A stepper motor (SM) for a printer is suitable as a generator for a windmill. Even at a low rotation speed, it produces about 3 watts of power. The voltage can rise above 12 V, which makes it possible to charge a small battery.

Principles of use

Wind turbulence in the surface layers, characteristic of the Russian climate, leads to constant changes in its direction and intensity. Wind generators large sizes, the power of which exceeds 1 kW will be inertial. As a result, they will not have time to fully unwind when the wind direction changes. This is also hampered by the moment of inertia in the plane of rotation. When a side wind acts on an operating wind turbine, it experiences enormous loads, which can lead to its rapid failure.

It is advisable to use a low-power wind generator, made by yourself, which has insignificant inertia. With their help, you can charge low-power mobile phone batteries or use them to illuminate your dacha with LEDs.

In the future, it is better to focus on consumers that do not require conversion of the generated energy, for example, for heating water. A few tens of 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 freeze in winter.

Electrical part

As a generator, you can install a stepper motor (SM) for a printer in a windmill.

Even at a low rotation speed, it produces about 3 watts of power. The voltage can rise above 12 V, which makes it possible to charge a small battery. Other generators operate effectively at a rotation speed of more than 1000 rpm, but they will not be suitable since the windmill rotates at a speed of 200-300 rpm. A gearbox is needed here, but it creates additional resistance and also has a high cost.

In generator mode stepper motor is being produced alternating current, which can be easily converted to DC using a pair of diode bridges and capacitors. The circuit is easy to assemble with your own hands.

By installing a stabilizer behind the bridges, we get a constant output voltage. For visual control, you can also connect an LED. To reduce voltage loss, Schottky diodes are used to rectify it.

In the future, it will be possible to create a wind turbine with a more powerful motor. Such a wind generator will have a high starting torque. The problem can be eliminated by disconnecting the load during startup and at low speeds.

How to make a wind generator

You can make the blades yourself from PVC pipe. The required curvature is selected if you take it with a certain diameter. The blade blank is drawn on the pipe and then cut out with a cutting disc. The propeller span is about 50 cm, and the width of the blades is 10 cm. Then you should grind the sleeve with a flange to the size of the motor shaft.

It is mounted on the motor shaft and additionally secured with screws, and plastic blades are attached to the flanges. The photo shows two blades, but you can make four by screwing two more similar ones at an angle of 90º. For greater rigidity, a common plate should be installed under the screw heads. It will press the blades closer to the flange.

Plastic products do not last long. Such blades will not withstand prolonged wind with a speed of more than 20 m/s.

The generator is inserted into a piece of pipe to which it is bolted.

A weather vane is attached to the end of the pipe, which is an openwork and lightweight structure made of duralumin. The wind generator is supported on a welded vertical axis, which is inserted into the mast pipe with the possibility of rotation. A thrust bearing or polymer washers can be installed under the flange to reduce friction.

For most designs, the windmill contains a rectifier, which is attached to the moving part. This is impractical to do due to the increase in inertia. The electrical board can be placed at the bottom, and the wires from the generator can be brought down to it. Typically there are up to 6 wires coming out of a stepper motor, corresponding to two coils. They require slip rings to transfer electricity from the moving part. It is quite difficult to install brushes on them. The current collection mechanism may be more complex than the wind generator itself. It would also be better to place the windmill so that the generator shaft is vertical. Then the wires will not be tangled around the mast. Such wind generators are more complex, but their inertia is reduced. A bevel gear will be just right here. In this case, you can increase the speed of the generator shaft by selecting the necessary gears with your own hands.

Having secured the windmill at a height of 5-8 m, you can begin to conduct tests and collect data on its capabilities in order to install a more advanced design in the future.

Currently, vertical-axis wind generators are becoming popular.

Some structures even withstand hurricanes well. Combined structures that work in any wind have proven themselves well.

Conclusion

The low-power wind generator operates reliably due to its low inertia. It is easily made at home and is used mainly for recharging small batteries. It can be useful in a country house, in the country, or on a hike when problems with electricity arise.

Creation of a wind generator does not necessarily mean the manufacture of a large and powerful complex capable of providing electricity to an entire house or group of consumers. It is possible to make one, which is, in fact, a working model of a serious installation. The purpose of such an event could be:

• Introduction to the basics of wind energy.
• Joint learning activities with children.
• An experimental sample prior to the construction of a large installation.

