Today induction heat generators are widely used. Compared to traditional heating boilers, they are characterized by higher efficiency. In addition, the use of induction heating water heater helps to reduce energy costs. Since factory models of units of this type are expensive, owners of private houses often decide to assemble the device themselves.

Operating principle

Idea to make homemade water heater induction type seems very attractive. Such a unit is practically not inferior in efficiency to factory models, but it will cost the owner of the house a much lower amount. To make a DIY induction heater, three main elements are required:

• Generator.
• A heating element.
• Inductor.

The generator is required to obtain alternating electric current high frequency from a standard home network. A coil made of copper wire is used as an inductor. The purpose of this subassembly is to generate magnetic field. A metal object is used to make the heater capable of absorbing heat energy under the influence of a magnetic field.

DIY simple induction heater

If all these elements are correctly connected, then a powerful electric heater will be obtained, capable of providing heating of a heat-transfer fluid for heating a building. Thanks to the generator, the electric current with the required parameters is supplied to the inductor. This leads to the appearance of a magnetic vortex field on the turns of the coil.

The peculiarity of this field is the ability to change the direction of electromagnetic waves at high frequencies. If you place a metal object in it, then it begins to heat up. Due to the lack of contact, losses will be minimal during the transition of energy from one type to another. Therefore, a self-assembled induction-type boiler has a high efficiency.

To heat the coolant, it is enough to ensure its contact with a metal heater, for example, a tube. This is how it works flow heater... Since the water simultaneously cools the unit, its service life is significantly increased.

INDUCTION HEATER OWN HANDS. HEATING THE METAL

Advantages and disadvantages

Having dealt with the principle of operation of an induction heater, you can consider its positive and negative sides... Given the high popularity of heat generators of this type, it can be assumed that it has much more advantages than disadvantages. Among the most significant advantages are:

Since the performance indicator induction boiler is in a wide range, then you can easily select the unit for a specific building heating system. These devices are capable of quickly heating the coolant to a predetermined temperature, which made them a worthy competitor to traditional boilers.

During the operation of the induction heater, a slight vibration is observed, due to which scale is shaken off the pipes. As a result, the unit can be cleaned less frequently. Since the coolant is in constant contact with the heating element, the risks of its failure are relatively small.

Part 1. INDUCTION BOILER with your own hands - it's easy. Induction hob attachment.

If no mistakes were made during the installation of the induction boiler, then leaks are practically excluded. This is due to the contactless transfer of heat energy to the heater. Using induction water heating technology allows you to bring it almost to a gaseous state... Thus, efficient movement of water through the pipes is achieved, and in some situations it is even possible to do without the use of circulation pumping units.

Unfortunately, there are no ideal devices today. Together with big amount advantages, induction heaters have a number of disadvantages. Since the unit requires electricity to operate, in regions with frequent power outages, it will not be able to work with maximum efficiency... When the coolant overheats, the pressure in the system rises sharply and the pipes can burst. To avoid this, the induction heater must be equipped with an emergency shutdown device.

Depending on your needs, you can make your own induction heater of different power. It may not only be a boiler for heating system, but also a device designed to operate on a voltage of 12 V.

Simple heater

Such a device consists of two main elements - a generator and a coil with a low inductance index. A simple electric heater will operate on a 12V supply. A self-excited generator transmits pulses to an inductor, in which a magnetic field with a frequency of about 35 kHz is generated. When a metal object is placed in the center of the coil, it will start to heat up. At home, this device can be used for non-contact welding, spot heating of the material, and also for hardening metal parts.

It is quite easy to assemble such an inductor according to the circuit with your own hands, since all the necessary radio components are indicated there.

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Instead of Schottky diodes, others can be used. The main requirements for these parts are an operating current of 1 A and sufficient speed. It is not difficult to make an induction coil with your own hands - it is enough to make 10 turns with a tap from the center. The thicker the wire used, the better.

Powerful unit

In industrial units, iron pipes are used as a heater. However, at home, it will be quite difficult to get enough power to heat such elements. However, this does not make much sense. Since the inductor can heat any metal, the homemade heater can be modified. The housing for the unit can be a thick-walled plastic pipe, the material of which can withstand strong heat.

