An electric generator is a device designed to generate electricity used for specific purposes. A homemade device is capable of performing the function of a source only if certain conditions are met. It is unlikely that it will be possible to assemble it completely from scratch at home. The only way to make an electric generator with your own hands is to use for these purposes other mechanisms that work on the same principle. An old engine from a walk-behind tractor or wind turbine is most suitable. Assembly work will require a lot of effort and money, as well as certain experience. If you are not completely confident in success, it is best to purchase an expensive but effective branded product.
Design and principle of operation
DC generator
Before you make an electric generator with your own hands at home, you will need to familiarize yourself with its design and understand how it works. The basis of such a device is a multi-section winding located on a stationary stator. A movable armature (rotor) is placed inside, the design of which includes a permanent magnet. This part of the generator is connected through a special drive mechanism to a propulsion device driven into rotation by a windmill or gasoline engine. It is allowed to use alternative energy resources as a drive (water or heat generated by the combustion of wood, for example).
Operating procedure:
- when the rotor rotates, its magnetic lines cross the e/m field of the stator coils;
- thanks to this, according to Faraday’s law of induction, an EMF of the appropriate magnitude is induced in them;
- a load is connected to the stator coils, the alternating current in which varies in a sinusoidal manner.
Depending on the number of stator windings and the connection circuit, you can get single-phase 220 Volts or three-phase (380 Volts) homemade generator.
This principle of operation applies to all types of electrical machines without exception (regardless of the type of drive).
Efficiently running generator electric current, made with your own hands from auxiliary parts, is capable of solving a number of everyday problems. Homemade products are traditionally used to generate enough electrical energy to power a home's electrical system. In addition, the unit can operate not very powerful welding equipment or a water pump for watering garden beds. Made in the form wind generator The product can be used in the country and on a hike.
DIY generator assembly
The instructions for assembling current generators with your own hands involve performing work in several stages. They begin with the preparatory stage, at which it is necessary to stock up on initial blanks and the required material.
Preparatory stage
Mole walk-behind tractor engine
For assembly you will need:
- An old electric motor from a walk-behind tractor or windmill with a working stator winding. Also popular are the options for using engines from old washing machine or water pump.
- To equalize the output current, it is advisable to make a rectifier (converter) in advance.
- To facilitate the launch of the future device and self-excitation of its 220 Volt windings, a high-voltage (at least 400-500 Volt) capacitor with a capacity of 3-7 microfarads will be required. Its exact value is selected depending on the planned power of the generator.
For assembly you will need long pieces of wire in reliable insulation, adhesive protective tape and installation tools (side cutters, pliers and a set of screwdrivers). You should also stock up on a powerful soldering iron, which is necessary to restore contacts in damaged windings of an old motor.
You should take care in advance about grounding the case of the future product that generates a voltage that is dangerous to humans.
Upon completion of preparation, they proceed to assembly, the order of which depends on the selected initial sample.
Windmill - the simplest option
DIY wind generator diagram
The easiest way to implement it is to make a wind generator assembled from scrap parts and ready-made modules. It can operate very simple electrical loads, the power of which does not exceed 100 Watts (a light bulb, for example). To make it you will need:
- (it will work as a generator).
- The carriage and main sprocket are from an adult bicycle.
- Roller chain from an old motorcycle.
- Bicycle frame.
A good craftsman will probably find all these improvised materials in his garage; he can easily assemble an electric generator from them with his own hands.
To familiarize yourself with this procedure, it is advisable to watch a video that describes in detail the procedure for making a windmill.
A sprocket is installed on the shaft of such an electric motor, which is driven into rotation by means of a roller chain from homemade wind blades mounted on bicycle frame. With their help, the translational movement of the wind is converted into rotational moment. This design is capable of generating current in a load of up to 6 Amperes at a voltage of 14 Volts.
Power plant based on a generator from a walk-behind tractor
Structure of a generator from a walk-behind tractor
A more complex option involves the use of an old walk-behind tractor used as a drive. The generator function in this system is performed by an asynchronous motor with a rotation speed of up to 1600 rpm and an effective power of up to 15 kW. During the assembly process, its drive mechanism is connected to the axis of the walk-behind tractor through pulleys and a belt. The diameter of the pulleys is selected so that the rotation speed of the electric motor converted into a generator is 15% higher than the rated value.
Advantages and disadvantages
Unlike factory ones, homemade gasoline generators made at home usually have large dimensions and weight
To the merits of the collected manually products should be classified as:
- The ability to not depend on interruptions in the operation of supply substations, receiving minimum required electricity yourself.
- The homemade generator is configured to operating parameters that meet the user’s specific needs.
- Its manufacture instead of a purchased product will allow you to save significant amounts (especially in the situation with 380 Volt asynchronous machines).
The disadvantage of self-production is considered possible difficulties with the assembly of a specific type of product and the need to spend money on energy resources (fuel, for example).
Before you make a household electricity generator, you need to familiarize yourself with the rules of its operation. Their essence is as follows:
- Before starting the device, all loads are turned off to allow it to run idle.
- The presence of oil in the working compartment of the generator is checked - its level should be above the set level;
- The device remains turned on for approximately 5 minutes, after which the load can be connected.
In accordance with the rules for the operation and care of such generators, the most suitable operating mode is considered to be using its power at 70% of the maximum value. If this requirement is met, the equipment will not overheat and can easily cope with the design load.
Very often, lovers of outdoor recreation do not want to give up amenities Everyday life. Since most of these conveniences involve electricity, there is a need for a power source that you can take with you. Some people buy an electric generator, while others decide to make a generator with their own hands. The task is not easy, but it is quite doable at home for anyone who has technical skills and the necessary equipment.
Selecting a generator type
Before you decide to make a homemade 220 V generator, you should think about the feasibility of such a decision. You need to weigh the pros and cons and determine what suits you best - a factory sample or a homemade one. Here main advantages of industrial devices:
- Reliability.
- High performance.
- Quality assurance and access to technical support.
- Safety.
However, industrial designs have one significant drawback - a very high price. Not everyone can afford such units, so It’s worth thinking about the advantages of homemade devices:
- Low price. Five times, and sometimes more, lower price compared to factory electric generators.