Creating such a windmill will not require the use of a large number of materials or tools; you can make do with improvised means. You can’t count on generating significant amounts of energy, but it may be enough to power a small LED lamp. The main problem that exists during creation is the generator. It is difficult to create it yourself, since the dimensions of the device are small. The easiest one to use is , which allows you to use it in generator mode.

Homemade windmill based on a stepper motor

Most often, when production of low-power wind generators stepper motors are used. The peculiarity of their design is the presence of several windings. Typically, depending on the size and purpose, motors are made with 2, 4 or 8 windings (phases). When voltage is applied to them in turn, the shaft rotates accordingly at a certain angle (step).

The advantage of stepper motors is their ability to produce sufficiently high current at low rotation speeds. You can install an impeller on a generator from a stepper motor without any intermediate devices - gears, gearboxes, etc. Electricity will be generated with the same efficiency as on devices of other designs using overdrive gears.

The difference in speeds is quite significant - to obtain the same result, for example, commutator motor, a rotation speed of 10 or 15 times greater will be required.

It is believed that using a generator from a stepper motor it is possible to charge batteries or batteries of mobile phones, but in practice, positive results are extremely rare. Basically, power sources for small lamps are obtained.

The disadvantages of stepper motors include the significant force required to start rotation. This circumstance reduces the sensitivity of the entire system, which can be somewhat corrected by increasing the area and span of the blades.

You can find such motors in old floppy drives, scanners or printers. Alternatively, you can purchase new engine, if the required device is not in stock. For greater effect, you should choose more large engines, they are capable of producing a voltage large enough to be used in some way.

Wind generator made from printer parts

One of suitable options- use of a stepper motor from the printer. It can be removed from a failed old device; each printer has at least two such motors. Alternatively, you can purchase a new one that has not been used. It is capable of generating about 3 watts of power even in light winds, which are typical for most regions of Russia. The voltage that can be achieved is 12 V or more, which allows the device to be considered as a battery charger.

Stepper motor produces alternating voltage. It is necessary for the user to straighten it first. You will need to create a diode rectifier, which will require 2 diodes for each coil. You can directly connect the LED to the coil terminals; if the rotation speed is sufficient, this will be enough.

The easiest way to install the rotor impeller is directly on the motor shaft. To do this, it is necessary to make a central part that can fit tightly onto the shaft. To strengthen the fixation of the impeller, it is necessary to drill a hole and cut a thread in it. Subsequently, a locking screw will be screwed into it.

For the manufacture of blades, polypropylene sewer pipes or other suitable materials are usually used. The main condition is low weight and sufficient strength, since the blades sometimes gain quite decent speed. The use of unreliable materials can create an undesirable situation where the impeller falls apart while running.

Blades

Usually 2 blades are made, but more can be made. It must be remembered that the large area of ​​the blades increases the KIEV of the windmill, but in parallel with this, the frontal load on the impeller, transmitted to the motor shaft, increases. Making small blades is also not recommended, since they will not be able to overcome the sticking of the shaft when starting rotation.

To be able to rotate the windmill around a vertical axis, you need to make a special unit. The difficulty with this lies in the need to ensure that the cable coming from the generator does not move. Since the device has, rather, a decorative purpose, they usually approach the issue in a simpler way - they install the consumer directly on the generator body, eliminating the presence of a long cable. Otherwise, you will have to install a system like a brush collector, which is irrational and time-consuming.

Mast

The assembled windmill must be installed at a height of at least 3 meters. Wind flows near the earth's surface have an unstable direction caused by turbulence. Raising it to a certain height will help get more uniform flows. For self-installation a tail stabilizer is installed in the wind along the axis of rotation, playing the role of a weather vane. It is made from any piece of plastic, aluminum plate or other available material.

I already wrote at the beginning of summer about a homemade windmill - an anemometer.

His goal was to organize the collection of wind statistics and, based on them, make a decision on the construction of a large, serious wind turbine. Unfortunately, there was neither a programmer willing to write a program for processing data from the anemometer, nor a microcontroller specialist to create the appropriate device. Therefore, alas, I had to observe the wind visually, since the weather vane was always in sight. And unfortunately, these observations are extremely depressing...