Its length can be about 1 m, and the inner diameter is 50-80 mm. To connect the unit to the heating circuit, it is necessary to install adapters. These devices are mounted in the upper and lower parts of the case. Bottom part plastic pipe closed with a lattice, after which the inner cavity of the body is filled with small iron particles.

When choosing a material for making a filler, you should pay attention to the magnetic resistance indicator. The higher it is, the more actively the material will heat up. The protective grill, installed in the lower part of the housing, is selected depending on the size of the filler particles. When the internal cavity of the case is filled, it is necessary to close it from above with a grid.

The induction coil is wound directly onto the housing heating element... Based on practical experience, to create efficient unit the number of turns must be at least 90. Also remember that there must be no gap between the turns. If this requirement is ignored, noise may be generated during operation. As for the material of the winding, then it is sufficient to use an insulated conductor with a cross section of 1 to 1.5 mm 2.

The heating element must be installed so that its lower part is connected to the return. It is easiest to use an inverter from an old welding machine as a generator. The main requirement here is the ability to adjust the current strength from a minimum level of 10 A. It remains to connect the coil to the inverter and apply the supply voltage to it. The unit will start working immediately afterwards.

During development homemade device it is important to remember his safe operation... To avoid problems, it is worth buying special means emergency shutdown. And industrial products are already equipped with serious means of protection.

Some time ago, we bought a pair of inductive converters in China with the hope that, despite the simplicity of the design and a small number of radio components, this device can then be used in the workshop, for example, as an aid in loosening stuck bolts or for hardening small-sized metals. As it turned out, 100 W of power is very little for these purposes, nevertheless the device works very decently and effectively, no worse than.

Schematic diagram of an induction heater

1 variant of the scheme
2 variant of the scheme

At first glance at the board, you can see that the number of elements is limited. the necessary minimum... The circuit consists of two MOSFETs, two high-speed diodes, two inductors, resistors and resonant elements - that is, an external coil and a large capacitance.

Let's move on to the circuit tests

During the very first tests of the generator, during the determination of the power limit, the transistors burned out. We tried IRFR120 here, but because of the low maximum current, they stood for only a couple of seconds. Then came the turn of the IRFR2905 - these are low-voltage 50 A transistors, with which the heater worked even better than with the original mosfet, where the marking is not visible at all.

When a constant voltage of 12 V is connected, the device consumes about 1.8 A. When a metal object approaches the coil, the current begins to rise. At the peak, it was possible to achieve a current of about 12 A, which gives almost 150 W, that is, even more than the manufacturer claims. During idle, there is about 20 W of power consumption and nothing heats up, which may indicate the correct operation of the entire structure.

A simple transformer power supply was used for the test. During the experiments, three elements were checked for heating: a 6 mm screwdriver, an 8 mm bolt, and the same bolt with two nuts.

As you can see, a medium-sized screwdriver can heat up to the boiling point with this device within 2 minutes. This is quite a decent result. If we can harden the tip of a screwdriver at home, then such a heater will be useful.

It takes about 3 minutes for the bolt to warm up to the boiling point - also good result considering the simplicity of the device.

It took 4 minutes for the bolt with two nuts to warm up - quite a long time. You can use a device in this way to heat a stuck nut in order to unscrew it, but the process will be long and inconvenient. In addition, it may not be possible to completely insert it inside the coil, which will significantly impair the effectiveness of this operation.

An induction heater cost about $ 9, that is, less than 600 rubles. This is a small amount for a device that is able to effectively heat up small metal objects... Of course, this heater cannot be compared with more expensive similar devices for several thousand rubles (which is also on sale on Ali), but for home, amateur or even small workshop applications, it will come in handy.

The induction heater allows you to heat the metal until it turns red without even touching it. The basis of such a heater is a coil, in which a high-frequency field is created, which acts on a metal object placed inside. A high density current is induced in the metal, which causes the metal to heat up. Thus, to create an induction heater, you need a circuit that generates high-frequency oscillations and the coil itself.