- Simplicity of the device and good knowledge of all components of the device, since everything was assembled by hand.
- The ability to modernize and improve the technical data of the generator to suit your needs.
A home-made electric generator is unlikely to be any different. high performance, but it is quite capable of providing minimal requests. Another disadvantage of homemade products is electrical safety.
It is not always highly reliable, unlike industrial designs. Therefore, you should take the choice of the type of generator very seriously. Not only savings will depend on this decision Money, but also life, the health of loved ones and oneself.
Design and operating principle
Electromagnetic induction underlies the operation of any generator that produces current. Anyone who remembers Faraday's law from the ninth grade physics course understands the principle of converting electromagnetic oscillations into direct electric current. It is also obvious that creating favorable conditions for supplying sufficient voltage is not so easy.
Any electric generator consists of two main parts. They may have different modifications, but are present in any design:
There are two main types of generators depending on the type of rotor rotation: asynchronous and synchronous. When choosing one of them, take into account the advantages and disadvantages of each. Most often, the choice of folk craftsmen falls on the first option. There are good reasons for this:
In connection with the above arguments, the most likely choice for self-production is asynchronous generator. All that remains is to find a suitable sample and a scheme for its manufacture.
Unit assembly procedure
First, you should equip your workplace with the necessary materials and tools. Workplace must comply with safety regulations when working with electrical appliances. The tools you will need are everything related to electrical equipment and vehicle maintenance. In fact, a well-equipped garage is quite suitable for creating your own generator. Here's what you'll need from the main parts:
Having collected necessary materials, begin to calculate the future power of the device. To do this, you need to perform three operations:
When the capacitors are soldered in place and the desired voltage is obtained at the output, the structure is assembled.
In this case, the increased electrical hazard of such objects should be taken into account. It is important to consider proper grounding of the generator and carefully insulate all connections. Not only the service life of the device, but also the health of those who use it depends on the fulfillment of these requirements.
Device made from a car engine
Using the diagram for assembling a device for generating current, many come up with their own incredible designs. For example, a bicycle or water-powered generator, windmill. However, there is an option that does not require special design skills.
Any car engine has an electric generator, which is most often in good working order, even if the engine itself has long been scrapped. Therefore, after disassembling the engine, you can use the finished product for your own purposes.
Solving a problem with rotor rotation is much easier than thinking about how to make it again. You can simply restore a broken engine and use it as a generator. To do this, all unnecessary components and accessories are removed from the engine.
Wind dynamo
In places where the winds blow without stopping, restless inventors are haunted by the waste of nature's energy. Many of them decide to create a small wind power plant. To do this, you need to take an electric motor and convert it into a generator. The sequence of actions will be as follows:
Having made his own windmill with a small electric generator or a generator from a car engine with his own hands, the owner can be calm during unforeseen disasters: there will always be electric light in his house. Even after going outdoors, he will be able to continue to enjoy the conveniences provided by electrical equipment.
Many people use a gasoline generator in their work and everyday life. Today the market is saturated with such devices and you need an idea of what is available and what is needed to guide your choice.
The gasoline generator is autonomous system power supply, which uses gasoline as the fuel consumed.
Classification of gasoline generators.
Gas stations can be classified according to several criteria. Each generator is ready to operate under certain conditions and at certain voltages.
- Professional and home;
- Portable and stationary;
- Two-stroke and four-stroke;
- Single-phase and three-phase;
- Power: up to 4 kW, up to 15 kW, up to 30 kW.
Household generators are ideal for private homes or long trips into nature.
The use of professional units is necessary so that companies can connect complex tools.
Portable models have low power(up to 5 kVA), weight and dimensions, which allows them to be moved to another location.
Two-stroke engines are installed on low-energy gasoline units, the power of which does not exceed 1 kW. In all other cases, a four-stroke engine is installed.
Most residential consumers may be limited to a single-phase electrical generator.
Three-phase is much more expensive, and not the fact that its functionality will ever be in demand. At the same time, most single electrical networks are powered by single-phase current.
- Domestic power plants.
Power does not exceed 4 kW. This is enough to provide electricity a private house, warehouse or smaller workshop. Gasoline generators of this type are not designed for 24-hour operation.
The longest period of continuous operation is 4 hours. The cooling system must then be provided and then restarted.
- Industrial BSU. They have a power of up to 15 kW. Suitable for trade organizations and construction sites. Increased performance extends the continuous operating time of the generator to 10 hours.
Among diesel generators of the same class, BGU is characterized by lighter weight and dimensions.
- Gas station with power up to 30 kW most often used for power supply in office buildings or in large warehouses. These devices are permanently installed in pre-prepared premises.
Gasoline generator.
A gas generator is similar to a diesel unit.
The key element of the device is the engine.
Two types of motors can be used:
- Push-pull.
They are installed in low-energy installations for short-term operation.
- Four stroke. They have an increased margin of safety. Period uninterrupted operation is 5-7 hours. Engine source - 3-4 thousand hours.
The engine is equipped various systems. One of them is responsible for the supply of fuel, the second is for preventing noise, the third is for supplying lubricants. There is also a kit in the exhaust pipe.
The output of the motor determines the type of generator used - single-phase or three-phase.
If the planned load exceeds 5 kW, the power plant is equipped with a three-phase generator.
In addition, generators can be asynchronous or synchronous.
Some budget models are equipped with asynchronous generators, which have a simple design.
Synchronous generators can withstand three months of stress.
The quality and flawless operation of the key internal blocks of the electric generator are monitored by instruments.
The gas generator diagram shows the location of all electrical installation blocks and their effect on the operation of the device. The structural structure of the structure connects all the nodes in one working complex.
The principle of operation of a gasoline generator.
To ensure the quality and timely operation of the device and to identify possible problems, you need to have an idea of how a power generator works.
The operating principle of a gasoline generator is as follows.
The power of a gasoline generator is determined by the number of turns of the stator winding.
The power of gasoline mini-power plants usually does not exceed 12 kW.
