Do-it-yourself induction heater diagram. Diagram of an induction heater

Here is a project of an induction heater for metals of the simplest design, it is assembled according to the multivibrator circuit and often acts as the first heater that radio amateurs make.

The principle of operation of the HDTV installation

The coil creates a high-frequency magnetic field, and eddy currents appear in the metal object in the middle of the coil, which will heat it up. Even small coils pump current around 100 A, so a resonant capacitance is connected in parallel with the coil, which compensates for its inductive nature. The coil-capacitor circuit must operate at their resonant frequency.

HDTV coil homemade

Schematic electrical diagram

Scheme of an induction heater from 12V

Here is the original circuit of the induction heater generator, and below it is a slightly modified version, according to which the design of the mini HDTV installation was assembled. There is nothing scarce here - you only have to buy field-effect transistors, you can use BUZ11, IRFP240, IRFP250 or IRFP460. The capacitors are special high-voltage, and the power will be from a 70 A / h car battery - it will hold current very well.

The project turned out to be surprisingly successful - everything worked, although it was assembled “on the knee” in an hour. I was especially pleased that it does not require a 220 V network - auto batteries allow you to power it even in the field (by the way, can you make a camping microwave out of it?). You can experiment in the direction to reduce the supply voltage to 4-8 V as from lithium batteries (for miniaturization) while maintaining good heating efficiency. Of course, it will not work to melt massive metal objects, but it will do for small works.

The current consumption from the power supply is 11 A, but after warming up it drops to about 7 A, because the resistance of the metal increases noticeably when heated. And do not forget to use thick wires here that can withstand more than 10 A of current, otherwise the wires will become hot during operation.

Heating a screwdriver to blue HDTV

Knife heating HDTV

The second version of the circuit - with mains power

To make it more convenient to adjust the resonance, you can assemble a more advanced circuit with an IR2153 driver. The operating frequency is adjusted by the 100k regulator to resonance. Frequencies can be controlled in the range of approximately 20 - 200 kHz. The control circuit needs an auxiliary voltage of 12-15 V from a network adapter, and the power section can be connected directly to a 220 V network through a diode bridge. The inductor has about 20 turns of 1.5 mm on an 8 × 10 mm ferrite core.

Diagram of an induction heater from a 220V network

The working coil of the HDTV should be made of thick wire or better than a copper tube, and has about 10-30 turns on a 3-10 cm mandrel. Capacitors 6 x 330n 250V. Both get hot after a while. The resonant frequency is about 30 kHz. This homemade induction heating unit is assembled in a plastic case and has been operating for more than a year.

Many people are attracted to electric heating by the fact that it works autonomously and does not need to be constantly looked after. The negative side of such heating boilers is the cost and technical requirements.

In some places, they simply cannot be applied. But many owners are not afraid of this, and they believe that it is the ease of operation that covers all the shortcomings.

Especially when new types appeared on the markets with inductive coils, and not TENs. They heat up the building with instantaneous speed and economically heat the building, according to the owners of the units. The new type of boilers is called induction.

The new type of heaters is convenient in operation. They are considered safe, in comparison with gas heaters, there is no soot and soot, which cannot be said about solid fuel appliances. And the most important advantage is that there is no need to procure solid fuel (coal, firewood, etc.).

And as soon as induction heaters appeared, there were immediately craftsmen who, in order to save money, are trying to create such an installation with their own hands.

In this article, we will help you design a heating device yourself.

A device where metal and similar products are heated without contact is called an induction heater. The work is controlled by an alternating induction field acting on the metal, and the currents inside form heat.

High frequency currents affect products in addition to insulation, which is why the design is extraordinary compared to other types of heating.

In today's induction heaters there are semiconductor frequency reducers. This type of heating is widely used in the heat treatment of surfaces made of steel and various compounds and alloys.

The compactness of the equipment is used in innovative technologies, while there is a huge economic effect. A variety of models help implement flexible and automated combinations, including all-round type transistor frequency reducers and connection blocks when an induction system is preferred.

Description

Heater device

The composition of a typical heating element includes the following components:

Heating element in the form of a rod or a metal tube.
Inductor- This is a copper wire framing the coil with turns. During operation, it plays the role of a generator.
Alternator. A separate structure where the standard current is converted into a value with a high frequency.

In practice, induction installations are used recently. Theoretical studies are far ahead. This can be explained by one obstacle - obtaining a high frequency of magnetic fields. The fact is that using low-frequency settings is considered inefficient. As soon as they appeared with a high frequency, the problem was resolved.

HDTV generators have passed their evolutionary period; from lamp to modern models based on IGBT. Now they are more efficient, have a small weight and dimensions. Their frequency limitation is 100 kHz due to the dynamic losses of transistors.

Principle of operation and scope

The generator increases the frequency of the current and transfers its energy to the coil. The inductor converts high-frequency current into an alternating electromagnetic field. Electromagnetic waves change with high frequency.

Heating occurs due to the heating of eddy currents, which are provoked by variable eddy vectors of the electromagnetic field. Energy with high efficiency is transmitted almost without loss and there is enough energy to heat the coolant and even more.

The battery energy is transferred to the coolant, which is located inside the pipe. The heat carrier, in turn, is the cooler of the heating element. As a result, the service life is increased.

The industry is the most active consumer of induction heaters, as many designs involve high heat treatment. With their use, the strength of products increases.

In high-frequency forges, devices with high power are installed.

