Chainsaw Speed ​​Adjustment by Laser Tachometer

Do-it-yourself generator from an asynchronous motor. How to convert an induction motor into a generator

Making a generator out of an asynchronous motor with your own hands is not difficult, but you will have to try and spend some money on the purchase of components. But for the work you need to know some subtleties. In particular, the operating principles of an asynchronous AC motor, to study the basic elements of its design. The main thing in generator sets is the movement of the magnetic field. It can be provided by rotating the armature using an internal combustion engine or a wind turbine. It is also possible to use alternative sources. the strength of water, steam, etc.

Induction motor design

You can select just a few elements:

  1. Stator with a winding.
  2. Front and rear covers with bearings installed.
  3. Squirrel cage rotor.
  4. Contacts for connecting to the electrical network.

If you think about it, it may seem that it is very simple to remake the engine into a generator, a photo of which you can examine in detail. But if you look more carefully, it turns out that not everything is so simple, there are plenty of pitfalls.

The stator consists of many metal plates pressed tightly to each other. They are also varnished, in some designs, to give strength, all plates are welded to each other. A wire is wound around the stator, it fits snugly to the core and is isolated from it with cardboard inserts. Bearings are located in the covers, with their help not only the rotor is rotated more easily, but also its centering.

Engine operating principle

The essence of the whole process is that a magnetic field is formed around the stator winding. It is powerful enough, but lacks the main component. the movement. The field is static, motionless, and the main condition in generator sets is rotation, a change in the direction of the lines of force. In the case of the engine, everything is quite simple. there is a rotor, which is made of metal. Inside are several turns of a very thick cable. over, all turns are closed, interconnected.

It turns out the principle of a simple transformer. In short-circuited turns, an EMF is induced, which creates an alternating magnetic field in the surrounding space. It turns out that now everything is there in order for the movement to appear. Under the influence of forces, the rotor of the electric motor rotates. This type of machine has good characteristics, and the design is simple and reliable, there is nothing to break. For this reason, induction motors are widely used in industry. than 95% of all motors in factories are asynchronous. Everyone can make a generator with their own hands, the circuit of which is not very complicated, with minimal knowledge.

Connection to a single-phase network

The true problem is connecting a three-phase electric motor to one. The principle of the generator is slightly different, but to understand it you need to consider the process of the motor. It is necessary to use a tank that will allow you to make a phase shift in the right direction. over, there are several schemes used in practice. In some, the capacitor is used only at the time of startup, in others and during operation. The starting capacity is turned on for a short period of time, until the required speed is reached. It contacts through a switch parallel to one of the windings connected by a triangle circuit.

Such connection options have one significant drawback. a decrease in electric motor power. You can get from him as a maximum 50 percent return. Therefore, with a motor power of 1.5 kW, in the case of power from a single-phase network, you can only get half. 0.75 kW. This imposes certain inconveniences, since it is necessary to use more powerful electric motors.

How to get three phases from one

For more convenient use of electric induction motors, three-phase power is required. But not everyone can conduct such a network to their home, and there are also difficulties with electricity. Therefore, you have to get out, as it turns out. The easiest way to install a frequency converter. But its cost is high, not everyone is able to allocate such an amount for their own garage or workshop. Therefore, you have to use improvised means. You will need an induction motor, capacitor and autotransformer. As the latter, you can use a homemade device made from the core of an electric motor. You can even make a generator drawing to simplify the assembly work.

About 400 turns of wire are required to be wound on it. Its diameter is about 6 square meters. mm For accuracy, ten taps are required to make phase adjustments. You can even say that this is a self-made generator made of an asynchronous motor. Only its main function is transformation, phase shift. One winding is connected to the phase, a capacitor is connected between the other two. The second winding is connected to zero, the third is connected there, only through an autotransformer. Its average output is one phase, the other two are the conclusions of the outlet.

What to consider for conversion to a generator

To make a wind generator out of an (asynchronous!) Motor, you need to consider one main feature. Namely, to create a magnetic field that will make a movement. There are two ways to achieve this. The first is the installation of permanent magnets on the rotor. The second is to make the field winding at anchor. Both methods have both advantages and disadvantages.

You need to decide before starting work what type of current generator you need. If you need a constant, then you need to use diodes for rectification. This will provide light to a small house, as well as power almost any household equipment. Homemade current generators can even be driven by wind. It is only necessary to calculate the windings so that the output does not exceed the voltage. Although stabilization can be done by using the regulators used in automotive technology.

Permanent magnets or field winding?

As mentioned earlier, you can make an excitation winding or carry out the installation of permanent magnets. The disadvantage of the latter method is the high cost of magnets. And the minus of the first is the need to use a brush assembly to provide power. He needs care and timely replacement. The reason is friction, which gradually eats up the surface of the graphite brush. Any car generator, the instructions of which are always attached, has just such a drawback.

To make the field winding, it is enough to change the design of the armature. It should be metal, a wire in varnish insulation must be wound on it. It will also be necessary to establish contacts on one edge of the rotor that are used for power supply. But the plus is that it is possible to stabilize the voltage at the output of the generator. It will be easier to make anchors in the anchor for mounting niode magnets. They create a very strong field, which is enough to generate large values ​​of voltage and current.

How many phases do you need to output?

The easiest way, of course, is to make a generator, the photo of which is shown if the output should be only one phase. But there is a snag. not every design allows this. A home-made generator from an induction motor of this type can be made if all the windings are brought out and not interconnected. Many models of motors have only three outputs, the rest are already connected internally, so to implement the idea you need to completely disassemble it and bring the necessary wires out.

Then they are connected in series and a single-phase voltage can be obtained at the output. But if you need a three-phase, it does not cost to do anything, modernization of the windings is not required. But you still need to take into account the features. It is necessary that a generator made of an asynchronous motor, made by oneself, have a connection of windings according to the star scheme. Here is a slight difference from the option when the machine works as source of movement. Efficient power generation is only possible when the star is turned on.

How to rectify the current?

But if there is a need for direct current, you will need knowledge of circuitry. Need 12 or 24 volts voltage? Nothing is simpler; automotive electronics come to the rescue. But only if the field winding is used as a magnetic field generator. When using permanent magnets, the stabilization procedure is complicated.

The rectifier option is selected based on the number of phases at the generator output. If there is one, then a bridge circuit is sufficient, or even on a single diode (a half-wave rectifier). If there are three phases at the output, then there will be a need to use six semiconductors for rectification. Also, three pieces (one for each phase). to protect against reverse voltage.