Increase generator power by 2 times
When generators with an excitation coil came into use to produce direct current, the cost of semiconductor diodes was quite high, so in order to save money they used traditional scheme by connecting the windings of a three-phase generator, called a star.
At that time, few people were concerned about the fact that sometimes the coils worked out of phase, since the main thing was considered to be what was cheaper.
Today, semiconductor diodes for generators DC generators with an excitation coil are much cheaper compared to the rest of the generator design. In this regard, an increase in the number of diodes will not lead to a significant increase in the cost of the product, while it is also possible to reduce the size of the generator itself, which will lead to a significant reduction in its mass and overall cost.
Let's consider the developed and tested original circuit for connecting diodes and windings of a DC generator.
Thanks to modern electronic components, it is possible to select diode bridges of sufficient power in miniature housings.
In this regard, it is possible to replace the 6 diodes under the generator cover with 3 powerful diode bridges.
In practice, this device was tested on a motorcycle generator with an initial rated power of 150 watts.
An amazing result was obtained. To consider all the nuances, a test bench for the generator was developed. Analyze the results of the tests carried out according to increasing generator power.
The readings located below the line are responsible for the battery discharge, and those above are responsible for the charge.
The ignition system was not taken into account during the measurements, which means that the standard generator located in the electrical circuit of the motorcycle is not able to feed 200-watt lamps. The uprated generator performed well at 200 watts in city driving and at 400 watts on the freeway. Heating of the stator coil was noted, which never exceeded more than 100 degrees.
Making a gas generator with your own hands
Note that the reins can withstand up to 120 degrees. In practice, it turned out that a high-quality diode bridge requires only a good radiator, and if you do not use the generator at a load of 400 watts while the motorcycle is idle, then you will not need to install an impeller.
As a result, the design is lightened by one part, which previously bothered me with an additional ringing sound, easily audible on the stand.
Using this winding connection circuit, you can increase generator power without design changes from 200 to 500 watts.
How to make a 12 volt gas generator
You can, of course, buy any regular 220-volt gas generator and connect the charger and it will be a gas generator with a 12-volt output. But if you are looking for a 12-volt gas generator, then you want to have more battery charging power, and at the same time have a high charge efficiency.
I personally tried the first option with a charger.
I have a 1 kW gas generator, and I connected a transformer car charger to it. It could produce a charge current of up to 10-12A, but it overheated greatly. In this way, in an hour of operation of the gas generator, I was able to “fill” the battery with only 120 watts of energy.
This is very little, and in an hour the gas generator consumes more than 0.5 liters of gasoline.
To charge a dead 120Ah battery, I will have to run a gas generator for 10 hours, which is at least 6 liters of gasoline, and I will only store 1 kW of energy.
I tried to install a pulse charger, but it burned out due to the excess voltage of the gas generator. The fact is that these pulse chargers can withstand a maximum of 260-270 volts.
Homemade generator
And if you disconnect the load from the gas generator, it cannot sharply reduce speed, and for a short time the voltage without load rises to 300 volts. This is what kills pulse chargers, but transformer chargers don’t care about it.
By the way, my gas generator had an output of 12 volts 10A. But in fact, it provided a charge current of only 5-6A and the built-in current protection was constantly triggered; in short, this option turned out to be a useless option.
There are no 12 volt gas generators on sale at all, there are only expensive welding generators. And I decided to remake my gas generator to charge 12 volt batteries.
Below is the video of the first tests of the gas generator. I didn’t do it in my own building; it wasn’t possible to place the generator there due to the belt drive.
I used a 14V 60A car generator.
In this option, I received an average charge current of 25A, while the engine speed was only about 1500 rpm, which is two times lower than it worked before with a 220V generator. The engine has become quieter, has become much more economical in gasoline, and at the same time, per hour of operation of the gas generator it is possible to produce about 400 watts of energy.
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In general, if you add engine speed, the generator easily produces 40-50A of charge current. You can install a 90A generator and get 1kWh of power. I sometimes charge my batteries with such a converted gas generator. solar power plant. So far I’m happy with everything, the charging current is 25A at low generator speeds.
By the way, a car generator does not need to be altered at all, and at the same time, it already has a built-in charge regulator, so you will not overcharge the batteries.
Connecting the generator to the battery like in a car.
There are quite a lot of photos and videos on the Internet about homemade 12 volt generators. For example
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Also a 12 volt gas generator from a chainsaw and a car generator
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There are many options for manufacturing such gas generators.
The chainsaw will probably be the most cheap option, but not very durable and reliable. The best thing is that this is an engine from a walk-behind tractor; you can connect a powerful car generator to it via a belt.
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What can you use to assemble an electric generator with your own hands?
Unfortunately, domestic power supply organizations do not keep their word.
Their contracts signed with consumers are worthless. The supply of electricity outside large cities is inconsistent, the quality of the supplied current is low (meaning voltage), so residents of small towns and villages always have candles and kerosene lamps in stock, and the most advanced ones install gasoline power generators.
In this article, another option will be proposed, which will be indicated by the question, how to make an electric generator with your own hands? Let's look at one version of this device.
Electric generator from a walk-behind tractor
Residents of suburban villages have been using walk-behind tractors for a long time.
After all, today this is, so to speak, the most reliable assistant, without which work in the garden or garden cannot be carried out. True, like all tools of this type, the walk-behind tractor fails. It can be restored, but as practice shows, it is better to buy a new one.
The owners of the instrument are in no hurry to say goodbye to it, so every owner of a country house has one old copy in their closet. It will be possible to use it in the design of an electric generator with a voltage of 220/380 volts.
It will create torque to the current generator, which can be used as an ordinary asynchronous motor. In this case, a powerful electric motor will be required (at least 15 kW, with a shaft speed of 800-1600 rpm).
Why is the electric motor so powerful?
There is no point in making a homemade generator for a couple of light bulbs, because the issue of fully providing a country house with electricity is being resolved. But with a low-power electric motor, you won’t be able to get enough electricity.
Although it all depends on the total power of household appliances and lighting of the house. After all, in small dachas There is nothing except a refrigerator with a TV. Therefore, the advice is to first calculate the power of the house, then choose an electric motor-generator.