The fact is that the wind in the central zone of the European part of Russia has extreme turbulence in its surface layers. Literally within 3-5 minutes the windmill repeatedly stops (or slows down greatly) and spins up so that the blades are not visible. At the same time, the wind direction changes in the sector up to 90-120 degrees. It is extremely rare to have days when a relatively strong and steady wind blows. During the entire summer in my area there were only 4 such days. There were several calm days. And on the rest, the wind was very turbulent, both in speed and direction.

In such conditions, making a “global” wind power generator (1-2 kW or more) is completely pointless. Not only will it never pay for itself, but it will generally work poorly. Because a powerful generator will require large blades, and they will have high inertia and therefore “pass” gusts of strong wind. Those. they simply won’t have time to unwind. Sometimes such gusts, carrying the main power of the “average” wind flow, last only 15-30 seconds.

In addition, any rotating object has a significant moment of inertia in the plane of rotation and is, in fact, a gyroscope. I hope the reader remembers a simple school experiment in demonstrating the gyroscopic effect with bicycle wheel. Once untwisted, it is easily held with literally “two fingers” by one of the protruding ends of its axis. And it is extremely difficult to turn it sideways and make it spin in a different plane. Approximately the same thing will happen to a windmill propeller when the wind direction changes. Both the axle and the propeller blades will experience monstrous lateral alternating loads.

These circumstances actually put an end to hopes of getting by with one large windmill. Of course it will work. But rarely and stupidly. In weak turbulent winds, it will still produce scanty power, and in strong winds, you won’t know what to do with the excess. And of course, you should forget about its payback. It will be just an expensive and beautiful toy, the most stupid investment of money and labor that you can imagine.

Promising wind turbine designs are small, low-power wind generators that have almost zero inertia. They are the ones who are able to take from the wind almost all the energy it carries. Such that they would have time to quickly unwind and practice tack changes. And to receive high power It will be necessary to construct a kind of wind farm of wind generators located on masts of different heights (so as not to shield each other from the wind). This, by the way, will significantly increase storm resistance, solve problems with powerful heavy masts and guy wires (the masts will hold each other), and with the reliability of the “power plant” - after all, all generators cannot break down at once and scheduled repairs and maintenance will not lead to a complete shutdown of generating capacity.

Having come to such disappointing conclusions, I decided to convert my anemometer into a working model of a wind generator. Those. instead of stupidly contemplating a weather vane, start getting practical benefits from it. Moreover, the windmill generator is a stepper motor with 200 “steps” per revolution and generates electricity quite quickly even at low speeds. Generator power is approximately 7-8 Watts

First of all, it was necessary to replace the blades with less inertial ones. The blowers from the fan are still quite heavy. I made new windmill blades from the remains of duralumin casting for plastic windows. The diameter of the propeller is approximately 50 centimeters. This promises maximum power for the generator even with a wind of 4 m/s. I cut a triangle out of thick plywood. I glued a sleeve into it (with epoxy resin), the inner diameter of which coincided with the diameter of the axis of the stepper motor. Having carefully marked it, I made cuts in the plywood “cockpit” and glued the blades into the slots. Additionally, I secured them with small screws. While the epoxy was not hardening, I tried to balance the screw as much as possible so that it did not vibrate when rotating. After the epoxy resin had hardened, I checked the balancing again and brought it to perfection by cutting thin strips of duralumin from the edges of the blades.

Generally speaking, small-sized wind generators have a pleasant property. There is practically no point in bothering with the most complex calculations of KIEV, blade profiles and their manufacture. The simplest, flat ones will work just fine. And the required power can be obtained by simply lengthening them (hence, increasing the sweeping area).

All this makes the wind generator extremely cheaper, and it makes sense to manufacture and use it. In particular, I spent about 3-4 hours on mine (including the weather vane) and did not take into account the polymerization time of the epoxy resin. The costs were “zero”, since everything was made “from garbage”, i.e. scrap materials.

It would seem, where can such a low-power generator be used? In the future, I'm going to use it for... heating water. Or rather, to compensate for the heat loss of water heated by the sun. The simplest calculation shows the absolute validity of my hopes.