How to make one phase out of three

This action does not need to be carried out, since it is simply meaningless. If the generator generates a three-phase alternating voltage, then to power consumers (TV, incandescent lamps, refrigerators, etc.), it is necessary to use only one output. The second is the common, connection point of the windings. As mentioned earlier, it is required to connect them in a star pattern.

Therefore, you have the opportunity to connect consumers to one of the phases. The question is, does it make sense, is it rational to do so? If it is necessary to provide the house exclusively with light, you do not plan to connect any consumers, then it is more reasonable to use low-power LED lamps. They consume a small amount of electricity, so the current generator, which delivers stably 12 Volts, is able to provide the house not only with light. You can easily turn on household appliances that require just such voltage to work.

Wire winding rules

Such information is not always needed, since, in order to simplify the design, the stator winding that is already available is used. But she does not always satisfy the conditions that confront you. For example, if you are constructing a wind generator from a (asynchronous) motor, it is not possible to obtain a minimum number of rotor revolutions. Therefore, the output voltage will be small and insufficient for the operation of household appliances. Therefore, there is a need for small alterations.

The winding must be carried out with a thicker wire in order to obtain a higher value of the output current. To do this, get rid of the old wire. The winding is close to the cardboard frame. When it is carried out, it is required to apply a layer of varnish, soak the wire with it. Just do not forget to dry thoroughly before using the device. To do this, install a 25 or 40 W incandescent lamp in the middle of the stator and leave it for 1-2 days. Do not leave unattended only.

Experimental determination of the required number of turns

To determine how many turns you need for normal operation of the generator, you will need to use many formulas. But you need to know the cross section of the core, the material from which it is made. But this is often simply impossible to determine. Therefore, you have to do experiments. Depending on whether one or three phases you need, the algorithm of the experiment changes. A home-made generator from an induction motor can be made by various methods.

If you plan to make one phase at the output, then reel 10-20 turns of wire evenly around the entire core. Assemble the entire structure and connect to the drive that you will use in the future. Measure the output voltage, divide by the number of turns that are wound. And you get the voltage taken from one turn. To calculate the length of the winding, you need to apply a simple calculation. divide the voltage (necessary) by the obtained value. The calculation of a three-phase generator is carried out similarly.


Making a generator from an asynchronous motor with your own hands is not difficult. The most important thing is to decide which drive you plan to use. If this is a regular gasoline engine, then no problems will arise. Great difficulties will arise if you use a windmill as a drive. The reason is the engine speed, as well as the output voltage, are directly dependent on the strength of the wind, its speed. Therefore, such generators must be calculated in such a way that even at minimum speed, a rated voltage is generated. But at the output it is desirable to have no more than 12 volts. This will prove to be a simpler solution.

Home-made generator from an asynchronous electric motor

In an effort to obtain autonomous sources of electricity, experts have found a way to remake a three-phase asynchronous AC motor into a generator with their own hands. This method has several advantages and individual disadvantages.

Appearance of an induction motor

The section shows the main elements:

  1. cast iron housing with radiator fins for efficient cooling;
  2. the case of a squirrel-cage rotor with fishing line shear magnetic field relative to its axis;
  3. switching contact group in the box (boron), for switching stator windings into star or delta circuits and connecting power wires;
  4. dense strings of copper wires of the stator winding;
  5. steel rotor shaft with groove for securing the pulley with a wedge-shaped key.

A detailed disassembly of the induction motor with an indication of all the details is shown in the figure below.

Detailed disassembly of the induction motor

Advantages of generators converted from asynchronous motors:

  1. ease of assembly of the circuit, the ability not to disassemble the electric motor, not to rewind the windings;
  2. the possibility of rotation of the electric current generator by a wind or hydraulic turbine;
  3. a generator from an induction motor is widely used in motor-generator systems to convert a single-phase 220V AC network into a three-phase network with a voltage of 380V.
  4. the possibility of using a generator, in the field spinning it from internal combustion engines.

As a drawback, it is possible to note the complexity of calculating the capacitance of capacitors connected to the windings, in fact, this is done experimentally.

Therefore, it is difficult to achieve the maximum power of such a generator, there are difficulties with the power supply of electrical installations, which are of great importance inrush current, on circular saws with three-phase AC motors, concrete mixers and other electrical installations.

The principle of operation of the generator

The operation of such a generator is based on the principle of reversibility: "any electrical installation that converts electrical energy into mechanical energy can do the opposite process." The principle of operation of the generators is used, the rotation of the rotor causes EMF and the appearance of an electric current in the stator windings.

Based on this theory, it is obvious that an induction motor can be converted into an electric generator. In order to consciously carry out the reconstruction, it is necessary to understand how the generation process occurs and what is required for this. All motors driven by AC power are considered asynchronous. The stator field moves slightly ahead of the magnetic field of the rotor, pulling it along in the direction of rotation.

In order to obtain the reverse process, generation, the rotor field must be ahead of the motion of the stator magnetic field, in the ideal case, rotate in the opposite direction. This is achieved by including a large capacitor in the power supply network, and groups of capacitors are used to increase the capacity. The capacitor unit is charged, accumulating magnetic energy (an element of the reactive component of alternating current). The capacitor charge is in phase opposite to the current source of the electric motor, so the rotation of the rotor begins to slow down, the stator winding generates a current.

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This principle of operation is used practically in electric locomotives, trams, if necessary, smooth braking. By the same principle, some “Kulibins” slow down the rotation of the disk of electric meters, trying to reduce the cost of electricity.


How to practically convert an induction motor into a generator with your own hands?

To connect the capacitors, it is necessary to unscrew the upper boron cover (box), where the contact group is located, switching the contacts of the stator windings and the power wires of the induction motor are connected.

Open boron with contact group

Stator windings can be connected in a "Star" or "Triangle" circuit.

Star and Triangle switching schemes

On the nameplate or in the product passport the possible connection diagrams and motor parameters for various connections are shown. It is indicated:

  • maximum currents;
  • supply voltage;
  • power consumption;
  • number of revolutions per minute;
  • Efficiency and other parameters.

Engine parameters indicated on the nameplate

In a three-phase generator made of an asynchronous electric motor, which they do with their own hands, the capacitors are connected in the same way as a "Triangle" or "Star".

The inclusion option with the "Star" provides a starting process for generating current at lower speeds than when connecting the circuit to the "Triangle". In this case, the voltage at the output of the generator will be slightly lower. Connection according to the "Triangle" scheme provides a slight increase in the output voltage, but requires a higher speed when starting the generator. In a single-phase asynchronous electric motor, one phase-shifting capacitor is connected.