Electric generator assembly
So, to assemble a 220-volt gasoline generator with your own hands, you need to install a walk-behind tractor and an electric motor on the same frame so that their shafts are parallel.
The thing is that the rotation from the walk-behind tractor to the electric motor will be transmitted using two pulleys. One will be installed on the shaft of a gasoline engine, the second on the shaft of an electric one. In this case, it is necessary to select the correct pulley diameters. It is these dimensions that determine the rotational speed of the electric motor. This indicator must be equal to the nominal one, which is indicated on the equipment tag.
A slight upward deviation of 10-15% is welcome.
When the mechanical part of the assembly is completed, the pulleys connected by the belt will be installed, you can move on to the electrical part.
Electric generator device
- First, the windings of the electric motor are connected in a star configuration.
- Secondly, the capacitors connected to each winding must form a triangle.
- Thirdly, the voltage in such a circuit is removed between the end of the winding and the midpoint.
It is here that a current of 220 volts is obtained, and between the windings 380 volts.
Attention! Installed in electrical diagram capacitors must have the same capacitance. In this case, the size of the capacitance is selected depending on the power of the electric motor. It is this ratio that will support the correct operation of the current generator itself, but especially its start-up.
For information, we give the ratio of motor power to capacitor capacity:
- 2 kW – 60 µF.
- 5 kW – 140 µF.
- 10 kW – 250 µF.
- 15 kW – 350 µF.
Please note some useful tips given by experts.
- If Electrical engine will heat up, then it is necessary to change the capacitors to elements with a reduced capacity.
- Typically, for homemade electric generators, capacitors with a voltage of at least 400 volts are used.
- Usually one capacitor is enough for a resistive load.
- If there is a need to use all three phases of the electric motor to power the house, then it is necessary to install a three-phase transformer in the network.
And one moment.
If you are faced with the problem of how to organize heating using a homemade electric generator, then the engine from the walk-behind tractor here will be small (meaning the power of the device).
The best option is an engine from a car, for example, from an Oka or a Zhiguli. Many may say that such equipment will cost a pretty penny. Nothing like this. Today you can buy a used car for just pennies, so the costs will be minimal.
Advantages and disadvantages
So, what are the advantages of this device:
- You console yourself with the thought that you did it yourself.
That is, you are proud of yourself.
- Financial costs are reduced to a minimum. Homemade unit will cost much less than its factory counterpart.
- If all stages of assembly are carried out correctly, then the electrical equipment assembled by your own hands can be considered reliable and quite productive.
Some negative points this type of devices.
- If you are new to electrics or are trying to make a current generator without delving into all the intricacies and nuances of the assembly, then you will fail.
In principle, this is what it is the only drawback, which inspires optimism.
Other electric generator designs
The petrol option is not the only one.
There are different ways to make an electric motor shaft rotate. For example, using a windmill or water pump. Not the best simple designs, but they are the ones that allow us to move away from consuming the energy carrier in the form of gasoline.
For example, assembling a hydrogenerator with your own hands is also not difficult. If a river flows near the house, its water can be used as a force to rotate the shaft.
To do this, a wheel with many containers is installed in its channel. Using this design, it is possible to create a flow of water that will rotate a turbine attached to the shaft of an electric motor. And the larger the volume of each container, the more often they are installed (the number increases), the greater the power of the water flow. In essence, this is a kind of generator voltage regulator.
With wind generators, things are a little different because wind loads are not constant quantities.
The rotation of the windmill, which is transmitted to the shaft of the electric motor, must be regulated, adjusting it to the required speed of the electric motor shaft.
Therefore, in this design, the voltage regulator is a regular mechanical gearbox. But here, as they say, it’s a double-edged sword. If the wind reduces gusts, a step-up gearbox is needed; if, on the contrary, it increases, a step-down gearbox is needed.
This is the difficulty of constructing a wind power generator.
Conclusion on the topic
To summarize, you need to understand that homemade electric generators not a panacea.
We assemble and connect electric generators for the home with our own hands
It is better to ensure that electric current is constantly supplied to the village. This is difficult to achieve, but you can get compensation for inconvenience through the court. And the money already received will be used to purchase a factory gasoline generator. True, you will have to take into account the consumption of expensive fuel (gasoline).
But if you want to assemble an electric generator with your own hands, then delve into the topic and try.
How to properly connect a 380 to 220 volt electric motor
How to make a generator from an asynchronous motor with your own hands
Design and principle of operation of a three-phase asynchronous motor
Generator sets
A generator set, or, as it is usually called, a generator, is the main source of electrical current in a car. It should be noted that the generator set includes not only the generator as such, but also its drive, as well as devices for regulating and converting the generated voltage.
Generators are electrical machines that transform mechanical energy to electric.
In principle, electrical energy generators are machines that convert any type of energy - thermal, nuclear, chemical, light, etc. into electrical energy. But traditionally, generators are usually called machines that convert mechanical energy of movement into electricity. 
Most often, for such a conversion, generators use the mechanical energy of rotation of one of the structural elements, called an armature or rotor.
It is fundamentally possible to convert the mechanical energy of the translational motion of any body into electrical energy, but this type of generator is not used in practice due to the complexity of the design and low efficiency.
A car generator receives mechanical energy from the engine crankshaft, which is connected to a drive, most often a V-belt or flat-belt drive.
The electrical energy obtained as a result of the operation of the generator is used to power the vehicle's electrical consumers - the ignition, lighting and alarm systems, electric drives and instrumentation, computer devices, etc., as well as for charging battery.
Since the number and total power of electricity consumers in modern cars is progressively growing, the generators used to generate electrical energy have high power, which can reach 1 kW or even more.
The generator “takes away” this power from the engine, reducing its dynamic and economic performance. Nevertheless, we have to put up with such losses, since a modern car, even a diesel one, will not go far without electrical energy.
Cars can use constant or constant generators. alternating current.
History of the invention of the generator
The operation of a generator that converts mechanical energy into electricity is based on the phenomenon of magnetoelectric induction, which is usually (and not entirely correctly) called the phenomenon of electromagnetic induction.
