shrouding holes in the motor. Below is the photo of this generator.
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Next, from the segment of PVC pipes, with a diameter of 110mm, cut the blade, the billet was drawn on the pipe, which cut out the cutting machine. The sizes took the exemplary width turned out to be 9cm, and the scope of the screw is 48cm. Drilled holes and screwed the screw to the motor-generator with the help of small bolts.
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The base used a segment of a 55-to-one PVC pipe, then cut the tail from the plywood, and added a piece from 110-to.torchik. Increased pipes. After the assembly, it turned out such a wind power station. Immediately gathered a rectifier. So, as this motor did not want to give a lot of volts on small revolutions, I collected according to the doubling scheme and turned on sequentially.
Diodes took HER307, capacitors - 3300mKF
The scheme looked into polyethylene and put the rectifier into the pipe, then the engine and tied it with a wire through the drilled dyskochki, the space was smeared with silicone. So, Silicone then stalked all the holes on top, and the bottom drilled one hole just in case, so that if the water is glass, and the condensate evaporated.
The tail secured through the bolt, the semicircular tail inserted and tied with a wire, he was so firmly held. Found the center of gravity, drilled (dia. 9mm.) I still drilled dia. 6mm Two bolts M10, through, under the axis. (M10 bolts here serve as the "axis bearing) screwed from above and below the M10 bolts into the pipe, smeared the long bolt M6 solidol and twisted everything, it turned out quite rustling. The bolt-axis (M6) screwed to the corner, and its stick. From above on the M10 bolt dressed on Silicone cork, now the axis of the water is not afraid. All wind generator is made.
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For the mast took several storces. who twisted self-drawing, secured the windmill and raised to the Werker. Connected to the battery, charging comes, but very weak, supports the battery from a natural discharge. Since the yard is spinning, I was satisfied, at least I would know where the wind blows. This option is - as it is said on that site - Little Weekend Project, then-there is a small project for the weekend, for the pleasure of a thread to pick up, the more I am not I spent a penny ... glue is not counting. So, in theory, a couple of small LEDs will be lit, or a mobile phone in a couple of days to charge, but most likely such a weak current will take the phone for bad contact and turn off by writing a bad connection on the display.
In the future, if there is a time and desire, I can make on the courtyard lighting, that's just the second one and the small battery will put a small battery, or several batteries. For this, one more stepper remained, only this gives a 2x20 volt from scrolling with hand, but the current is small. And the second - on the brushes, immediately stand. From hand 10 volts, KZ - 0.5 amp. And I will still torment the autogenerator, just the magnets wait.
The power supply of country houses, country houses or cottage settlements is often distinguished by instability. The lines are worn, interruptions from accidents or cliffs of wires occur much more often than wanted. There is no time to correct damage, but also small intervals create a lot of inconvenience. The solution to the issue can be the installation capable of providing the main consuming instruments.
Mini wind generator do it yourself
The dimensions of the wind generator should not necessarily affect the imagination by its grandeur. The current is capable of producing a current and a small installation created from small girlfriends or devices. It can be a textbook for children, source of lighting for emergencies, battery charger mobile phone etc.
Costs are reduced in tens of times, efficiency is obtained by such what was laid when creating a project. As a trial model that allows you to work out technology and get some experience in creating such devices, a mini-wind generator can be. For the manufacture, you can use various from the failed or outdated equipment.
Use old computer cooler
For windmaster manufacturing need a big cooler, he gives out top scores And convenient in work. First of all, it is necessary to disassemble it. The sticker is removed, the plug and locking ring is removed. After that, the cooler is easily disassembled along the axis of rotation into two approximately the same than half the sizes.
One of them is a rotor, whose blades will have to change to larger ones. For this, old blades are neatly clouted or cut off, new, about 4 more than the previous ones are made from the plastic bottle. It is convenient to take three things, they will have a sufficient base area for durable gluing.
There are four windings on the stator. They can be left in inviolability, or change the number of turns. It takes a thinner wire and wounds on everything in turn, and, in different directions. Coils are connected accordingly.
After that, it is necessary to make a rectifier, for which four diode will need. They are connected in pairs sequentially, then parallel. The wires are joined, the device is ready. To install it on the wind, you will need a stand or a small mast, which is easiest to make from trimming a metal tube. In order for the windmill independently put on the wind, you will need a tail stabilizer, like an aircraft tail.
A tester or LED flashlight is joined to verify performance.
Akb charging device
A small wind generator capable of charging car battery - Extremely practical and necessary device. It is necessary to ensure a voltage not exceeding the Nominal Akb (usually 12 V), otherwise the risk of reloading and boiling the battery will appear.