The connection diagram of the capacitors on the generator in the "Triangle"

The capacitors of the KBG-MN model are used, or other brands of at least 400 V non-polar, bipolar electrolytic models are not suitable in this case.

What does the KBG-MN brand capacitor look like

Since in everyday conditions it is practically impossible to calculate the required capacitance of the capacitors for the engine used, a table was compiled experimentally.

Calculation of capacitance for the used engine

In synchronous generators, the generation process is excited on the armature windings from the current source. 90% of induction motors have squirrel-cage rotors, without winding, the excitation is created by the residual static charge in the rotor. It is enough to create an EMF at the initial stage of rotation, which induces current, and recharges the capacitors through the stator windings. Further recharging is already coming from the generated current, the generation process will be continuous while the rotor rotates.

It is recommended to install the load connecting machine to the generator, sockets and capacitors in a separate closed panel. Connect the connecting wires from the boron generator to the shield in a separate insulated cable.

Even when the generator is not working, it is necessary to avoid touching the terminals of the capacitors of the sockets. The charge accumulated by the capacitor remains for a long time and can cause an electric shock. Ground the chassis of all units, motor, generator, control panel.

Installation of the motor-generator system

When installing a generator with a do-it-yourself motor, it should be borne in mind that the indicated number of nominal revolutions of the used asynchronous idle motor is greater.

Belt drive motor generator circuit

On an engine of 900 rpm, when idling, it will be 1230 rpm, in order to get sufficient power at the output of the generator converted from this engine, you need to have 10% more idle speed:

1230 10% = 1353 rpm.

Belt drive is calculated by the formula:

Vg. the required rotation speed of the generator 1353 rpm;

Vm. motor rotation speed of 1200 rpm;

Dm. pulley diameter on the motor 15 cm;

Dg. pulley diameter on the generator.

Having a 1200 rpm motor where the pulley is Ø 15 cm, it remains to calculate only Dg. the pulley diameter on the generator.

Dg = Vm x Dm / Vg = 1200 rpm x 15cm / 1353 rpm = 13.3 cm.

Neodymium Magnet Generator

How to make a generator from an induction motor?

This homemade generator eliminates the use of capacitor units. The source of the magnetic field, which induces the EMF and creates a current in the stator winding, is built on permanent niode magnets. In order to do this yourself, you must sequentially perform the following steps:

  • Remove the front and rear covers of the induction motor.
  • Remove the rotor from the stator.

What does an induction motor rotor look like?

  • The rotor is pumped, the upper layer is removed 2 mm more than the thickness of the magnets. In domestic conditions, it is not always possible to make a bore of the rotor with your own hands, in the absence of turning equipment and skills. You need to turn to specialists in turning workshops.
  • A template is prepared on a sheet of plain paper for placing round magnets, Ø 10-20 mm, thickness up to 10 mm, with an attractive force of 5-9 kg, per sq / cm, the size depends on the size of the rotor. The template is glued to the surface of the rotor, magnets are placed in strips at an angle of 15. 20 degrees relative to the axis of the rotor, 8 pieces in a strip. The figure below shows that on some rotors there are dark-light strips of displacement of the magnetic field lines relative to its axis.

Installing magnets on the rotor

  • The rotor with magnets is calculated so that four groups of strips are obtained, in a group of 5 strips, the distance between the groups is 2Ø of the magnet. Gaps in the group 0.5-1Ø of the magnet, this arrangement reduces the sticking force of the rotor to the stator, it must be rotated by two fingers;
  • The rotor on magnets, made according to the calculated template, is filled with epoxy resin. After it dries a little, the cylindrical part of the rotor is covered with a layer of fiberglass and again impregnated with epoxy resin. This eliminates the emergence of magnets during rotation of the rotor. The top layer on the magnets should not exceed the initial diameter of the rotor, which was before the groove. Otherwise, the rotor will not fall into place or during rotation will rub on the stator winding.
  • After drying, the rotor can be put in place and close the covers;
  • To test, the electric generator is necessary. to rotate the rotor with an electric drill, measuring the voltage at the output. The number of revolutions when the desired voltage is reached is measured by the tachometer.
  • Knowing the required number of revolutions of the generator, the belt drive is calculated according to the method described above.

An interesting application, when an electric generator based on an asynchronous electric motor, is used in the circuit of an electric motor-generator with self-feeding. When part of the power generated by the generator is supplied to an electric motor, which spins it. The remaining energy is spent on the payload. By implementing the principle of self-feeding, it is practically possible for a long time to provide the house with autonomous power supply.

Video. Generator from an induction motor.

For a wide range of electricity consumers, it makes no sense to buy powerful diesel power plants like TEKSAN TJ 303 DW5C with an output power of 303 kVA or 242 kW. Low-power gasoline generators are expensive, the best option is to make do-it-yourself wind generators or a self-feeding motor-generator device.

Using this information, you can assemble the generator yourself, with permanent magnets or capacitors. Such equipment is very useful in country houses, in the field, as an emergency power source, when there is no voltage in industrial networks. A full-fledged house with air conditioning, electric stoves and heating boilers, a powerful circular saw motor they will not pull. Temporarily provide electricity for household appliances of prime necessity can, lighting, refrigerator, TV and others that do not require large capacities.

DIY motor generator

Due to the non-standard method of generation, and the original design of the motor-generator, the modes of the generator and electric motor are combined in one process, and are inextricably linked.
As a result, when the load is connected, the interaction of the magnetic fields of the stator and rotor forms a torque that coincides in direction with the moment created by the external drive.

In other words, as the power consumed by the load of the generator increases, the rotor of the motor-generator starts to accelerate, and accordingly, the power consumed by the external drive decreases.

For a long time there have been rumors on the Internet that a generator with a Gram ring anchor was capable of generating more electrical energy than was expended by mechanical energy and this was due to the fact that there was no braking moment under load.

The results of the experiments that led to the invention of the motor generator.

For a long time there have been rumors on the Internet that a generator with a Gram ring anchor was capable of generating more electrical energy than was expended by mechanical energy and this was due to the fact that there was no braking moment under load. This information prompted us to conduct a series of experiments with a ring winding, the results of which we will show on this page. For experiments, 24 pcs., Independent windings with the same number of turns were wound on a toroidal core.

1) Initially, the weight of the windings were connected in series, the findings on the load are located diametrically. In the center of the winding was a permanent magnet with the possibility of rotation.

After the magnet was driven by the drive, the load was connected and the drive speed was measured with a laser tachometer. As one would expect, the speed of the drive motor began to fall. The more power the load consumed, the more the revs fell.

