DIY induction bolt heater. Induction heating, basic principles and technologies

The popularity of the IR2153 induction heater can be explained by the fact that a person is always in search - an endless search by a person for heat sources to heat his home, which will be: economical, environmentally friendly and functional. Many even dared, and for good reason, to make an induction heater with their own hands in order to connect it to the heating system of their home. The article will describe in detail how to make an inductor heater in order to spend a minimum Money and time.

Induction heater circuit

Due to the fact that M. Faraday discovered the phenomenon of electromagnetic induction back in 1831, the world saw a large number of devices that heat water and other media.

Because this discovery was realized, people use it in everyday life:

• Electric kettle with disk heater for heating water;
• Multicooker oven;
• Induction hob;
• Microwaves (stove);
• Heater;
• Heating column.

The opening is also used for an extruder (not mechanical). Previously, it was widely used in metallurgy and other industries related to metal processing. A factory-made induction boiler operates on the principle of the action of eddy currents on a special core located in the internal part of the coil. Foucault eddy currents are superficial, so it is better to take a hollow metal pipe as a core through which the coolant element passes.

The occurrence of electric currents occurs due to the supply of alternating electrical voltage to the winding, causing the appearance of alternating electrical magnetic field, which changes potentials 50 times/sec. at a standard industrial frequency of 50 Hz.

In this case, the Ruhmkorff induction coil is designed in such a way that it can be connected to the electrical network alternating current directly. In production, high-frequency electric currents are used for such heating - up to 1 MHz, so it is quite difficult to achieve the operation of the device at 50 Hz. The thickness of the wire and the number of winding turns used by the device, water heater, are calculated separately for each unit according to special method for the required heat output. A homemade, powerful unit must function efficiently, quickly heat the water flowing through the pipe and not heat up.

Organizations invest serious funds in the development and implementation of such products, therefore:

• All problems are resolved successfully;
• The efficiency of the heating device is 98%;
• Functions without interruption.

In addition to the highest efficiency, one cannot help but be attracted by the speed at which the medium passing through the core is heated. In Fig. A diagram of the functioning of an induction water heater created at the plant is proposed. Such a scheme has a unit of the “VIN” brand, which is produced by the Izhevsk plant.

How long the unit will operate depends solely on how sealed the housing is and how the insulation of the wire turns is not damaged, and this is quite a significant period, according to the manufacturer - up to 30 years.

For all these advantages, which the device 100% has, you need to shell out a lot of money; an induction, magnetic water heater is the most expensive of all types of heating installations. Therefore, many craftsmen prefer to assemble an ultra-economical heating unit themselves.

Making an induction heater with your own hands

Making an invention is not difficult, if you have the skills, you can do it good device. The simplest unit, which is assembled by hand, consists of a piece of pipe (plastic), inside which various elements (metal) are arranged to create a core.

It could be:

• Stainless steel wire;
• Wire rolled into balls, chopped into small pieces - wire rod, the diameter of which is 8 mm;
• Drill according to pipe diameter.

On the outside, fiberglass sticks are glued to it, and a 1.7 mm thick wire in insulation needs to be wound around them. The length of the wire is approximately 11 m. Then the induction heater must be tested by filling it with water and connecting it, for example, to an ORION induction hob with a power of 2 kW instead of the standard inductor. A vortex radiator welded from several metal pipes acts as an external core for eddy currents created by a coil of the same panel.

As a result, we can draw the following conclusion:

1. The heat power of the manufactured heating device is higher than the electrical power of the panel.
2. The number and size of the tubes were chosen randomly but provided sufficient surface area for the heat generated by the eddy currents.
3. This water heater design turned out to be successful for a specific case when the apartment space is surrounded by other apartments that are heated.

The device works correctly, so if you have the desire, experience and knowledge, you can bring this idea to life. For complex models It may be necessary to use a 3-phase transformer.

High precision induction heating

This heating has the simplest principle, since it is non-contact. High-frequency pulse heating makes it possible to achieve the highest temperature conditions, at which it is possible to process the most difficult metals to melt. To perform induction heating, you need to create electromagnetic fields the required voltage is 12V (volts) and the frequency of the inductance.