As a generator will need homemade device appropriate power or ready asynchronous engine, Tractor or automotive generatorcapable of creating a charge voltage. To protect against recharge, you will need a controller based on a car regulator, disconnecting charge when too high voltage appears.
Matching winder
Have matching windmillallowing you to get the maximum comfort from being in nature, convenient and useful for each travel lover. The requirements for such a windmill are obvious:
- compactity
- the ability to quickly build or disassembly for transportation
- power providing electricity required devices
It will be needed to make an impeller with disconnecting blades and a generator issuing sufficient power. Optimal option - horizontal type, with blades on the screws. The generator is best to adapt from the car, it needs a little upgrades (rewind of coils) and the installation of magnets on the rotor (neodymium magnets are used to excite windings).
In nature, it is enough to consolidate the device on the trunk of a tree or a different suitable support and put it on the wind. For compactness, you can not make the rotation device around the vertical axis and adjust the position manually.
Windmill from a stepper motor from the printer
Stepper engines are capable of issuing 12 and more volt, but they are small with them. The design does not allow to strengthen their windings, so used as it is. The appropriate size blades are installed on the shaft made from polypropylene sewer pipes. It will be necessary to assemble the simplest rectifier. Ordinary stepper engines in theory are able to charge a mobile phone battery in a couple of days, but in practice it is very difficult to use it possible to highlight with LED flashlights.
Other possible options
For production of a mini-wind generator You can use any electric motors from household appliances. You can accommodate the engine from the ribbon mechanism, from the old microwave (fan), different variants Brush structures. They all have small power And they will not be able to provide any serious devices, but as trial models created with children and giving experience and understanding of the process, all these options are quite suitable.
On the basis of the knowledge gained and the skill, a more productive wind generator can be created, capable of providing the needs of a private house, to translate it to the offline power supply mode.
It came to mind simple, obvious, but ingenious thought. After all, if you consider that the stepper motor is not only a motor that provides mechanical work absolutely different devices (From the printers of scanners and other office equipment, ending with various units applied in more serious devices). The stepping motor can also serve as an excellent electricity generator!
And his most important plus in everything is that it is not at all necessary for big turnover, it may well work fine at low loads. That is, even with a minimal action of the force directed to it, the stepper engine perfectly produces energy. The most important thing is that this energy is quite enough for various needs, such as lighting the road by a biker using a lantern connected to a stepping motor.
Unfortunately with the usual generator, the standard bike is still needed initial speed, before the flashlight starts to emit rays enough bright light for clear lighting of the path. But when using a stepper motor, this lack is removed by itself, that is, the lighting will be supplied immediately as soon as the wheel is rotated.
But the truth of this miracle design will still have a number of shortcomings. For example, the most clear of them is a great magnetic sticking. But in fact it is not so scary for the cyclist.
What starting work, we will need to find some details:
1) Actually the stepping motor itself.
2) large capacitance paternal capacitors.
3) LED lights
4) Voltage stabilizer 5-6 volts.
Find a stepper engine is quite simple due to the fact that it is very common in all office devices. The only thing you need to understand is that the larger the stepper engine, respectively, it is better for us.
It will also describe and present several models of stepper motors and various options for their mounting to the iron horse.
To start, take the most large Enginethat managed to get the author. He dismantled him from an ordinary office plotter for printing (in fact, this is a printer, only several times more).
Externally, the engine is quite large.
But before proceeding to the study of the stabilization scheme as well as the power scheme, it is worth paying attention to the method of fastening this unit to cycle.
If you look at the drawing, you will understand that the generator is located closer to the axis of the wheel and the rotation is transmitted from the additional circle.
And yet, since the bicycle model has each other and someone does not want to damage the frame with self-drawing, you will need to develop the fastening itself as well as a circle of rotation, the options here really a lot.
If you do not imagine how to fasten a large stepping engine to the design, there is a smaller option:
You can only choose the option of the generator suitable for the sizes of your vehicle.
Well when with stepper engines figured out, you can proceed to lanterns and nutrition chains.
Lanterns need to take LED. The straightening scheme will look like this: a block of rectifier diodes, several large capacitance capacitors and a natural voltage stabilizer. In principle, this is a standard power scheme.
The stepper motor standard has four wiring on the output, which correspond to two coils. It is for this reason that the rectifier block is also two. This homemade generator Electricity may well produce up to 50 volts voltage on large revs, so that the capacitors are better to take appropriate (voltage above 50). Well, the stabilizer to voltage is 5-6 volts.
And so what is the essence of homemade, and why did she need it?
It's all about its advantage, even just touching the way, the path will be brightly lit by the lantern, driven from our stepper engine, and he is the generator.
I would also like to note that in the process of movement, the flashlight will not flash or flash- lighting will be smooth and smooth.