2) For a better understanding of the processes occurring in the winding, instead of a load, a direct current milliammeter was connected.
With a slow rotation of the magnet, one can observe what polarity and magnitude of the output signal is in a given position of the magnet.

It can be seen from the figures that when the poles of the magnet are opposite the terminals of the winding (Fig. 4; 8), the current in the winding is 0. When the magnet is in position, when the poles are in the center of the winding, we have the maximum current value (Fig. 2; 6).

3) At the next stage of the experiments, only one half of the winding was used. The magnet also rotated slowly, and the readings of the device were recorded.

The readings of the device completely coincided with the previous experiment (Fig. 1-8).

4) After that, an external drive was connected to the magnet and began to rotate it at maximum speed.

When connecting the load, the drive began to gain momentum!

In other words, during the interaction of the magnet poles and the poles formed in the winding with the magnetic circuit, when passing through the current winding, a torque appeared along the direction of the torque created by the drive motor.

Figure 1, there is strong braking of the drive when the load is connected. Figure 2, when the load is connected, the drive starts to accelerate.

5) In order to understand what is happening, we decided to create a map of the magnetic poles that appear in the windings when current passes through them. For this, a series of experiments was carried out. The windings were connected in different versions, and DC pulses were applied to the ends of the windings. At the same time, a permanent magnet was fixed on the spring, and in turn was located next to each of the 24 windings.

According to the reaction of the magnet (it was repelled or attracted), a map of the manifesting poles was compiled.

From the figures it is seen how the magnetic poles appeared in the windings, with different switching on (yellow rectangles in the figures, this is the neutral zone of the magnetic field).

When changing the polarity of the pulse, the poles, as expected, were reversed, so the different options for turning on the windings are drawn with the same power polarity.

6) Pa at a glance, the results in Figures 1 and 5 are identical.

In a more detailed analysis, it became clear that the distribution of the poles around the circumference and the "size" of the neutral zone are quite different. The force with which the magnet was attracted or repelled from the windings and the magnetic circuit is shown by the gradient filling of the poles.

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7) When comparing the data of the experiments described in paragraphs 1 and 4, in addition to the cardinal difference in the response of the drive to the load connection, and a significant difference in the "parameters" of the magnetic poles, other differences were revealed. During both experiments, a voltmeter was turned on in parallel with the load, and an ammeter was turned on in series with the load. If the readings of the instruments from the first experiment (point 1) are taken as 1, then in the second experiment (point 4), the voltmeter reading was also equal to 1. According to the ammeter reading, it was 0.005 from the results of the first experiment.

8) Based on the foregoing in the previous paragraph, it is logical to assume that if in the unused part of the magnetic circuit, to make a non-magnetic (air) gap, then the current strength in the winding should increase.

After the air gap was made, the magnet was again connected to the drive motor, and spun at maximum speed. The current strength actually increased several times, and began to be approximately 0.5 of the results of the experiment under paragraph 1,
but at the same time there was a braking moment on the drive.
9) By the method described in paragraph 5, a map of the poles of this design was compiled.

10) Compare the two options

It is not difficult to assume that if you increase the air gap in the magnetic circuit, the geometrical arrangement of the magnetic poles in Figure 2 should approach that of Figure 1. And this, in turn, should lead to the acceleration effect of the drive, which is described in paragraph 4 (when connecting load, instead of braking, an additional moment is created to the drive torque).

11) After the gap in the magnetic circuit was increased to a maximum (to the edges of the winding), when the load was connected instead of braking, the drive again began to gain momentum.

In this case, the map of the poles of the winding with the magnetic circuit looks like this:

Based on the proposed principle of electricity generation, it is possible to design alternators, which, when the electric power in the load increases, do not require increasing the mechanical power of the drive.

The principle of operation of the Generator Motor.

According to the phenomenon of electromagnetic induction, when the magnetic flux passing through a closed circuit changes, an EMF appears in the circuit.

According to the Lenz rule: Induction current arising in a closed conducting circuit has such a direction that the magnetic field created by it counteracts the change in magnetic flux that caused this current. In this case, it does not matter how the magnetic flux moves in relation to the contour (Fig. 1-3).

The method of exciting the EMF in our motor-generator is similar to Figure 3. It allows you to use the Lenz rule to increase the torque on the rotor (inductor).

1) Stator winding
2) Stator magnetic circuit
3) Inductor (rotor)
4) Load
5) Direction of rotation of the rotor
6) Central line of the magnetic field of the poles of the inductor

When you turn on the external drive, the rotor (inductor) begins to rotate. When the beginning of the winding is crossed by a magnetic flux of one of the poles of the inductor, an EMF is induced in the winding.

When the load is connected, the current begins to flow in the winding and the poles of the magnetic field that has arisen in the windings according to the rule of E. X. Lenz are aimed at meeting the magnetic flux that excited them.
Since the winding with the core is located along an arc of a circle, the magnetic field of the rotor moves along the turns (arc of a circle) of the winding.

At the same time, at the beginning of the winding, according to the Lenz rule, a pole appears that is identical with the pole of the inductor, and at the other end it is opposite. Since the poles of the same name are repelled, and the opposite ones are attracted, the inductor tends to take a position that corresponds to the action of these forces, which creates an additional moment directed along the rotation of the rotor. The maximum magnetic induction in the winding is achieved at the moment when the central line of the pole of the inductor is opposite the middle of the winding. With further movement of the inductor, the magnetic induction of the winding decreases, and at the moment the center line of the pole of the inductor leaves the winding, it is zero. At the same moment, the beginning of the winding begins to cross the magnetic field of the second pole of the inductor, and according to the rules described above, the edge of the winding from which the first pole begins to move away begins to push it away with increasing force.

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1) Zero point, the poles of the inductor (rotor) are symmetrically directed to different edges of the winding in the winding EMF = 0.
2) The central fishing line of the north pole of the magnet (rotor) crossed the beginning of the winding, EMF appeared in the winding, and accordingly the magnetic pole appeared that was the same with the pole of the pathogen (rotor).
3) The rotor pole is located in the center of the winding, and the maximum EMF value in the winding.
4) The pole approaches the end of the winding and the EMF is reduced to a minimum.
5) The next zero point.
6) The central line of the south pole enters the winding and the cycle repeats (7; 8; 1).


From the CD-rom parsing, a number of brushless DC motors have accumulated (these are the ones that spin the disc). And they don’t seem to take up much space, but they often catch my eye. Finally I decided that I had to somehow decide on them.

So, this is a brushless DC motor, the position of the rotor in it is monitored by three Hall sensors, controlled by a driver chip BA6849FP (speed adjustment). In theory, everything is simple, but in practice, impressions can go off scale from just viewing the scarf on which the engine itself is installed.