This can be done in a special device - an inductor. It is powered by electricity from an industrial power supply at 50 Hz.

It is possible to use individual power supplies for this – converters/generators. The simplest device for a low-frequency device is a spiral (insulated conductor), which can be placed in the inside of a metal pipe or wound around it. The flowing currents heat the tube, which subsequently supplies heat to the living space.

The use of induction heating at minimum frequencies is not common. The most common processing of metals is at higher or medium frequencies. Such devices are distinguished by the fact that the magnetic wave travels to the surface, where it attenuates. The energy is converted into heat. For the best effect, both components must have a similar shape. Where is heat applied?

Application today high frequency heating widespread:

• For melting metals and soldering them using a non-contact method;
• Mechanical engineering industry;
• Jewelry;
• Creation of small elements (boards) that can be damaged when using other techniques;
• Hardening of surfaces of parts of various configurations;
• Heat treatment of parts;
• Medical practice (disinfection of devices/instruments).

Heating can solve many problems.

Advantages: induction heating of metal

Heating has many benefits. With it, it is possible to quickly heat and melt to liquid state any conductive material. Makes it possible to perform heating in any environment that does not conduct current, that is, the melting-working function.

Because only the conductor heats up, the walls remain cold. This type of heating does not pollute environment. If gas burners pollute the air, then induction heating eliminates this, because of how electromagnetic radiation works. Compact dimensions of the inductor. Possibility of creating a device of any shape.

Heating is indispensable if you need to heat only a selected area on the surface. The device can also configure such special equipment to the required mode and adjust it.

How to make an induction heater from a computer power supply

The heater can be made from a computer power supply.

Will need:

• Throttle from the computer unit;
• Soldering iron;
• Welding machine;
• Wire cutters;
• Stainless steel wire 6 mm;
• Enameled flat copper wire 2mm;
• Steel pipes 25 mm;
• Plastic pipe 50 mm;
• Durable sanitary fittings;
• Explosion valve;
• Parts for assembling the circuit.

The boiler consists of a coil, a heat exchanger, a terminal box, a control cabinet, inlet and outlet pipes. The installation is simple, the main thing is to follow the diagram. A good laboratory power supply can be developed in a day and implemented in a day. Devices are connected through a transformer point.

Simple DIY inductor

A HDTV inductor can often come in handy in home life.

This device is often used to heat stuck:

• Nuts/bolts;
• Car frames and beams;
• Parts for car service, including bearings and various bushings.

Such devices can be bought in a specialized store, just like any other equipment, for example, an inverter Chinese air conditioner, a seismic sensor, but they are very expensive. However, there is a way out; it is quite possible to create an induction heater at home. For assembly you will need a transformer, it can be made from 2 rings. Ferrite grade can be used M 2000 NM.

The primary winding should contain approximately 26 turns of wire with a diameter of 0.75 mm. The primary winding is connected where the inverter comes out. The second winding consists of one loop of a copper tube with a diameter of 6 mm, which is also the outlet of the inductor-tube, which passes through the center of the annular part of the transformer.

The inductor itself is a coil of several turns of a copper tube - 4 mm.

The capacitor, together with the device, performs the work of an oscillation circuit that creates a resonance frequency (resonance) to which the inverter is tuned. If a workpiece is placed in the central part of the copper spiral, it will provide active resistance. High frequency frequencies arise in the coil itself, so the tube with the coils gets very hot, which means it must be cooled, for this it is possible to use plain water from pipelines.

To supply the inductor, it is necessary to use dielectric tubes, since the circuit develops high voltage. Behind running water that cools the inductor requires constant monitoring, so a special insert is installed in the drain, to which a thermocouple and a tester are attached to monitor temperature regime. The device should use a powerful capacitor; it can be assembled from forty high-voltage capacitors of 0.033 μF each.

DIY induction heater (video)

As you can see, making an inductor with your own hands is not difficult, the main thing is to follow the diagram, you can also create an induction horn or assemble a circuit using thyristors or any other, for example, the internal contents of a transistor.