Scheme

Above is a diagram of a universal ZVS driver, which is based on powerful field-effect transistors. It is best to use IRFP260, designed for a current of more than 40 A, but if you cannot get them, you can use IRFP250, they are also suitable for this circuit. D1 and D2 are zener diodes, you can use any, for a voltage from 12 to 16 volts. D3 and D4, ultra fast diodes, can be applied, for example, SF18 or UF4007. It is advisable to take resistors R3 and R4 with a power of 3-5 watts, otherwise they may heat up. L1 - inductor, you can take in the range of 10-200 μH. It must be wound with a sufficiently thick copper wire, otherwise it cannot be heated. It is very simple to make it yourself - it is enough to wind 20-30 turns of wire with a cross section of 0.7-1 mm on any ferrite ring. Special attention it is worth giving to the capacitor C1 - it must be designed for a voltage of at least 250 volts. The capacitance can vary from 0.250 to 1 μF. A large current will flow through this capacitor, so it must be massive, otherwise it cannot be heated. L2 and L3 - this is the same coil, inside which the heated object is placed. It consists of 6-10 turns of thick copper wire on a mandrel with a diameter of 2-3 centimeters. On the coil, it is necessary to make a tap from the middle and connect it to the coil L1.

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Assembling the heater circuit

The circuit is assembled on a piece of PCB with dimensions of 60x40 mm. Drawing printed circuit board completely ready to print and does not need to be mirrored. The board is made by the LUT method, below are several photos of the process.

After drilling the holes, the board must be tinned with a thick layer of solder for better conductivity of the tracks, because large currents will flow through them. As usual, sealed first small parts, diodes, zener diodes and 10 kΩ resistors. Powerful 470 Ohm resistors are mounted on the board to save space. To connect the power wires, you can use a terminal block; a place for it on the board is provided. After soldering all the parts, you need to wash off the remnants of the flux and check the adjacent tracks for a short circuit.

Making an induction coil

The coil consists of 6-10 turns of thick copper wire on a mandrel with a diameter of 2-3 centimeters, the mandrel must be dielectric. If the wire keeps its shape well, you can do without it altogether. I used a regular 1.5mm wire and wound it around a piece of plastic pipe. Electrical tape is well suited for fastening the turns.

A tap is made from the middle of the coil, you can simply remove the insulation from the wire and solder the third wire there, as I did. All wires must have a large cross section to avoid unnecessary losses.

First start-up and tests of the heater

The supply voltage of the circuit is in the range of 12-35 volts. The higher the voltage, the more the metal object heats up. But at the same time, the heat generation on the transistors increases - if they hardly heat up when powered by 12 volts, then at 30 volts they may already need a radiator with active cooling. You should also monitor the capacitor C1 - if it heats up noticeably, then you should take a higher voltage one, or collect a battery from several capacitors. At the first start, you will need an ammeter included in the rupture of one of the supply wires. Idling, i.e. in the absence of a metal object inside the coil, the circuit draws about 0.5 amperes. If the current is normal, you can put a metal object inside the coil and watch it literally heat up before your eyes. Happy build.

INDUCTION HEATER Is electric heater operating when changing the flux of magnetic induction in a closed conducting loop. This phenomenon is called electromagnetic induction... Want to know how an induction heater works? ZAVODRR is a trade information portal where you will find information about heaters.

Vortex induction heaters

An induction coil is capable of heating any metal, transistor heaters are assembled and have a high efficiency of more than 95%, they have long replaced lamp induction heaters, whose efficiency did not exceed 60%.

A vortex induction heater for contactless heating has no losses for tuning the resonant coincidence of the operating parameters of the installation with the parameters of the output oscillatory circuit. Vortex heaters assembled on transistors are able to perfectly analyze and adjust the output frequency in automatic mode.

Metal induction heaters

Heaters for induction heating of metal have a contactless method due to the action of the vortex field. Different types of heaters penetrate the metal to a certain depth from 0.1 to 10 cm, depending on the selected frequency:

• high frequency;
• average frequency;
• ultra-high frequency.

Metal induction heaters allow you to process parts not only in open areas, but also to place heated objects in isolated chambers, in which you can create any environment, as well as a vacuum.

Electric induction heater

High Frequency Electric Induction Heater gets new ways of application every day. The heater operates on alternating electric current. Most often, induction electric heaters are used to bring metals to required temperatures in the following operations: forging, brazing, welding, bending, hardening, etc. Electric induction heaters, operate at a high frequency of 30-100 kHz and are used for heating different types environments and coolants.

Electric heater applied in many areas:

• metallurgical (HFC heaters, induction furnaces);
• instrumentation (soldering of elements);
• medical (production and disinfection of instruments);
• jewelry (making jewelry);
• housing and communal ( induction boilers heating);
• food (induction steam boilers).