Therefore, I did not delve into the purpose of the numerous cable conclusions, but simply took and halved the engine, and saw its stator. However, a full review of the circuit board was still unattainable. Realizing that there was no need for sacrifice, I unsoldered the wires (3 pieces) coming from the stator windings to the board, and then folded it up. broke the board in half with the metal mounting plate.

The freed stator flopped onto the table and, again, for educational purposes, was immediately unwound. Now I can report that the motor had three windings (phases) connected by the "star" method, but the option is possible when they can be connected by the "delta" method.

Assembly diagram

The electric motor certainly did not, but with it there was no shyness before the unknown, for now there was no unknown. In the photo, the conductors form windings and end with conclusions. The connections of the windings are different, but the electrical essence does not undergo large changes. The relatively thick wires of the stator windings suggested that it is possible to get a good current from this engine, if it is used as a generator, and even if it produces a few volts of voltage, then perhaps "happiness"!

I stopped here on such a scheme for removing an electric motor from a motor, however, now it is already a generator that produces electric current. This circuit was assembled and tested with the following ratings of electronic components: C1. 100 μF x 16 V, all six diodes 1N5817.

It would be interesting to try out such a scheme, but so far "your hands have not reached." As a more perfect option. put on the output stabilizer.

For further actions, another electric motor was taken and brought into proper condition for connection and mounting. Gears (gear pair) with a gear ratio of 1: 5 from the Chinese lantern. "bug".

Everything was mounted on a suitable foundation. Important in this operation is to correctly “take” the center-to-center distance of the gears and set their rotation axes in a single spatial plane.

The circuit is assembled, the newly turned generator is ready for the test.

With intensive, but without masochism, rotation of the large gear wheel with the fingers, the voltage easily reaches 1.7 volts (no load).

When connecting a load, 2.5 V and 150 mA light bulbs, the current reaches 120 mA. A light bulb flashes to the floor.

Video. work under load

I will take the liberty of declaring that even this particular engine can be used as a wind generator capable of generating enough electric current to charge one AAA battery with a voltage of 1.2 V and a capacity of up to 1000 mA inclusive. Please pay attention to the photo that shows the installation of gears on the base. On the right side of the large gear wheel and “ask for” the installation of another motor. The kinematic scheme will be as follows: one drive wheel rotates two followers. The possibilities are doubled, it becomes real to assemble a boost converter and even charge mobile phone batteries. I dealt with issues of electricity production Babay.

Electrical Engineering Forum


Homemade generator. Do it yourself

Method 1

I found an article on the Internet on how to convert a car’s generator into a permanent magnet generator. Is it possible to use this principle and remake the generator with your own hands from an asynchronous electric motor? It is possible that there will be large energy losses, not the arrangement of the coils.

I have an asynchronous motor with a voltage of 110 volts, rpm. 1450, 2.2 amperes, single-phase. With the help of containers, I do not presume to make a home-made generator, since there will be big losses.

It is proposed to use simple engines according to this scheme.

If you change the engine or generator with round magnets from the speakers, do you need to install them in crabs? Crabs are two metal parts, anchored outside the field coils.

If you put magnets on the shaft, the shaft will bypass the magnetic lines of force. How then will the excitement be? The coil is also located on a metal shaft.

If you change the connection of the windings and make a parallel connection, accelerate to rpm above normal values, you get 70 volts. Where to get the mechanism for such revolutions? If you rewind it to reduce speed and lower power, then the power will drop too.

An asynchronous closed-rotor motor is iron, which is flooded with aluminum. You can take a home-made generator from a car with a voltage of 14 volts, a current of 80 amperes. This is not bad data. An engine with an alternating current collector from a vacuum cleaner or a washing machine can be used for a generator. Install magnetization on the stator, remove the DC voltage from the brushes. At the highest EMF, change the angle of the brushes. The coefficient of performance tends to zero. But, better than a synchronous type generator, not invented.

I decided to try a homemade generator. The single-phase asynchronous motor from the baby’s washer twisted with a drill. I connected a 4 microfarad capacitance to it, it turned out 5 volts 30 hertz and a current of 1.5 milliamperes for a short circuit.

Not every electric motor can be used as a generator in this way. There are motors with a steel rotor having a low degree of magnetization on the remainder.

You need to know the difference between electric energy conversion and energy generation. There are several ways to convert 1 phase to 3. One of them is mechanical energy. If the power station is disconnected from the outlet, then the entire conversion disappears.

Where the movement of the wire with increasing speed will come from, is clear. Where the magnetic field will be for obtaining the EMF in the wire is not clear.

It is easy to explain. Due to the mechanism of magnetism that remains, an EMF is formed in the anchor. There is a current in the stator winding, which is closed on the capacitance.

The current has arisen, which means that it gives amplification to the electromotive force on the coils of the rotor shaft. The current that appears gives an amplification of the electromotive force. The stator electric current forms an electromotive force much more. This goes to the establishment of equilibrium of the stator magnetic fluxes and the rotor, as well as additional losses.

The size of the capacitors is calculated so that the voltage at the terminals reaches the nominal value. If it is small, then reduce the capacity, then increase. There were doubts about the old engines, which supposedly are not excited. After accelerating the rotor of the motor or generator, you need to poke quickly in any phase with a small amount of volts. Everything will return to normal. Charge the capacitor to a voltage equal to half the capacity. Switching on is done with a three-pole switch. This applies to a 3-phase motor. Such a scheme is used for generators of passenger carriages, since they have a short-circuited rotor.

Method 2

A homemade generator can be done in a different way. The stator has a cunning design (has a special design solution), it is possible to adjust the output voltage. I made this type of generator with my own hands in construction. The engine took a power of 7 kW at 900 rpm. I connected the field winding according to the scheme of a 220 V triangle. I started it at 1600 rpm, the capacitors were 3 at 120 uF. They were switched on by a contactor with three poles. The generator acted as a three-phase rectifier. An electric drill with a 1000-watt collector was fed from this rectifier, and a 2200-watt 220 V circular saw and a 2000-watt angle grinder were used.

I had to make a soft start system, another resistor with a shorted phase after 3 seconds.

For motors with manifolds, this is wrong. If you double the rotational frequency, then the capacity will decrease.

The frequency will also increase. The tank circuit was switched off automatically, so as not to use a reactivity torus, not to consume fuel.

During operation, press the contactor stator. Three phases dismantled them out of use. The reason lies in the high clearance and increased dispersion of the pole field.