Electromagnetic induction is the phenomenon of the occurrence of electric current in a closed circuit when the magnetic flux passing through it changes. In practice, this can be achieved, for example, by moving a metal frame in a magnetic field created by a permanent magnet.
The phenomenon was discovered and described by the English physicist Michael Faraday (1791–1867) in 1831.
Many scientists studied the nature of electrical phenomena when a conductor is exposed to a permanent magnet, but Faraday was the first to publish his experiments and draw the appropriate conclusions.
Analyzing the results of experiments on the study of electromagnetic induction, Faraday discovered that the electromotive force arising in a closed conducting circuit is proportional to the rate of change of the magnetic flux through the surface limited by this circuit.
The magnitude of the electromotive force (EMF) does not depend on what is causing the flux change - a change in the magnetic field itself or the movement of the circuit (or part of it) in the magnetic field.
The electric current caused by this emf is called induced current.
The occurrence of EMF is explained by the action of magnetic field forces on free electrons located in conductors, which begin to move directionally, accumulating at one end of the conductor.
As a result of this movement of electrons, a negative signal will appear at one end of the conductor. electric charge, and at the other end - positive.
The potential difference at the ends of the conductor is numerically equal to the EMF induced in the conductor.
The induction of EMF in a conductor occurs regardless of whether it is included in any electrical circuit or not. If you connect the ends of this conductor to any receiver of electrical energy, then under the influence of a potential difference, an electric current will flow through a closed circuit.
It is believed that the first electric current generator, based on the phenomenon of electromagnetic induction, was built in 1832.
Parisian inventor Hippolyte Pixii, 1808–1835. This generator was suitable only for demonstration purposes and not for practical use, since it was necessary to manually rotate a heavy permanent magnet, due to which an alternating electric current arose in two wire coils fixed motionless near its poles.
Subsequently, the Pixie generator was improved and began to be used in various fields of mechanical engineering.
DC Generators
Until the 1960s, the main source of power for cars was DC generators, which, as the name suggests, convert mechanical energy into DC electrical energy.
A direct current generator consists of a stator - a stationary housing with electromagnetic elements housed in it, a rotating armature with windings, and a commutator with a brush assembly.
The armature is equipped with several windings of current-carrying coils, which, when the armature rotates, cross the magnetic field of a stationary stator, as a result of which an electromotive force (EMF) is induced in the windings.
The magnitude of the EMF in the windings when the armature rotates constantly changes in magnitude and direction depending on the position of the coils relative to the stator magnetic field.
Through the collector unit, the EMF induced in the stator windings is removed into the electrical circuit for further processing and reduction to the required parameters.
The operating principle of a direct current generator is based on the fact that if a current-carrying frame with open ends is rotated in a constant magnetic field, an emf is induced in it, and a potential difference appears at its ends of the frame.
A simplified circuit of a direct current generator is shown in Fig. 1.
A steel cylindrical core rotates in the magnetic field of a permanent magnet, in the longitudinal grooves of which a diametrical coil abcd is placed.
The beginning d and the end a of this turn are connected to two mutually insulated copper half-rings, forming a commutator which rotates with the steel core.
Fixed contact brushes A and B slide along the commutator, from which wires extend to the energy consumer R.
A steel core with a turn (winding) and a collector forms the rotating part of a direct current generator - the armature.
If you rotate the armature with the help of some external force, the sides of the coil will intersect the magnetic field, and an emf will arise in the armature windings, the value of which is determined by the formula:
where B is induction; l is the length of the side of the turn; v is the speed of movement of the groove sides of the coil.
Since the length and speed of movement of the slot sides of the armature winding are unchanged, the EMF of the armature winding is directly proportional to B, and the shape of the EMF graph is determined by the law of distribution of magnetic induction B located in the air gap between the surface of the armature and the pole of the magnet itself.
So, for example, the magnetic induction at the gap points lying on the pole axis has maximum values (Fig. 2, a): under the north pole (N) - a positive value and under south pole(S) – negative. At points n and n' lying on a line passing through the middle of the interpolar space, the magnetic induction is zero.
Let us assume that the magnetic induction in the air gap of the circuit under consideration is distributed sinusoidally:
B = Bmax×sinα.
Then the EMF of the coil when the armature rotates will also change according to a sinusoidal law.
How to make an electric generator yourself
Angle α determines the change in position of the anchor relative to the original position.
In Fig. 2, a shows a number of positions of the turn abcd (winding) at different times during one revolution of the armature.
At α = 360˚ the armature emf is zero, and at α = 270˚ it has a maximum value, and a negative one.
Thus, an alternating EMF is induced in the armature winding of the DC generator, and, therefore, when a load is connected, an alternating current will act in the winding (Fig.
2, b – line 1).
During the second half-turn of the armature, when the EMF and current in the armature winding are negative, the EMF and current in the external circuit of the generator (in the load) do not change their direction, i.e., they remain positive, as during the first half of the armature revolution.
Indeed, at α = 90˚, brush A is in contact with the commutator plate of conductor d, located under the N pole, and has a positive potential, and brush B has a negative potential, since it is in contact with the commutator plate connected to side a of the turn, located under the S pole .
At α = 270˚, when sides a and d are swapped, brushes A and B retain their polarity unchanged, since the half-rings of the commutator have also swapped places and brush A still has contact with the commutator plate connected to the side under pole N , and brush B is connected to the commutator plate, connected to the side located under the pole S.
As a result, the current in the external circuit does not change its direction (Fig. 2, b - line 2), i.e. the alternating current of the armature winding is converted into direct current using the commutator and brushes.
The current in the external circuit is constant only in direction, but its magnitude varies, i.e.
That is, it pulsates, as shown in the graph in Fig. 2, b.
Current ripple and EMF are significantly weakened if the armature winding is made of large number turns evenly spaced and distributed over the surface of the core and increase the number of collector plates accordingly.
For example, in two turns on the armature core (four groove sides), the axes of which are shifted relative to each other at an angle of 90˚, and four plates in the collector (Fig. 3, a).
In this case, the current in the external circuit of the generator pulsates at twice the frequency, but the pulsation depth is much less (Fig.