Let's say there is a certain tank - a thermos, 50 liters, into which water heated to 50 degrees from the solar collector is drained in the evening. The size of the tank is approximately 40 x 40 x 40 cm. Accordingly, the surface area will be equal to 1 square. meter The tank is surrounded by thermal insulation with TO thermal conductivity 0.15 W/m*deg and thickness 30 cm and heat loss will be approximately 0.5 W/deg. Those. in order to maintain a temperature difference of 20-25 degrees between the hot water in the thermos tank and the surrounding air, a generator with a power of only 10-15 W is sufficient! It will compensate for heat loss and once heated water will never cool down. And if there is a strong breeze, it will also warm up.

Now my generator is spinning without load, undergoing “sea trials”. But in the near future I will force him to charge the batteries in the lighting of the country toilet and the illumination of the path to it. Otherwise, dragging the network cable there is both lazy and difficult, and changing batteries in Chinese lantern I'm already tired of it.

Usually a gentle breeze blows, but my mini windmill periodically spins up very high speed, the propeller rotates at such a speed that it is practically invisible, although at such speeds a barely audible rolling of the blades can be heard. Now this windmill keeps an old but working battery in working condition so that it does not discharge. The maximum power of the windmill is only up to 100mA, perhaps it can produce more, but we usually have a slight wind blowing, and measured it in a normal breeze.

I saw the design of similar windmills on an overseas website and decided to replicate it, and that’s how this baby was born. I used it as a generator stepper motor from my inkjet printer, which had been out of service for a long time and was collecting dust. Having disassembled it, I unscrewed the motor. Then he looked, turned it, twirled it with his hands, measured how much it gave, it gave very little, but the volts rose above 12, which means it could theoretically charge the battery.

Next, I made a mount for the blades from the transistor. The transistor was drilled along the diameter of the shaft on which the gear attachment melted, generally to its dimensions. I put the transistor on the shaft, dropped some glue and twisted it, making sure that everything was smooth. Then I finally fixed it with epoxy. I spread it a little and filled the hole of the transistor, additionally protecting the motor from bad weather by covering the holes in the motor. Below is a photo of this generator.

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Next, I cut out blades from a piece of PVC pipe with a diameter of 110 mm, drew a blank on the pipe, which I cut out with a cutting machine. I took the approximate dimensions: the width was 9cm, and the screw span was 48cm. I drilled holes and screwed the screw to the motor-generator using small bolts.

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For the base, I used a piece of 55th PVC pipe, then cut out the tail from plywood, and added a piece from 110th. Mtorchik glued the pipes in. After assembly, the result was a wind power plant like this. I immediately assembled the rectifier. Since this motor did not want to produce a lot of volts at low speeds, I assembled it using a doubling circuit and turned it on in series.

I took HER307 diodes, capacitors - 3300uF

I wrapped the circuit in polyethylene and inserted a rectifier into the pipe, then a motor and tied it with wire through the drilled holes, covering the space with silicone. I also covered all the holes on top with silicone, and drilled one hole at the bottom, just in case, so that if anything happens, the water would drain out and the condensation would evaporate.

The tail was secured through with a bolt, the semicircular tail was inserted and tied with wire, and it held on firmly. I found the center of gravity, drilled (dia. 9mm.) I also drilled dia. 6mm two M10 bolts, through, under the axle. (The M10 bolts here serve as the “bearing” of the axle) I screwed the M10 bolts into the pipe from above and below, lubricated the long M6 bolt with grease and twisted everything together, it turned out quite rigidly. I screwed the axle bolt (M6) to the corner, and it to the stick. I put a silicone plug on top of the M10 bolt, now the axis is not afraid of water. The wind generator is complete.

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I took several blocks for the mast. which he twisted with self-tapping screws, secured to the windmill and lifted onto the rope. I connected it to the battery, it is charging, but it is very weak, it keeps the battery from naturally discharging. Since the wind was spinning, I was satisfied, at least I’ll know which way the wind is blowing. This option - as stated on that site - is a little weekend project, that is, a small project for the weekend, for the pleasure of picking something up, especially since I don’t I spent not a penny... glue doesn't count. So, in theory, it can light a couple of small LEDs, or charge a mobile phone in a couple of days, but most likely the phone will take such a weak current for a bad contact and turn it off, writing bad connection on the display.