Special mechanisms with a double cage for a squirrel and slanting eyes for a squirrel. Still, I got 100 volts and a frequency of 30 hertz from the washing machine’s motor, the 15-watt lamp does not want to burn. Very weak power. It is necessary to take the motor stronger, or put more capacitors.

Under the cars, a generator with a squirrel-cage rotor is used. Its mechanism comes from the gearbox and the belt drive. Rotational speed 300 rpm. It is located as an additional load generator.

Method 3

You can design a homemade generator, a gasoline power station.

Instead of a generator, use a 3-phase asynchronous motor of 1.5 kW at 900 rpm. Italian electric motor, can be connected by a triangle and a star. First, I put the motor on the base with a DC motor, attached to the coupling. He began to turn the engine at 1100 rpm. A voltage of 250 volts appeared in phases. I connected a 1000-watt light bulb, the voltage immediately dropped to 150 volts. This is probably from phase imbalance. A separate load must be included for each phase. Three light bulbs of 300 watts will not be able to reduce the voltage to 200 volts, theoretically. You can put a capacitor more.

Engine revolutions must be done more, do not reduce under load, then the mains supply will be constant.

Significant power is needed, the auto-generator will not give such power. If you rewind a large KAMAZ, then 220 V will not come out of it, since the magnetic circuit will be oversaturated. It was designed at 24 volts.

Today I was going to try to connect the load through a 3-phase power supply (rectifier). In the garages, the lights were turned off, it did not work. In the city of power engineers systematically turn off the light, so you need to make a constant source of electricity. For electric welding, there is a hitch, hooked to the tractor. To connect an electric tool, you need a constant voltage source of 220 V. There was an idea to design a home-made generator with your own hands, and an inverter to it, but you can not work on batteries for a long time.

Recently turned on the electricity. I connected an induction motor from Italy. I put it with the chainsaw motor on the frame, twisted the shafts together, put the rubber coupling. The coils are connected by a star circuit, the capacitors are delta, 15 microfarads each. When I started the motors, the power output failed. I connected a capacitor charged to the phases, the voltage appeared. The engine gave out its power of 1.5 kW. At the same time, the supply voltage dropped to 240 volts, at idle it was 255 volts. The sander worked fine for him at 950 watts.

I tried to increase the engine speed, but the excitation does not work. After the capacitor contacts the phase, the voltage appears immediately. I will try to put another engine.

What designs of systems abroad are made for power plants? On 1-phase, it is clear that the rotor owns the winding, there is no phase imbalance, because it is one phase. In 3-phase there is a system that provides power adjustment when connecting motors with the highest load to it. You can also connect an inverter for welding.

On the weekend I wanted to make a home-made generator with my own hands with an asynchronous motor connected. A successful attempt to make a home-made generator turned out to be the connection of an old engine with a cast iron housing of 1 kW and 950 revolutions. The motor is energized normally, with a single capacity of 40 microfarads. And I installed three tanks and connected them with a star. This was enough to start the electric drill, an angle grinder. I wanted to get a voltage output in one phase. For this, I connected three diodes, a half-bridge. The fluorescent lamps burned out for lighting, and the bags in the garage burnt out. I will wind the transformer in three phases.

DIY asynchronous motor generator

The desire to develop an autonomous source for the production of electricity made it possible to build a generator from a conventional asynchronous motor. Development is distinguished by reliability and relative simplicity.

Types and description of asynchronous motor

There are two types of motors:

Application area

The device is used in various industries:

  1. Like a conventional engine for wind power plants.
  2. For your own independent catering apartment or house.
  3. Like small hydropower stations.
  4. As an alternative inverter type of generator (welding).
  5. To create an uninterrupted AC power system.

Advantages and disadvantages of the generator

The positive qualities of development include:

  1. Simple and quick assembly with the ability to avoid disassembling the motor and rewinding the winding.
  2. The ability to carry out the rotation of an electric current using a wind or hydraulic turbine.
  3. The use of the device in motor-generator systems to convert a single-phase network (220V) to a three-phase (380 V).
  4. The ability to use the development in places where there is no electricity, using an internal combustion engine for promotion.


  1. The difficulty of calculating the capacity of the condensate, which is connected to the windings.
  2. It is difficult to reach the maximum power mark that self-development is capable of.
Chainsaw Speed ​​Adjustment by Laser Tachometer

Homemade asynchronous generator

Principle of operation

The generator generates electrical energy, provided that the number of revolutions of the rotor is slightly higher than the synchronous speed. The simplest type produces about 1800 rpm, given that the level of its synchronous speed becomes 1500 revolutions.

Its principle of operation is based on the conversion of mechanical energy into electricity. It is possible to force the rotor to rotate and produce electricity using strong torque. Ideally, a constant idle that is able to maintain the same speed.

All types of motors operating on a constant current are called asynchronous. They have a magnetic field of the stator spinning rather than the field of the rotor, respectively directing it in the direction of its movement. To change the electric motor to a functioning generator, it will be necessary to increase the speed of movement of the rotor so that it does not follow the magnetic field of the stator, but begins to move in the opposite direction.

You can get a similar result by connecting the device to the mains, a capacitor with a large capacity, or a whole group of capacitors. They charge and store energy from magnetic fields. The capacitor phase has a charge that is opposite to the motor current source, due to which the rotor slows down, and the current production by the stator winding begins.

Generator circuit

The scheme is very simple and does not require special knowledge and skills. If you start development without connecting it to the network, rotation will begin and, after reaching the synchronous frequency, the stator winding will begin to generate electrical energy.

By attaching a special battery of several capacitors (C) to its terminals, it is possible to obtain a leading capacitive current, which will create magnetization. Capacitor capacitance must be above critical designation C, which depends on the size and characteristics of the generator.

In this situation, a self-starting process takes place, and a system with a symmetric three-phase voltage is mounted on the stator winding. The indicator of the generated current directly depends on the capacitance for the capacitors, as well as the characteristics of the machine.

The simplest scheme for starting an induction motor

Do it yourself

To convert an electric motor into a working generator, you need to use non-polar capacitor banks, so it is better not to use electrolytic capacitors.

In a three-phase motor, you can connect a capacitor according to the following schemes:

  • "Star". makes it possible to conduct generation at a lower number of revolutions, but with a lower output voltage;
  • "Triangle". comes into operation with a large number of revolutions, respectively, produces more voltage.
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You can create your own device from a single-phase motor, but provided that it is equipped with a short-circuit rotor. To start development, you should use a phase-shifting capacitor. A single-phase collector-type motor is not suitable for alteration.