3, b). If there are from 12 to 16 turns in the armature winding, then the current at the output of the generator is almost constant.
In Fig. Figure 4 shows the design of a DC generator.
Alternators
Universal use of electricity in all areas human activity associated with searches free electricity. Because of this, an attempt to create a generator became a new milestone in the development of electrical engineering free energy, which would significantly reduce the cost or reduce to zero the cost of generating electricity. The most promising source for realizing this task is free energy.
What is free energy?
The term free energy arose during the time of large-scale introduction and operation of engines internal combustion, when the problem of obtaining electric current directly depended on the coal, wood or petroleum products spent for this. Therefore, free energy is understood as a force for the production of which there is no need to burn fuel and, accordingly, consume any resources.
First attempts scientific justification the possibilities of obtaining free energy were laid down by Helmholtz, Gibbs and Tesla. The first of them developed the theory of creating a system in which the generated electricity should be equal to or greater than that spent for the initial start-up, that is, obtaining a perpetual motion machine. Gibbs expressed the possibility of obtaining energy by flowing chemical reaction so long that it is enough for a full power supply. Tesla observed energy in all natural phenomena and proposed a theory about the presence of ether, a substance that permeates everything around us.
Today you can observe the implementation of these principles to obtain free energy in. Some of them have long been at the service of humanity and help to obtain alternative energy from wind, sun, rivers, ebbs and flows. These are the same solar panels, hydroelectric dams that helped harness the forces of nature that were freely available. But along with already proven and implemented free energy generators, there are concepts of fuel-free engines that try to circumvent the law of conservation of energy.
The problem of energy conservation
The main stumbling block in obtaining free electricity is the law of conservation of energy. Due to the presence of electrical resistance in the generator itself, connecting wires and other elements of the electrical network, according to the laws of physics, there is a loss of output power. Energy is consumed and to replenish it, constant external replenishment is required, or the generation system must create such an excess of electrical energy that it is enough to both power the load and maintain the operation of the generator. From a mathematical point of view, the free energy generator must have an efficiency greater than 1, which does not fit into the framework of standard physical phenomena.
Circuit and design of the Tesla generator
Nikola Tesla became the discoverer of physical phenomena and based on them created many electrical devices, for example, Tesla transformers, which are used by humanity to this day. Over the entire history of his activities, he has patented thousands of inventions, among which there is more than one free energy generator.
Rice. 1: Tesla Free Energy Generator
Look at Figure 1, this shows the principle of generating electricity using a free energy generator made from Tesla coils. This device involves obtaining energy from the ether, for which the coils included in its composition are tuned to a resonant frequency. To obtain energy from the surrounding space in this system, the following geometric relationships must be observed:
- winding diameter;
- wire cross-section for each winding;
- distance between coils.
Known today various options the use of Tesla coils in the design of other free energy generators. True, it has not yet been possible to achieve any significant results from their use. Although some inventors claim the opposite, and keep the results of their developments in the strictest confidence, demonstrating only the final effect of the generator. In addition to this model, other inventions of Nikola Tesla are known, which are generators of free energy.
Magnetic free energy generator
The effect of interaction between a magnetic field and a coil is widely used in. And in a free energy generator, this principle is used not to rotate a magnetized shaft by applying electrical impulses to the windings, but to supply a magnetic field to an electric coil.
The impetus for the development of this direction was the effect obtained by applying voltage to an electromagnet (a coil wound on a magnetic circuit). In this case, a nearby permanent magnet is attracted to the ends of the magnetic circuit and remains attracted even after turning off the power from the coil. A permanent magnet creates a constant flow of magnetic field in the core, which will hold the structure until it is torn off by physical force. This effect was used to create a permanent magnet free energy generator circuit.
Rice. 2. Operating principle of a magnetic generator Look at Figure 2, to create such a free energy generator and power the load from it, it is necessary to form a system of electromagnetic interaction, which consists of:
- trigger coil (I);
- locking coil (IV);
- supply coil (II);
- support coil (III).
The circuit also includes a control transistor VT, a capacitor C, diodes VD, a limiting resistor R and a load Z H.
This free energy generator is turned on by pressing the “Start” button, after which the control pulse is supplied through VD6 and R6 to the base of transistor VT1. When a control pulse arrives, the transistor opens and closes the circuit of current flow through the starting coils I. After which the electric current will flow through the coils I and excite the magnetic circuit, which will attract a permanent magnet. By closed loop Magnetic core and permanent magnet will have magnetic field lines flowing through them.
An EMF is induced from the flowing magnetic flux in coils II, III, IV. The electrical potential from the IV coil is supplied to the base of the transistor VT1, creating a control signal. The EMF in coil III is designed to maintain the magnetic flux in the magnetic circuits. The emf in coil II provides power to the load.
The stumbling block in the practical implementation of such a free energy generator is the creation of an alternating magnetic flux. To do this, it is recommended to install two circuits with permanent magnets in the circuit, in which the power lines are in the opposite direction.
In addition to the above free energy generator using magnets, today there are a number of similar devices designed by Searle, Adams and other developers, the generation of which is based on the use of a constant magnetic field.
Followers of Nikola Tesla and their generators
The seeds sown by Tesla incredible inventions generated in the minds of applicants an unquenchable thirst to turn into reality fantastic ideas for creating a perpetual motion machine and send mechanical generators to the dusty shelf of history. The most famous inventors used the principles laid down by Nikola Tesla in their devices. Let's look at the most popular of them.
Lester Hendershot
Hendershot developed a theory about the possibility of using the Earth's magnetic field to generate electricity. Lester presented the first models back in the 1930s, but they were never in demand by his contemporaries. Structurally, the Hendershot generator consists of two counter-wound coils, two transformers, capacitors and a movable solenoid.
Rice. 3: general form Hendershot generator The operation of such a free energy generator is only possible if it is strictly oriented from north to south, so a compass must be used to set up the operation. The coils are wound on wooden bases with multidirectional winding to reduce the effect of mutual induction (when EMF is induced in them, EMF will not be induced in the opposite direction). In addition, the coils must be tuned by a resonant circuit.