Electric heaters are very popular, they are at the same time completely safe to use, functional and efficient. A self-made induction heater can be used to heat water or become the basis of an entire heating system in a private home. You just need to pick high-quality scheme manufacturing, which will allow us to make reliable and universally usable equipment.

A similar heater - effective remedy for heating

Description and advantages of the technology

The operating principle of induction heaters is based on the release of heat by metals when current is passed through them. When voltage is applied to a current-carrying circuit, a magnetic field and induction current are generated, which generates a large amount of heat. Today, based on this technology, various electric heaters are manufactured, which at the same time combine compact dimensions and excellent power. Due to the simplicity of the design of such installations, making them yourself will not be difficult.

One of the advantages of this heater is almost 100% efficiency

The advantages of induction heating include the following:

1. High power.
2. Ability to work in various environments.
3. Completely environmentally friendly.
4. Possibility of selective heating.
5. Full automation of the process.
6. Efficiency is 99%.
7. Long service life.

In everyday life, induction heating technologies are implemented in kitchen stoves and fully automated heating boilers. Such installations are popular in the domestic market, due to their ease of maintenance, reliable design, efficiency and versatility of use.

The design of an induction heater is so simple that assembling it with your own hands is not difficult. You will only need minimal experience in reading schematics and the ability to work with a soldering iron or similar equipment. You can make the simplest versions of heaters for heating indoor air, or make a full-fledged boiler for a country house.

In this video you will learn how to make a simple induction heater

Operating principle of the equipment

Induction heating technology is distinguished by its efficiency and simplicity of its design. Today, two types of induction are widespread:

• Vortex heaters.
• Devices with electronically controlled and currents in the coil.

During production homemade heaters Vortex types of induction are used, which is explained by the simplicity of their implementation and excellent efficiency. The operating principle of such equipment is based on the transfer of energy to the coolant from a magnetic field. Powerful radiation is generated in a metal current-conducting inductor. When an electric current passes through a metal coil, it creates powerful vortex currents, with their subsequent transformation into thermal energy.

The heat exchanger of such a boiler can be made in the form of a conventional column, into which water enters from below under pressure, and induction heating is carried out along the entire height. The heated coolant leaves the boiler through the upper pipe and is directed into the closed circuit of the heating system. Constant circulation of water in the boiler prevents overheating of the elements, which ensures the highest possible safety of using such equipment.

The formation of scale is prevented due to the slight vibration of the coolant as it passes through the heat exchanger, which eliminates the appearance of calcium deposits, and saves the homeowner from the need for any cleaning and other maintenance of induction equipment.

Manufacturing of induction heaters

Induction heating is not yet as popular as gas and solid fuel boilers. This can be explained by the high cost of such heating systems for private houses. For household use a boiler built on induction technology will cost 30,000 rubles and more. Therefore, it is not surprising that many homeowners refuse to buy factory-made equipment and make it themselves. If you have the appropriate diagram, inexpensive components and the ability to read technical documentation, you can create an effective and completely safe induction heater for a heating boiler in just a few hours.

Transformer based

High-quality induction heating elements can be made on the basis of a transformer with a primary and secondary winding. The eddy currents necessary for the operation of such equipment are formed in the primary winding and create an induction field. A powerful electromagnetic field affects the secondary winding, which is essentially an induction heater and emits a large amount of heat used to heat the coolant.

The design of a homemade induction heater based on a transformer will include the following elements:

1. Transformer core.
2. Winding.
3. Heat and electrical insulation.

The core is made in the form of two ferromagnetic tubes with different diameters. They are welded into each other, after which a toroidal winding is made of durable copper wire. At least 85 turns are made making sure to maintain an equal distance between them. When electricity is passed through the core and winding in a closed loop, eddy currents are created that heat the core and secondary winding. Subsequently, the resulting heat is used to heat the coolant.