Appearance of a simple wind generator using an asynchronous motor

Necessary tools

Creating your own generator is easy, the main thing is to have all the necessary elements:

  1. Asynchronous motor.
  2. A tachogenerator (a device for measuring current) or a tachometer.
  3. Capacitance under capacitors.
  4. Capacitor.
  5. Instruments.


  1. Since it will be necessary to reconfigure the generator in such a way that the rotation speed exceeds the engine speed, initially it is necessary to connect the engine to the mains and start it. Then, using the tachometer, determine the speed of its rotation.
  2. Having learned the speed, it is necessary to add another 10% to the designation obtained. For example, the technical indicator of the motor is 1000 rpm, then the generator should have about 1100 rpm (10000.1% = 100, 1000100 = 1100 rpm).
  3. You should choose a capacity for capacitors. To determine the size, use the data in the table.

Capacitor Table

Important! If the capacity is large, the generator will begin to heat up.

Select the appropriate capacitors that can provide the required speed of rotation. Be careful when installing.

Important! All capacitors must be insulated with a special coating.

The device is ready and can be used as source of electricity.

Important! A device with a squirrel-cage rotor generates a high voltage, so if a 220V rating is needed, a step-down transformer should be additionally installed.

Magnet Generator

The magnetic generator has several differences. For example, it does not need to install capacitor banks. The magnetic field that will create electricity in the stator winding is created due to niode magnets.

Features of creating a generator:

  1. It is necessary to unscrew both engine covers.
  2. It will be necessary to eliminate the rotor.
  3. The rotor must be pierced by removing the top layer of the desired thickness (magnet thickness 2mm). It is extremely difficult to independently perform this procedure without turning equipment, so you should contact a turning service.
  4. Make a template for round magnets on a piece of paper, Based on the parameters, the diameter is 10–20 mm, the thickness is about 10 mm, and the swearing force is about 5–9 kg per cm 2. The size should be selected depending on the dimensions of the rotor. Then attach the created template to the rotor and place the magnets with poles and at an angle of 15-20 0 to the axis of the rotor. The approximate number of magnets in one strip is about 8 pieces.
  5. You should get 4 groups of strips, each of 5 strips. Between groups, a distance of 2 diameters of the magnet should be maintained, and between the strips in the group, 0.5-1 diameter of the magnet. Due to this arrangement, the rotor will not stick to the stator.
  6. Having installed all the magnets, it is necessary to fill the rotor with a special epoxy resin. Once it dries, cover the cylindrical element with fiberglass and impregnate with resin again. Such fastening will allow the escape of magnets at the time of movement. Make sure that the diameter at the rotor is the same as before the groove, so that during installation it does not rub against the stator winding.
  7. Having dried the rotor, it can be installed in place and screw on both engine covers.
  8. To test. To start the generator, you need to turn the rotor using an electric drill, and at the output, measure the received current with a tachometer.

Remodel or not

To determine whether the operation of a self-made generator is effective, one should calculate how justified the efforts to transform the device are.

This is not to say that the device is very simple. The induction motor is not inferior in complexity to a synchronous generator. The only difference is the lack of an electric circuit to initiate the work, but it is replaced by a capacitor bank, which does not simplify the device.

The advantage of capacitors is that they do not require additional maintenance, and they receive energy from the magnetic field of the rotor or the generated electric current. From this we can say that the only plus from this development is the lack of need for maintenance.

Another positive quality is the effect of the clear factor. It consists in the absence of higher harmonics in the generated current, that is, the lower its indicator, the less energy is spent on heating, the magnetic field and other moments. For a three-phase electric motor, this figure is about 2%, while for synchronous machines it is at least 15%. Unfortunately, taking into account the indicator in everyday life when different types of electrical appliances are included in the network is unrealistic.

Other indicators and development properties are negative. He is not able to provide the rated industrial frequency of the voltage produced. Therefore, the device is used together with rectifier machines, as well as for charging the battery.

The generator is sensitive to the slightest drops in electricity. In industrial developments, a battery is used to excite, and in a home-made version, part of the energy goes to a capacitor bank. In the case when the load on the generator is above nominal, it does not have enough electricity to recharge, and it stops. In some cases, capacitive batteries are used that change their dynamic volume depending on the load.

Unfortunately, it is unrealistic to calculate, take into account and compensate for changes in current that occur by chance, so the device is characterized by unstable operation.

Blitz Tips

  1. The device is very dangerous, therefore it is not recommended to use a voltage of 380 V, unless in emergency.
  2. According to precautionary measures and safety measures it is necessary to establish additional grounding.
  3. Watch out for thermal development. He is not inherent to work at idle. To reduce the thermal effect, a capacitor should be well selected.
  4. Correctly calculate the power of the generated electrical voltage. For example, when only one phase functions in a three-phase generator, it means that power is 1/3 of the total, and if two phases work, 2/3, respectively.
  5. It is possible to indirectly control the frequency of unstable current. When the device is idling, the output voltage begins to increase, and exceeds the industrial (220 / 380V) by 4-6%.
  6. It is best to isolate development.
  7. Homemade invention should be equipped with a tachometer and voltmeter, to fix his work.
  8. It is advisable to provide special buttons to turn on and off the mechanism.
  9. The level of efficiency will be reduced by 30-50%, this phenomenon is inevitable.

How to make a generator from an induction motor?

An asynchronous or induction type generator is a special kind of device that uses alternating current and has the ability to reproduce electricity. The main feature is the performance of rather quick turns that the rotor makes, in terms of the speed of rotation of this element it is significantly superior to the synchronous variety.

One of the main advantages is the ability to use this device without significant circuit transformations or lengthy tuning.

A single-phase type of induction generator can be connected by supplying the necessary voltage to it, for this it will need to be connected to a power source. However, a number of models produce self-excitation; this ability allows them to function in a mode independent of any external sources.

This is accomplished by sequentially bringing the capacitors to working condition.

Asynchronous motor generator circuit

generator circuit based on an induction motor

In virtually any electric type machine designed as a generator, there are 2 different active windings, without which the device cannot function:

  1. Field winding, which is located on a special anchor.
  2. Stator winding, which is responsible for the formation of electric current, this process occurs inside it.

In order to visualize and more accurately understand all the processes that occur during the operation of the generator, the most optimal option would be to consider in more detail the scheme of its operation:

  1. Voltage, which is supplied from a battery or any other source creates a magnetic field in the anchor winding.
  2. Rotate device elements together with the magnetic field can be implemented in various ways, including manually.
  3. A magnetic field, rotating at a certain speed generates electromagnetic induction, due to which an electric current appears in the winding.
  4. The vast majority of schemes used today it does not have the ability to provide voltage anchor winding, this is due to the presence of a squirrel-cage rotor in the design. Therefore, regardless of the speed and time of rotation of the shaft, the supply terminals of the device will still be de-energized.