In the future, if I have time and desire, I can do it for lighting the yard, but I’ll just assemble a second one like this and install a small battery, or several rechargeable batteries. For this, there is one more stepper left, only this one produces 2x20 volts when cranked by hand, but the current is small. And the second one is on the brushes, immediately permanent. By hand 10 volts, short circuit - 0.5 Ampere. And I’ll still be torturing the autogenerator, but I’ll just wait for the magnets.

The power supply to country houses, country houses or cottage villages is often unstable. The lines are worn out, interruptions from accidents or broken wires occur much more often than we would like. It does not take much time to correct the damage, but small gaps create a lot of inconvenience. The solution to the issue could be an installation capable of providing energy to the main consuming devices.

DIY mini wind generator

The size of a wind generator does not necessarily have to amaze the imagination with its grandeur. A small installation made from small improvised parts or devices is also capable of generating current. She might become teaching aid for children, a lighting source for emergency situations, battery charger mobile phone etc.

Costs are reduced tenfold, and the efficiency is the same as what was envisioned when the project was created. A mini-wind generator can serve as a trial model to test the technology and gain some experience in creating such devices. For production, you can use a variety of failed or outdated equipment.

We use an old computer cooler

For windmill manufacturing you need a big cooler, it gives out top scores and easy to use. First of all, you need to disassemble it. The sticker is removed, the plug and the retaining ring are removed. After this, the cooler can be easily disassembled along the axis of rotation into two halves approximately equal in size.

One of them is the rotor, the blades of which will have to be changed to larger ones. To do this, carefully break off or cut off the old blades from plastic bottle new ones are made, about 4 times longer than the previous ones. It is most convenient to make three pieces; they will have sufficient base area for strong gluing.

The stator has four windings. They can be left intact, or the number of turns can be changed. A thinner wire is taken and wound around everything in turn, and in different directions. The coils are connected accordingly.

After this, you need to make a rectifier, which will require four diodes. They are connected in pairs in series, then in parallel. The wires are connected, the device is ready. To install it in the wind, you will need a stand or a small mast, which is most easily made from a piece of metal tube. In order for the windmill to point itself into the wind, you will need a tail stabilizer, like an airplane tail.

A tester or LED flashlight is attached to check the functionality.

Device for charging a car battery

A small wind generator that can charge car battery- a very practical and necessary device. It is necessary to provide a voltage that does not exceed the battery rating (usually 12 V), otherwise there is a risk of overcharging and boiling of the battery.

As a generator you will need homemade device appropriate power or ready asynchronous motor, tractor or car generator, capable of creating a charge voltage. To protect against overcharging, you will need a controller based on a car relay-regulator that turns off the charge when the voltage is too high.

Camping wind generator

Have camping windmill, allowing you to get maximum comfort from being in nature, convenient and useful for every travel lover. The requirements for such a windmill are obvious:

• compactness
• Possibility of quick assembly or disassembly for transportation
• power that provides electricity to the necessary devices

You will need to make an impeller with detachable blades and a generator that produces sufficient power. The best option- horizontal type, with blades on screws. The generator is best adapted from a car; it needs a little modernization (rewinding the coils) and installing magnets on the rotor (neodymium magnets are used to excite the windings).

In nature, it is enough to mount the device on a tree trunk or other suitable support and point it into the wind. For compactness, you can not make a device for rotating around a vertical axis and adjust the position manually.

Windmill from a stepper motor from a printer

Stepper motors are capable of delivering 12 volts or more, but their current strength is low. The design does not allow strengthening their windings, so they are used as is. Blades of the appropriate size, made from polypropylene sewer pipes, are installed on the shaft. You will need to assemble a simple rectifier. Conventional stepper motors, in theory, are capable of charging a mobile phone battery in a couple of days, but in practice this is very difficult to achieve; they can be used for illumination using LED flashlights.

Other possible options

For manufacturing a mini wind generator You can use any electric motors from household appliances. You can adapt the motor from a tape drive mechanism, from an old microwave oven (fan), and different options for brush designs. They all have low power and will not be able to provide any serious devices, but as trial models created together with children and providing experience and understanding of the process, all these options are quite suitable.

Based on the knowledge and skills gained, a more productive wind generator can be created that can meet the needs of a private home and transfer it to an autonomous power supply mode.