Medium Frequency Induction Heaters

When deeper heating is required, medium-frequency induction heaters are used, operating at medium frequencies from 1 to 20 kHz. A compact inductor for all types of heaters is the most different shapes, which is selected so as to ensure uniform heating of samples of the most diverse shapes, while a given local heating can be carried out. Medium frequency type will process materials for forging and hardening, as well as through heating for stamping.

Easy to operate, with an efficiency of up to 100%, medium-frequency induction heaters are used for a wide range of technologies in metallurgy (also for melting various metals), mechanical engineering, instrument making and other fields.

High frequency induction heaters

The widest range of applications is for high-frequency induction heaters. The heaters are characterized by a high frequency of 30-100 kHz and a wide power range of 15-160 kW. The high-frequency type provides shallow heating, but this is enough to improve Chemical properties metal.

High frequency induction heaters are easy to operate and economical, while their efficiency can reach 95%. All types operate continuously for a long time, and the two-unit version (when the high-frequency transformer is placed in a separate unit) allows round-the-clock operation. The heater has 28 types of protection, each of which is responsible for its own function. Example: monitoring the water pressure in the cooling system.

Ultra high frequency induction heaters

Microwave-type induction heaters operate at superfrequency (100-1.5 MHz), and penetrate to a heating depth (up to 1 mm). The ultrahigh-frequency type is indispensable for processing thin, small parts with a small diameter. The use of such heaters makes it possible to avoid unwanted deformations accompanying heating.

UHF induction heaters based on JGBT-modules and MOSFET-transistors have a power range of 3.5-500 kW. They are used in electronics, in the production of high-precision instruments, watches, jewelry, for the production of wire and for other purposes that require special precision and delicacy.

Forging induction heaters

The main purpose of forging-type induction heaters (TSC) is to heat parts or their parts prior to subsequent forging. Blanks can be different types, alloy and shape. Induction forging heaters allow automatic processing of cylindrical workpieces of any diameter:

• economical, as they spend only a few seconds on heating and have a high efficiency up to 95%;
• easy to use, allow for: full control of the process, semi-automatic loading and unloading. There are options with full automation;
• reliable and can work continuously for a long time.

Shaft induction heaters

Shaft hardening induction heaters work in conjunction with a hardening complex. The work piece is in a vertical position and rotates inside a stationary inductor. The heater allows all types of rolls to be used for sequential local heating; the hardening depth can be fractions of a millimeter in depth.

As a result of induction heating of the shaft along the entire length with instant cooling, its strength and durability increases many times over.

Induction tube heaters

All types of pipes can be treated with induction heaters. The pipe heater can be air-cooled or water-cooled, with a capacity of 10-250 kW, with the following parameters:

• Induction heating of a pipe with air cooled produced with a flexible inductor and thermal blanket. Heating temperature up to temperature of 400 ° C, and use pipes with a diameter of 20 - 1250 mm with any wall thickness.
• Induction Heating Water Cooled Pipe has a heating temperature of 1600 ° C and is used for bending pipes with a diameter of 20 - 1250 mm.

Each heat treatment option is applied to improve the quality of any steel pipe.

Heating control pyrometer

One of the most important parameters of the operation of induction heaters is temperature. For a more thorough control over it, in addition to built-in sensors, infrared pyrometers are often used. These optical instruments allow you to quickly and easily determine the temperature of hard-to-reach (due to high heat, the possibility of exposure to electricity, etc.) surfaces.

If you connect a pyrometer to an induction heater, you can not only monitor temperature regime but also automatically maintain the heating temperature for a preset time.

The principle of operation of induction heaters

During operation, a magnetic field is generated in the inductor, into which the part is placed. Depending on the task (heating depth) and the part (composition), the frequency is selected, it can be from 0.5 to 700 kHz.

The principle of operation of the heater according to the laws of physics says: when a conductor is in an alternating electromagnetic field, an EMF (electromotive force) is formed in it. The amplitude graph shows that it moves in proportion to the change in magnetic flux velocity. Due to this, eddy currents are formed in the circuit, the magnitude of which depends on the resistance (material) of the conductor. According to the Joule-Lenz law, the current leads to heating of the conductor, which has a resistance.