From high frequency welding machine

In a DIY inductor circuit using a high-frequency inverter, the main elements are an alternator, heating elements and inductors. A generator will be needed to convert standard voltage with a frequency of 50 Hertz into high-frequency electric current. After modulation, the current is supplied to the inductor coil, which has a cylindrical shape. The coil winding is made of copper wire, which allows you to generate a magnetic alternating field that creates the necessary eddy currents, due to the appearance of which the metal body of the water jacket is heated. The resulting heat is transferred to the coolant.

Create a high-quality heater based on high-frequency welding inverter won't be difficult. You just need to take care of high-quality and reliable thermal insulation, which will ensure the highest possible efficiency indicators. Otherwise, in the absence of reliable thermal insulation, the efficiency of the heating system is significantly reduced, which leads to significant energy consumption for the operation of the equipment.

There are at least 3 main elements that must be in working order in the heater

Heater assembly steps

Making a simple induction metal heater with your own hands is not difficult. For this work you will need the following tools:

1. Radioelements.
2. Mini drill.
3. Textolite boards.
4. Soldering iron and solder.
5. Chemical reagents for soldering.
6. Thermal paste.

To make a coil that is used to emit an alternating magnetic field, you will need to prepare a piece of copper tube with a length of 800 millimeters and a diameter of 8 millimeters.

Of the components used, the most expensive are high-power power transistors, of which at least two must be installed. IRFP 150, IRFP260 or IRFP460 are suitable for this type of work.

You can make an oscillating circuit of a water heater using ceramic capacitors with a voltage of 1600 Volts and a capacity of 0.1 mF. To generate high power AC current in the coil, you will need to use at least 7 of these 12 V capacitors.

During operation, field-effect transistors can become very hot. Without the use of high-quality aluminum radiators, they will melt literally within a few seconds after voltage is applied to the transformer. Heat sinks and radiators are placed on transistors through thermal paste, otherwise the cooling efficiency will not be too high.

Diodes for induction wine heaters use ultra-fast action. Models HER 307, UF 4700, MUR 460 are best suited for this scheme.

You will also need to purchase two resistors with a capacity of 10 kOhm and a power of approximately 0.25 W, one resistor with a power of 2 Watt with a capacity of 440 Ohm. You will need to use two zener diodes with a voltage of 15 Volts. Their optimal power is at least 2 watts. TO power wires, which supply voltage to the coil, install a standard inductor.

The heater is powered by a power supply with a voltage of 12-40 Volts and a power of no more than 500 W. You can use car batteries or a power supply from an old computer.

From copper pipe Using the existing template, a spiral with a diameter of about 4 centimeters is made. It must have at least 7 turns that do not touch each other. At the end of the second tube, ferromagnetic fastening rings are welded, which will be required to connect the transistors to the radiator.

The printed circuit board is made according to a circuit that allows the conversion of standard current into powerful and high-frequency current. At large voltage amplitudes, a self-made heater will operate stably, consuming a minimum of electricity and providing high-quality heating. Capacitors are installed on printed circuit board in parallel, forming an oscillatory circuit with the coil.

A test run is performed, during which the spring windings are monitored for short circuits. If there are short circuits and the coil turns come into contact with each other, the transistors will instantly fail, and a self-made inductor heater will require expensive repairs.

Inside the induction coil, a heat exchanger housing can be installed through the insulation, inside which the heated liquid will circulate. Due to its high efficiency, induction heating technology even at minimum consumption electricity ensures the release of a large amount of thermal energy, which allows high-quality heating of the room.

The heat exchanger is made of a pipe with a diameter of 20 millimeters, which is made of stainless steel. One or more induction coils are threaded onto such a pipe, while metal elements should not come into contact with the coils of the volute, which is under voltage. With a power rating of 2 kW, the efficiency of such a device will be sufficient to ensure flow-through heating of liquid with its subsequent use for technical purposes or for heating a room.

Induction heaters are promising technology, which today is actively used in the manufacture of autonomous heating boilers. The simplicity of the implementation scheme for such electrical appliances allows you to implement them yourself. By making such an inductive heater with your own hands, you can save on the purchase of expensive equipment, while still being functional homemade devices will not be inferior to expensive factory heater models.