When remaking the engine into a generator, the independent creation of a moving magnetic field is one of the basic and mandatory conditions.

Generator device

Before you take any action to remake the induction motor in the generator, you need to understand the device of this machine, which is as follows:

  1. Stator, which is equipped with a network winding with 3 phases, placed on its working surface.
  2. Winding It is organized in such a way that it resembles a star in its shape: 3 initial elements are connected to each other, and 3 opposite sides are connected to slip rings, which do not have any common ground between them.
  3. Contact rings have reliable fasteners to the rotor shaft.
  4. In construction there are special brushes that do not make any independent movements, but contribute to the inclusion of a rheostat with three phases. This allows you to change the resistance parameters of the winding located on the rotor.
  5. Often, in the internal device there is such an element as an automatic short circuit, necessary in order to short-circuit the winding and stop the rheostat, which is in working condition.
  6. Another additional element of the device generator may be a special device that spreads the brushes and slip rings at the moment when they pass the stage of closure. Such a measure contributes to a significant reduction in friction losses.

Making a generator out of an engine

In fact, any asynchronous electric motor can be remade with its own hands into a device that functions as a generator, which can then be used in everyday life. For this purpose, even an engine taken from an old-style washing machine or any other household equipment may be suitable.

In order for this process to be successfully implemented, it is recommended to adhere to the following algorithm of actions:

  1. Remove engine core layer, thanks to which a depression will be formed in its structure. This can be done on a lathe, it is recommended to remove 2 mm. around the core and make additional holes with a depth of about 5 mm.
  2. Take off dimensions from the resulting rotor, and then from the tin material to make a template in the form of a strip that will correspond to the dimensions of the device.
  3. Install in the resulting free space neodymium magnets, which must be purchased in advance. Each pole will require at least 8 magnetic elements.
  4. Magnet fixing can be carried out using universal superglue, but it must be borne in mind that when approaching the surface of the rotor they will change their position, so they must be firmly held by hands until each element adheres. It is further recommended that safety glasses be used during this process to avoid splashing glue into the eyes.
  5. Rotor wrap plain paper and scotch tape, which will be required to fix it.
  6. The end part of the rotor to fill with plasticine, which will ensure the sealing of the device.
  7. After committed actions it is necessary to process free cavities between the magnetic elements. To do this, the remaining space between the magnets must be filled with epoxy. It will be most convenient to cut a special hole in the shell, transform it into a neck and seal the borders with plasticine. Resin can be poured inside.
  8. Wait until it solidifies. filled resin, after which the protective paper cover can be removed.
  9. Rotor must be locked with a machine or vice so that it can be processed, which consists in grinding the surface. For these purposes, you can use sandpaper with an average grain size parameter.
  10. Determine state and the purpose of the wires leaving the engine. Two should lead to a working winding, the rest can be cut so as not to get confused in the future.
  11. Sometimes the rotation process is pretty bad, most often the cause is old worn and taut bearings, in which case they can be replaced with new ones.
  12. Generator rectifier can be assembled from special silicon diodes that are designed specifically for these purposes. Also, you will need a controller to charge, virtually all modern models are suitable.

After all these actions are completed, the process can be considered completed, the induction motor was converted into a generator of the same type.

Evaluation of the level of effectiveness. is it profitable?

Generation of electric current by an electric motor is quite real and realizable in practice, the main question is how profitable is this?

The comparison is carried out primarily with a synchronous version of a similar device, in which there is no electric excitation circuit, but despite this fact, its device and design are not simpler.

This is due to the presence of a capacitor bank, which is an extremely technically complex element that is not available in an asynchronous generator.

The main advantage of an asynchronous device is that the available capacitors do not require any maintenance, since all the energy is transferred from the magnetic field of the rotor and the current that is generated during the operation of the generator.

The electric current created during operation does not actually have higher harmonics, which is another significant advantage.

Asynchronous devices do not have other advantages besides the above, but they have a number of significant drawbacks:

  1. During their operation there is no possibility to ensure the rated industrial parameters of the electric current generated by the generator.
  2. High sensitivity even to the smallest differences in workload parameters.
  3. If the permissible generator loads are exceeded, there will be a shortage of electricity, after which recharging will become impossible and the generation process will be stopped. To eliminate this drawback, often use batteries with significant capacity, which have the ability to change their volume depending on the magnitude of the loads.

The electric current generated by an asynchronous generator is subject to frequent changes, the nature of which is unknown, it is random in nature and can not be explained by scientific arguments.

The impossibility of accounting and appropriate compensation for such changes is explained by the fact that such devices have not gained popularity and are not widely used in the most serious industries or domestic affairs.

The functioning of an induction motor as a generator

In accordance with the principles by which all similar machines operate, the operation of an induction motor after conversion to a generator occurs as follows:

  1. After connecting the capacitors to the terminals, on the winding of stators a number of processes take place. In particular, in the winding a forward current movement begins, which creates the magnetization effect.
  2. Only with matching capacitors parameters of the required capacity, the device is self-excited. This contributes to the emergence of a symmetrical voltage system with 3 phases on the stator winding.
  3. The value of the total voltage will depend on the technical capabilities of the machine used, as well as the capabilities of the capacitors used.

Thanks to the described actions, the process of converting a squirrel-cage induction motor to a generator with similar characteristics occurs.


In everyday life and in production, such generators are widely used in various fields and areas, but they are most in demand for performing the following functions:

  1. Use as engines for wind farms, this is one of the most popular features. Many people make asynchronous generators on their own to use them for this purpose.
  2. Work as a hydroelectric power station with a small output.
  3. Catering and electricity from a city apartment, private country house, or separate household equipment.
  4. Basic functions welding generator.
  5. Uninterrupted equipment alternating current of individual consumers.

Tips for making and operating

It is necessary to have certain skills and knowledge not only in the manufacture, but also in the operation of such machines, the following tips can help:

  1. Any kind of asynchronous generators regardless of the sphere in which they are used, is a dangerous device, for this reason it is recommended to isolate it.
  2. In the process of manufacturing the device it is necessary to think over the installation of measuring instruments, since it will be necessary to obtain data on its functioning and operating parameters.
  3. Special buttons, with which you can control the device, greatly facilitates the operation process.
  4. Grounding is a mandatory requirement that must be implemented before the operation of the generator.
  5. During work, The efficiency of an asynchronous device can periodically decrease by 30-50%, it is not possible to overcome the occurrence of this problem, since this process is an integral part of energy conversion.