The principle of operation of all types of induction heaters is similar to that of a transformer. The conductive workpiece, which is located in the inductor, is similar to a transformer (without a magnetic circuit). The primary winding is the inductor, the secondary inductance of the part, and the load is the resistance of the metal. During HFC heating, a "skin effect" is formed, eddy currents that are formed inside the workpiece displace the main current to the surface of the conductor, because the heating of the metal on the surface is stronger than inside.

Benefits of induction heaters

The induction heater has undeniable advantages and is the leader among all types of devices. This advantage is summed up in the following:

• It uses less energy and does not pollute the surrounding area.
• Easy to operate, it provides high quality work and allows you to control the process.
• Heating through the walls of the chamber provides special purity and the ability to obtain ultrapure alloys, while melting can be performed in different atmospheres, including inert gases and in vacuum.
• With its help, uniform heating of parts of any shape or selective heating is possible.
• Finally, induction heaters are versatile, allowing them to be used universally, replacing obsolete energy-intensive and inefficient installations.

Induction heaters are repaired using spare parts from our warehouse. At the moment we can repair all types of heaters. Induction heaters are quite reliable if you strictly follow the operating instructions and avoid extreme operating modes - first of all, monitor the temperature and proper water cooling.

The intricacies of the operation of all types of induction heaters are often not fully published in the manufacturer's documentation; their repair should be carried out by qualified specialists who are well familiar with the detailed principle of operation of such equipment.

Video of operation of induction medium-frequency heaters

You can watch the video of the operation of a medium-frequency induction heater. The middle frequency is used for deep penetration in all types metal products... Medium frequency heater is a reliable and modern equipment that works round the clock for the benefit of your company.

You can make an induction heater yourself if you correctly approach this process Induction heating is modern way heat treatment of electrically conductive substances and materials, which has the highest coefficient useful action among existing methods... For more economical operation of heating and household appliances, today special induction heaters are used. How do they work induction devices and how to make an induction heating device yourself - read below.

• • What is induction heating: advantages
  • Vortex induction heater
  • Circuit board induction heater
  • The simplest do-it-yourself induction heater
  • How to make an induction heater with your own hands: instructions
  • Induction heater made of welding inverter: peculiarities
  • What is an induction heater (video)

The principle of induction heating is based on the effect of alternating current on the transformer winding and the subsequent occurrence of electromagnetic field... As a result of the occurrence of a magnetic field, between magnetic and non-magnetic parts is formed electricity... It is by high-frequency currents (HFC) that various electrically conductive materials are heated.

The advantage of an induction heater is that it is lightweight

Induction heating has many advantages:

• The induction heating device is lightweight, so it can be easily used for domestic purposes;
• Induction heating is ideal for all types of heat treatment of metal, among which welding, brazing, forging are especially popular;
• High-frequency heating can be carried out in a vacuum, protective gas;
• With the help of induction, electrically conductive substances can be quickly and evenly heated, and ultrapure metals can be obtained.

In addition, this heating method is extremely economical: it converts up to 90% of the consumed energy into heat (despite the fact that conventional electric heaters have, on average, rates of 45-50%).

Vortex induction heater

Due to the economic benefits, induction heating today has wide application... The vortex induction heating device is perfect for rooms up to 60 square meters. m, which must be heated with electricity. So, VIN can be used for heating private houses, industrial and storage facilities, Gas station, car service and other detached objects.

The vortex induction heater is quite popular.

The main advantages of using VIN as the “heart” of the heating system include:

• Heating occurs almost instantly, because heat occurs directly in the part;
• Over the years, the installation has been operating at the same capacity, its performance does not decrease;
• Compared to conventional electric heating elements, the induction vortex apparatus saves up to 50% of electricity.

That is why today, more and more companies producing household appliances and production machines use induction heating. An example of such an application, in addition to heating boilers, is an induction electric oven. V Food Industry an ultrasonic induction heater is used. For heating metals in industry, an inverter induction apparatus is used, for melting non-ferrous metals - a smelting-reduction unit, forging iron and making blanks - an induction electric furnace.

Circuit board induction heater

You can make VIN with your own hands. In order to properly assemble a vortex induction heating apparatus, it is necessary to find a diagram of the device. The simplest is a printed circuit board, which is a high-power transistor chopper.