INDUCTION HEATER- it's 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, heaters are assembled using transistors 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 non-contact heating has no losses in adjusting the resonant coincidence of the operating parameters of the installation with the parameters of the output oscillatory circuit. Vortex-type 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 non-contact method due to the action of a 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 Every day it acquires new ways of application. The heater operates on AC electric current. Most often, induction electric heaters are used to bring metals to the required temperatures during the following operations: forging, soldering, welding, bending, hardening, etc. Electric induction heaters operate at high frequency 30-100 kHz and are used for heating various types media and coolants.

Electric heater used in many areas:

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

Medium Frequency Induction Heaters

When deeper heating is required, medium-frequency type induction heaters are used, operating at medium frequencies from 1 to 20 kHz. Compact inductor for all types of heaters comes in the most different shapes, which is selected so as to ensure uniform heating of the samples itself various shapes, in this case it is possible to carry out the specified local heating. The mid-frequency type will process materials for forging and hardening, as well as through heating for stamping.

Easy to operate, with efficiency up to 100%, induction mid-frequency heaters are used for a wide range of technologies in metallurgy (also for smelting 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 the chemical properties of the metal.

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

Ultra High Frequency Induction Heaters

Microwave induction heaters operate at superfrequencies (100-1.5 MHz) and penetrate to a heating depth (up to 1 mm). The ultra-high-frequency type is indispensable for processing thin, small, small-diameter parts. The use of such heaters allows one to avoid unwanted deformations associated with heating.

Ultra-high-frequency induction heaters based on JGBT modules and MOSFET transistors have power limits 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 requiring special precision and filigree.

Forge induction heaters

The main purpose of forging-type induction heaters (IH) is heating of parts or parts thereof, prior to subsequent forging. The blanks can be the most different types, alloy and shape. Induction forging heaters allow you to process cylindrical workpieces of any diameter in automatic mode:

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

Induction shaft heaters

Induction heaters for hardening shafts work together with the hardening complex. The workpiece is in a vertical position and rotates inside a stationary inductor. The heater allows the use of all types of shafts for consistent local heating; the hardening depth can be fractions of millimeters in depth.

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

Induction pipe heaters

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

• Air Cooled Tube Induction Heating produced using a flexible inductor and a thermal blanket. Heating temperature up to temperature 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 used to improve the quality of any steel pipe.

Pyrometer for heating control

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

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

Operating principle of induction heaters

During operation, a magnetic field is formed in the inductor, into which the part is placed. Depending on the task (depth of heating) 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 states: when a conductor is in an alternating electromagnetic field, an EMF (electromotive force) is formed in it. The amplitude graph shows that it moves proportionally to the change in the speed of the magnetic flux. 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, current leads to heating of a conductor that has resistance.

The operating principle of all types of induction heaters is similar to a transformer. The conductive workpiece, which is located in the inductor, is similar to a transformer (without a magnetic core). The primary winding is an inductor, the secondary inductance of the part, and the load is the metal resistance. During high-frequency heating, a “skin effect” is formed; eddy currents that form inside the workpiece displace the main current onto the surface of the conductor, because the heating of the metal on the surface is stronger than inside.

Advantages of induction heaters

Induction heater has undoubted advantages and is a leader among all types of devices. This advantage is as follows:

• It consumes less electricity and does not pollute the surrounding space.
• Easy to use, it provides high quality work and allows you to control the process.
• Heating through the walls of the chamber ensures special purity and the ability to obtain ultra-pure alloys, while melting can be carried out in different atmospheres, including inert gases and vacuum.
• With its help, it is possible to uniformly heat parts of any shape or selective heating
• Finally, induction heaters are universal, which allows them to be used everywhere, displacing outdated energy-consuming and inefficient installations.

Repair of induction heaters is carried out 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 do not allow excessive operating conditions - first of all, monitor the temperature and proper water cooling.

The subtleties of operation of all types of induction heaters are often not fully published in the manufacturers' documentation; their repairs should be carried out by qualified specialists who are well acquainted with the detailed operating principle of such equipment.