John Bedini
Bedini introduced his free energy generator in 1984; a feature of the patented device was an energizer - a device with a constant rotating torque that does not lose speed. This effect was achieved by installing several permanent magnets on the disk, which, when interacting with an electromagnetic coil, create impulses in it and are repelled from the ferromagnetic base. Due to this, the free energy generator received a self-powering effect.
Bedini's later generators became known through a school experiment. The model turned out to be much simpler and did not represent anything grandiose, but it was able to perform the functions of a generator of free electricity for about 9 days without outside help.
Rice. 4: circuit diagram Bedini generator Look at Figure 4, here is a schematic diagram of the free energy generator of that same school project. It uses the following elements:
- a rotating disk with several permanent magnets (energizer);
- coil with a ferromagnetic base and two windings;
- battery (in this example it was replaced with a 9V battery);
- control unit consisting of a transistor (T), resistor (P) and diode (D);
- Current collection is organized from an additional coil that powers the LED, but power can also be supplied from the battery circuit.
With the start of rotation, the permanent magnets create magnetic excitation in the coil core, which induces an emf in the windings of the output coils. Due to the direction of the turns in the starting winding, current begins to flow, as shown in the figure below, through the starting winding, resistor and diode.
Rice. 5: start of operation of the Bedini generator When the magnet is located directly above the solenoid, the core is saturated and the stored energy becomes sufficient to open the transistor T. When the transistor opens, current begins to flow in the working winding, which recharges the battery.
Figure 6: Starting the charging winding At this stage, the energy becomes sufficient to magnetize the ferromagnetic core from the working winding, and it receives a pole of the same name with a magnet located above it. Thanks to the magnetic pole in the core, the magnet on the rotating wheel is repelled from this pole and accelerates the further movement of the energizer. As the movement accelerates, pulses appear in the windings more often, and the LED switches from flashing mode to constant glow mode.
Alas, such a free energy generator is not perpetual motion machine, in practice, he allowed the system to work tens of times longer than it could function on a single battery, but eventually it still stops.
Tariel Kapanadze
Kapanadze developed a model of his free energy generator in the 80s and 90s of the last century. Mechanical device based on the operation of an improved Tesla coil, as the author himself claimed, the compact generator could power consumers with a power of 5 kW. In the 2000s, Kapanadze's generator industrial scale they tried to build one with 100 kW in Turkey; according to its technical characteristics, it required only 2 kW for start-up and operation.
Rice. 7: schematic diagram of the Kapanadze generator The figure above shows a schematic diagram of a free energy generator, but the main parameters of the circuit remain a trade secret.
Practical circuits of free energy generators
Despite the large number existing schemes free energy generators, very few of them can boast real results, which could be tested and repeated at home.
Rice. 8: Tesla generator working diagram Figure 8 above shows a free energy generator circuit that you can replicate at home. This principle was outlined by Nikola Tesla; it uses a metal plate isolated from the ground and located on some hill. The plate is a receiver of electromagnetic oscillations in the atmosphere, this includes a fairly wide range of radiation (solar, radiomagnetic waves, static electricity from the movement of air masses, etc.)
The receiver is connected to one of the plates of the capacitor, and the second plate is grounded, which creates the required potential difference. The only stumbling block to its industrial implementation is the need to isolate the plate on a hill large area for feeding at least a private home.
Modern look and new developments
Despite widespread interest in creating a free energy generator, they are still unable to displace the classical method of generating electricity from the market. Developers of the past, who put forward bold theories about significantly reducing the cost of electricity, lacked the technical perfection of the equipment or the parameters of the elements could not provide the desired effect. And thanks scientific and technological progress humanity is receiving more and more new inventions that make the embodiment of a free energy generator already tangible. It should be noted that today free energy generators powered by the sun and wind have already been obtained and are actively being used.
But, at the same time, on the Internet you can find offers to purchase such devices, although most of them are dummies created with the aim of deceiving an ignorant person. And a small percentage of actually operating free energy generators, whether on resonant transformers, coils or permanent magnets, can only cope with powering low-power consumers; they cannot provide electricity, for example, to a private house or lighting in the yard. Free energy generators – promising direction, but their practical implementation has not yet been implemented.
For powering household devices and industrial equipment a source of electricity is required. It is possible to generate electric current in several ways. But the most promising and cost-effective today is the generation of current by electric machines. The easiest to manufacture, cheapest and most reliable in operation turned out to be an asynchronous generator, which generates the lion's share of the electricity we consume.
The use of electric machines of this type is dictated by their advantages. Asynchronous electric generators, in contrast, provide:
- higher degree of reliability;
- long service life;
- efficiency;
- minimal maintenance costs.
These and other properties of asynchronous generators are inherent in their design.
Design and principle of operation
The main working parts of an asynchronous generator are the rotor (moving part) and the stator (fixed part). In Figure 1, the rotor is located on the right and the stator on the left. Pay attention to the rotor design. There are no copper wire windings visible on it. In fact, windings exist, but they consist of aluminum rods short-circuited to rings located on both sides. In the photo, the rods are visible in the form of oblique lines.
The design of short-circuited windings forms a so-called “squirrel cage”. The space inside this cage is filled with steel plates. To be precise, aluminum rods are pressed into slots made in the rotor core.
Rice. 1. Rotor and stator of an asynchronous generator
An asynchronous machine, the structure of which is described above, is called a squirrel-cage generator. Anyone who is familiar with the design of an asynchronous electric motor has probably noticed the similarity in the structure of these two machines. In essence, they are no different, since the asynchronous generator and the squirrel-cage electric motor are almost identical, with the exception of additional excitation capacitors used in generator mode.
The rotor is located on a shaft, which sits on bearings clamped on both sides by covers. The entire structure is protected by a metal casing. Generators of medium and high power require cooling, so a fan is additionally installed on the shaft, and the housing itself is made ribbed (see Fig. 2).
Rice. 2. Asynchronous generator assembly Operating principle
By definition, a generator is a device that converts mechanical energy into electrical current. It does not matter what energy is used to rotate the rotor: wind, potential energy of water, or internal energy converted by a turbine or internal combustion engine into mechanical energy.