The characteristic differences of this scheme are:

• Heating inductor (coil) in the form of a spiral with 6-8 turns;
• The presence of a voltage regulator (can be taken from an old computer unit);
• The presence of a resistance that protects the transistors from overheating.

Before making a printed circuit board induction heater, you should first familiarize yourself with its diagram.

Transistors in a heater assembled according to this scheme are recommended to be installed on special radiators: this will avoid overheating of the device. An induction water heater can be assembled in the same way.

The vortex induction heater device includes:

• Coil;
• Heat exchanger;
• Terminal box;
• Control cabinet;
• Inlet and outlet branch pipes.

This circuit is based on the resonant principle of operation, which occurs in a serial oscillatory circuit. The magnetic flux between the turns of the coil is closed in the air.

To assemble a heater for hot water heating, it will be easiest to use a circuit with a transformer consisting of primary and secondary short-circuited windings. The water will be heated by passing through the pipes inside the coil and supplied heated from the outlet pipe.

At the same time, it should be remembered that in water heating systems with a view, it is necessary to use a pump for forced circulation water.

If opportunities to establish flow pump no, then you can choose a mechanical heater for the liquid heat carrier as a heating element or attach a permanent magnet heater to the wall of the reservoir with the heat carrier.

The simplest do-it-yourself induction heater

The most budgetary induction generator can be done by taking a transformer magnetic circuit. A sufficiently powerful device for induction heating can be assembled from an electronic transformer, which is a switching power supply.

In order to assemble a simple induction heater, you need to prepare tools for work

In order to assemble the device you need:

1. Solder the main transformer from the electrical one;
2. Make an inductor based on a ferrite cup;
3. Solder the ends of the wires in place pulse unit nutrition.

Such a heater will have an efficiency of at least 65%. This will be enough to build a small induction electric oven. In addition, with the help of such a device, it will be possible to quickly melt wires with a diameter of up to 4 mm.

How to make an induction heater with your own hands: instructions

The induction heating apparatus can be made from the inverter power source of the welding machine. In this case, the design can be simplified by placing a straight pipe inside the induction coil. It will act as a core. In order to make a heater you will need: polymer pipe with a diameter of 5 cm; steel wire with a diameter of 0.6 cm; copper wire by 3mm; construction metal fine mesh.

Before making an induction heater, you can additionally read the detailed instructions.

Getting started:

• We cut the wire rod into lengths of 3-6 mm;
• We close one end of the pipe with a construction mesh;
• We fall asleep inside the pipe pieces of wire;
• We close the second end of the pipe with a mesh;
• We perform winding on top of the pipe (there should be at least 85 and no more than 95 turns);
• We insulate the ends of the winding and connect them to the output of one of the types of welding arc power source.

The device is ready! Now, during the operation of the apparatus, the coil will create an electromagnetic field and eddy current flows. This will cause the fixture to heat up quickly.

Induction heater from welding inverter: features

In its usual form, induction heaters made from a welding inverter pose an increased danger, because they cannot independently control the temperature of the water. Thus, the use of a heater in systems with a coolant can be fraught with short circuits and pipe rupture. This can happen due to the high hydraulic resistance in the system, which occurs due to the movement of the coolant through the pieces of wire rod. Therefore, such devices require improvements.

Practical and high-quality is the induction heater from the welding inverter

To avoid emergency situations should be supplied homemade apparatus induction heating, made of welding inverter, emergency shutdown devices.

To control heating, you can use a thermostat with a temperature temperature sensor and a relay that opens the circuit when the temperature of the coolant reaches the set values. In addition, it will be possible to avoid rupture of the system by attaching a safety valve to the heater through a tee, on one side.

Experienced electricians say that converting one of the types of welding arc power sources into a heater is not justified: heat output the heater will limit electric power inverter.

Such a heat generator is enough to heat a room with an area of ​​no more than 30 square meters. m. Saving money, in this case, will be 30-50% (depending on the size of the apartment). At the same time, you will lose your expensive welding machine today.

What is an induction heater (video)

Inductive heating is a modern method of heat treatment of electrically conductive substances, which has found widespread domestic use. So, vortex induction heaters are excellent for organizing more economical and effective work heating system. You can make an induction generator yourself. The main thing is to take into account the recommendations of professional electricians and carry out all work consistently!