Video of induction mid-frequency heaters working

You can watch a video of the operation of a medium-frequency induction heater.. Average frequency is used for deep penetration in all types metal products. The medium frequency heater is a reliable and modern equipment, which works around the clock for the benefit of your enterprise.

Some time ago, we bought a pair of inductive converters in China with the hope that, despite the simplicity of the design and the small number of radio components, it would be possible to later use this device 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, however, the device works very well and effectively, no worse than.

Schematic diagram of an induction heater

1 scheme option
Scheme option 2

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 testing the circuit

During the first tests of the generator, while determining the power limit, the transistors burned out. We tried IRFR120 here, but due to the low maximum current they only lasted 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 markings are not visible at all.

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

For the test, a simple transformer power supply was used. During the experiments, three elements were tested 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 worthy result. If we can harden the tip of a screwdriver at home, then such a heater will be useful.

It takes about 3 minutes to heat the bolt to the boiling point - also a good result, given the simplicity of the device.

Warming up the bolt with two nuts took 4 minutes - quite a long time. You can use devices 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 into the coil, which will significantly impair the effectiveness of this operation.

The induction heater cost about 9 dollars, that is, less than 600 rubles. This is a small amount for a device that can effectively heat small metal objects. Of course, you can’t compare this heater with more expensive similar devices costing several thousand rubles (which are also available on Ali), but for home, amateur, or even small workshop applications it is quite useful.

Induction heaters work on the principle of “derived current from magnetism”. A high-power alternating magnetic field is generated in a special coil, which generates eddy electric currents in a closed conductor.

The closed conductor in induction cookers is metal utensils, which is heated by eddy electric currents. In general, the operating principle of such devices is not complicated, and if you have a little knowledge of physics and electrical engineering, assembling an induction heater with your own hands will not be difficult.

The following devices can be made independently:

1. Devices for heating in a heating boiler.
2. Mini ovens for melting metals.
3. Plates for cooking food.

A do-it-yourself induction cooker must be manufactured in compliance with all standards and regulations for the operation of these devices. If electromagnetic radiation dangerous to humans is emitted outside the housing in lateral directions, then the use of such a device is strictly prohibited.

In addition, the great difficulty in designing a stove lies in the selection of material for the base of the hob, which must meet the following requirements:

1. Ideally conduct electromagnetic radiation.
2. Not a conductive material.
3. Withstand high temperature load.

In household cookers induction surfaces Expensive ceramics are used when made at home induction cooker, finding a worthy alternative to such material is quite difficult. Therefore, first you should design something simpler, for example, an induction furnace for hardening metals.

Manufacturing instructions

Blueprints

Figure 1. Electrical circuit of an induction heater
Figure 2. Device. Figure 3. Schematic of a simple induction heater

To make a furnace you will need following materials and tools:

• solder;
• textolite board.
• mini drill.
• radioelements.
• thermal paste.
• chemical reagents for etching the board.

Additional materials and their features:

1. For making a coil, which will emit the alternating magnetic field necessary for heating, it is necessary to prepare a piece of copper tube with a diameter of 8 mm and a length of 800 mm.
2. Powerful power transistors are the most expensive part of a homemade induction installation. To install the frequency generator circuit, you need to prepare 2 such elements. Transistors of the following brands are suitable for these purposes: IRFP-150; IRFP-260; IRFP-460. When manufacturing the circuit, 2 identical of the listed field-effect transistors are used.
3. For the manufacture of an oscillatory circuit you will need ceramic capacitors with a capacity of 0.1 mF and an operating voltage of 1600 V. In order for high-power alternating current to form in the coil, 7 such capacitors will be required.
4. When operating such an induction device, field-effect transistors will get very hot and if radiators from aluminum alloy, then after just a few seconds of operation at maximum power, these elements will fail. Transistors should be placed on heat sinks through a thin layer of thermal paste, otherwise the effectiveness of such cooling will be minimal.
5. Diodes, which are used in an induction heater, must be ultra-fast acting. The most suitable diodes for this circuit are: MUR-460; UF-4007; HER – 307.
6. Resistors used in circuit 3: 10 kOhm power 0.25 W – 2 pcs. and 440 Ohm power - 2 W. Zener diodes: 2 pcs. with an operating voltage of 15 V. The power of the zener diodes must be at least 2 W. A choke for connecting to the power terminals of the coil is used with induction.
7. To power the entire device you will need a power supply with a power of up to 500 W. and voltage 12 - 40 V. You can power this device from a car battery, but you won’t be able to get the highest power readings at this voltage.