As a result of rotor rotation, magnetic field lines formed by the residual magnetization of the steel plates cross the stator windings. An EMF is generated in the coils, which, when active loads are connected, leads to the formation of current in their circuits.
In this case, it is important that the synchronous speed of rotation of the shaft is slightly (about 2 - 10%) higher than the synchronous frequency of alternating current (set by the number of stator poles). In other words, it is necessary to ensure asynchrony (mismatch) of the rotation speed by the amount of rotor slip.
It should be noted that the current obtained in this way will be small. To increase the output power it is necessary to increase the magnetic induction. Are seeking increasing efficiency devices by connecting capacitors to the terminals of the stator coils.
Figure 3 shows a diagram of a capacitor-excited asynchronous welding alternator (left side of the diagram). Please note that the field capacitors are connected in a delta configuration. The right side of the figure is the actual diagram of the inverter welding machine itself.
Rice. 3. Scheme of a welding asynchronous generator There are other, more complex excitation schemes, for example, using inductors and a bank of capacitors. An example of such a circuit is shown in Figure 4.
Figure 4. Device diagram with inductors Difference from synchronous generator
The main difference between a synchronous alternator and an asynchronous generator is the rotor design. In a synchronous machine, the rotor consists of wire windings. To create magnetic induction, an autonomous power source is used (often an additional low-power DC generator located on the same axis as the rotor).
The advantage of a synchronous generator is that it generates a higher quality current and is easily synchronized with other alternators of a similar type. However, synchronous alternators are more sensitive to overloads and short circuits. They are more expensive than their asynchronous counterparts and more demanding to maintain - it is necessary to monitor the condition of the brushes.
The harmonic coefficient or clearing factor of asynchronous generators is lower than that of synchronous alternators. That is, they generate almost pure electricity. The following operate more stable at such currents:
- adjustable chargers;
- modern television receivers.
Asynchronous generators provide reliable starting of electric motors that require high starting currents. In this indicator, they are actually not inferior to synchronous machines. They have fewer reactive loads, which has a positive effect on thermal conditions, since less energy is spent on reactive power. An asynchronous alternator has better output frequency stability at different speeds rotor rotation.
Classification
Short-circuit type generators are most widespread due to the simplicity of their design. However, there are other types of asynchronous machines: alternators with a wound rotor and devices using permanent magnets that form an excitation circuit.
For comparison, Figure 5 shows two types of generators: on the left on the base, and on the right - an asynchronous machine based on an IM with a wound rotor. Even a quick glance at the schematic images reveals the complex design of the wound rotor. The presence of slip rings (4) and a brush holder mechanism (5) attracts attention. The number 3 indicates the grooves for the wire winding, to which current must be supplied to excite it.
Rice. 5. Types of asynchronous generators The presence of field windings in the rotor of an asynchronous generator improves the quality of the generated electric current, however, such advantages as simplicity and reliability are lost. Therefore, such devices are used as a source of autonomous power only in those areas where it is difficult to do without them. Permanent magnets in rotors are used mainly for the production of low-power generators.
Application area
The most common use of generator sets with a squirrel cage rotor. They are inexpensive and require virtually no maintenance. Devices equipped with starting capacitors have decent efficiency indicators.
Asynchronous alternators are often used as stand-alone or backup source nutrition. They work with them, they are used for powerful mobile and.
Alternators with three-phase windings reliably start a three-phase electric motor, therefore they are often used in industrial power plants. They can also power equipment in single-phase networks. The two-phase mode allows you to save fuel on the internal combustion engine, since the unused windings are in idle mode.
The scope of application is quite extensive:
- transport industry;
- Agriculture;
- household sphere;
- medical institutions;
Asynchronous alternators are convenient for the construction of local wind and hydraulic power plants.
DIY asynchronous generator
Let’s make a reservation right away: we are not talking about making a generator from scratch, but about converting an asynchronous motor into an alternator. Some craftsmen use a ready-made stator from a motor and experiment with the rotor. The idea is to use neodymium magnets to make the rotor poles. A workpiece with glued magnets might look something like this (see Fig. 6):
Rice. 6. Blank with glued magnets You glue magnets onto a specially machined workpiece mounted on the electric motor shaft, observing their polarity and shift angle. This will require at least 128 magnets.
The finished structure must be adjusted to the stator and at the same time ensure a minimum gap between the teeth and the magnetic poles of the manufactured rotor. Since the magnets are flat, you will have to grind or sharpen them, while constantly cooling the structure, since neodymium loses its magnetic properties when high temperature. If you do everything correctly, the generator will work.
The problem is that it is very difficult to make an ideal rotor in artisanal conditions. But if you have lathe and you are ready to spend several weeks on adjustments and modifications - you can experiment.
I offer more practical option– turning an asynchronous motor into a generator (see video below). To do this, you will need an electric motor with suitable power and an acceptable rotor speed. The engine power must be at least 50% higher than the required alternator power. If you have such an electric motor at your disposal, start processing. Otherwise, it is better to buy a ready-made generator.
For recycling you will need 3 capacitors of the KBG-MN, MBGO, MBGT brands (you can take other brands, but not electrolytic ones). Select capacitors for a voltage of at least 600 V (for a three-phase motor). The reactive power of the generator Q is related to the capacitance of the capacitor by the following dependence: Q = 0.314·U 2 ·C·10 -6.
As the load increases, the reactive power increases, which means that in order to maintain a stable voltage U it is necessary to increase the capacitance of the capacitors, adding new capacitances through switching.
Video: making an asynchronous generator from a single-phase motor - Part 1
Part 2
In practice, the average value is usually chosen, assuming that the load will not be maximum.
Having selected the parameters of the capacitors, connect them to the terminals of the stator windings as shown in the diagram (Fig. 7). The generator is ready.
Rice. 7. Capacitor connection diagram An asynchronous generator does not require special care. Its maintenance consists of monitoring the condition of the bearings. At nominal modes, the device can operate for years without operator intervention.
The weak link is the capacitors. They can fail, especially when their denominations are incorrectly selected.
The generator heats up during operation. If you often connect increased loads, monitor the temperature of the device or take care of additional cooling.