The manufacturing process of the electronic generator and coil itself takes a little time and is carried out in the following sequence:

1. From copper pipe a spiral with a diameter of 4 cm is made. To make a spiral, you should copper tube screw onto a rod with a flat surface with a diameter of 4 cm. The spiral should have 7 turns, which should not touch. Fastening rings are soldered to the 2 ends of the tube for connection to the transistor radiators.
2. The printed circuit board is made according to the diagram. If it is possible to install polypropylene capacitors, then due to the fact that such elements have minimal losses and stable operation at large amplitudes of voltage fluctuations, the device will operate much more stable. The capacitors in the circuit are installed in parallel to form an oscillating circuit with a copper coil.
3. Heating the metal occurs inside the coil after the circuit is connected to the power supply or battery. When heating the metal, it is necessary to ensure that there is no short circuit in the spring windings. If you touch 2 turns of the coil at the same time with heated metal, the transistors will fail instantly.

Nuances

1. When conducting experiments on heating and hardening of metals, inside the induction coil the temperature can be significant and amounts to 100 degrees Celsius. This thermal heating effect can be used to heat water for domestic use or for heating a home.
2. Diagram of the heater discussed above (Figure 3), at maximum load is capable of providing radiation of magnetic energy inside the coil equal to 500 W. This power is not enough to heat a large volume of water, and the construction of a high-power induction coil will require the manufacture of a circuit in which it will be necessary to use very expensive radio elements.
3. Budget solution for organizing induction heating of liquids, is the use of several devices described above, located in series. In this case, the spirals must be on the same line and not have a common metal conductor.
4. AsA stainless steel pipe with a diameter of 20 mm is used. Several induction spirals are “strung” onto the pipe, so that the heat exchanger is in the middle of the spiral and does not come into contact with its turns. At simultaneous switching on 4 such devices, the heating power will be about 2 kW, which is already sufficient for flow-through heating of liquid with a small circulation of water, to values ​​​​allowing the use this design in supply warm water small house.
5. If you connect this a heating element with well insulated tank, which will be located above the heater, the result will be a boiler system in which the liquid will be heated inside stainless pipe, the heated water will rise up, and its place will be taken by a colder liquid.
6. If the area of ​​the house is significant, then the number of induction coils can be increased to 10 pieces.
7. The power of such a boiler can be easily adjusted by turning off or turning on the spirals. The more sections that are turned on at the same time, the greater the power of the heating device operating in this way.
8. To power such a module you will need a powerful power supply. If inverter is available welding machine direct current, then a voltage converter of the required power can be made from it.
9. Due to the fact that the system operates on constant electric current, which does not exceed 40 V, the operation of such a device is relatively safe, the main thing is to provide a fuse block in the generator power circuit, which in the event of a short circuit will de-energize the system, thereby eliminating the possibility of a fire.
10. You can organize “free” home heating in this way., subject to installation for powering induction devices batteries, which will be charged using solar and wind energy.
11. The batteries should be combined into sections of 2, connected in series. As a result, the supply voltage with such a connection will be at least 24 V, which will ensure the boiler operates at high power. Besides, serial connection will reduce the current in the circuit and increase the service life of the batteries.

1. Exploitation homemade devices induction heating, does not always eliminate the spread of electromagnetic radiation harmful to humans, so the induction boiler should be installed in a non-residential area and shielded with galvanized steel.
2. Mandatory when working with electricity safety regulations must be followed and, especially this applies to AC networks with a voltage of 220 V.
3. As an experiment can be made hob for cooking food according to the scheme specified in the article, but it is not recommended to use this device constantly due to imperfections self-made shielding of this device, because of this, the human body may be exposed to harmful electromagnetic radiation that can adversely affect health.