Forging and pressing companies, using such units, increase labor productivity and reduce the wear of dies, reduce metal consumption. Installations with through heating can cover a certain number of workpieces at once.

In case of surface hardening of parts, the use of such heating makes it possible to increase wear resistance several times and obtain a significant economic effect.

The generally accepted field of application of devices is soldering, melting, heating before deformation, HDTV hardening. But there are still zones where single-crystal semiconductor materials are obtained, epitaxial films are built up, materials are foamed into el. field, high-frequency welding of shells and pipes.

Advantages and disadvantages

Pros:

High quality heating.
High control precision and flexibility.
Reliability. It can work autonomously with automation.
Heats any liquid.
The efficiency of the device is 90%.
Long service life(up to 30 years).
Ease of mounting.
The heater does not collect scale.
Due to automation, energy savings.

Minuses:

The high cost of models with automation.
Dependence on power supply.
Some models are noisy.

How to do it yourself?

Wiring diagram of the induction heater

Let's say you decide to make an induction heater yourself, for this we prepare a pipe, pour small pieces of steel wire (9 cm in length) into it.

The pipe can be plastic or metal, most importantly, with thick walls. Then, it is closed with special adapters from all sides.

Next, we wind copper wire on it up to 100 turns and place it in the central part of the tube. The result is an inductor. We connect the output part of the inverter to this winding. As an assistant, we resort to.

The pipe acts as a heater.

We prepare the generator and assemble the entire structure.

Required materials and tools:

stainless steel wire or wire rod (diameter 7 mm);
water;
enameled copper wire;
metal mesh with small holes;
adapters;
thick-walled plastic pipe;

Walkthrough:

Mode wire into pieces, 50 mm long.
We prepare the shell for the heater. We use a thick-walled pipe (diameter 50 mm).
We close the bottom and top of the case with a net.
Preparing the induction coil. With a copper wire, we wind 90 turns on the body and place them in the center of the shell.
Cut out part of the pipe from the pipeline and install an induction boiler.
We connect the coil to the inverter and fill the pot with water.
We ground the resulting structure.
We check the system in operation. Do not use without water, as the plastic pipe may melt.

From a welding inverter

The simplest budget option is to manufacture an induction heater using a welding inverter:

To do this, take a polymer pipe, its walls should be thick. From the ends we mount 2 valves and connect the wiring.
Pour the pieces into the pipe(diameter 5 mm) metal wire and mount the top valve.
Next, we make 90 turns around the pipe with copper wire, we get an inductor. The heating element is a pipe, we use a welding machine as a generator.
The device must be in AC mode. with high frequency.
We connect the copper wire to the poles of the welding machine and check the work.

Working as an inductor, a magnetic field will be radiated, while eddy currents will heat up the chopped wire, which will lead to boiling water in the polymer pipe

Open sections of the structure, for safety reasons, should be isolated.
The use of an induction heater is recommended only in closed heating systems, where a pump is equipped to circulate the coolant.
The design with an induction heater is placed 800 mm from the ceiling, 300 from furniture and walls.
Installing a pressure gauge will secure your design.
It is desirable to equip the heating device with an automatic control system.
The heater must be connected to the mains with special adapters.

The principle of operation of an induction heater is based on two physical effects: the first is that when a conducting circuit moves in a magnetic field, an induced current appears in the conductor, and the second is based on the release of heat by the metals through which the current is passed. The first induction heater was implemented in 1900, when a method of non-contact heating of a conductor was found - for this, high-frequency currents were used, which were induced using an alternating magnetic field.

Induction heating has found application in various fields of human activity due to:

fast heating;
the ability to work in media of various physical properties (gas, liquid, vacuum);
no pollution by combustion products;
selective heating options;
shapes and sizes of the inductor - they can be any;
the possibility of process automation;
high percentage of efficiency - up to 99%;
environmental friendliness - no harmful emissions into the atmosphere;
long service life.

Scope of application: space heating

In everyday life, the induction heater circuit was implemented for and stoves. The former have gained especially great popularity and recognition among users due to the absence of heating elements, which reduce performance in boilers with a different operating principle, and detachable connections, which saves on maintenance of induction heating systems.

Note: The scheme of the device is so simple that it can be created at home, and you can create a home-made heater with your own hands.

In practice, several options are used, where different types of inductors are used:

electronically controlled heaters to create currents of the desired type in the coil;
vortex induction heaters.

Operating principle

The latter option, most commonly used in heating boilers, has become in demand due to the simplicity of its implementation. The principle of operation of the induction heating unit is based on the transfer of magnetic field energy to the coolant (water). The magnetic field is formed in the inductor. Alternating current, passing through the coil, creates eddy currents that transform energy into heat.

The water supplied through the lower pipe to the boiler is heated by energy transfer, and exits through the upper pipe, getting further into the heating system. A built-in pump is used to create pressure. Constantly circulating water in the boiler does not allow the elements to overheat. In addition, during operation, the heat carrier vibrates (at a low noise level), due to which scale deposits on the inner walls of the boiler are impossible.

Induction heaters can be implemented in various ways.

Implementation at home

Induction heating has not yet sufficiently conquered the market due to the high cost of the heating system itself. So, for example, for industrial enterprises, such a system will cost 100,000 rubles, for domestic use - from 25,000 rubles. and higher. Therefore, the interest in circuits that allow you to create a home-made induction heater with your own hands is quite understandable.

Transformer based

The main element of the induction heating system with a transformer will be the device itself, which has a primary and secondary windings. Vortex flows will form in the primary winding and create an electromagnetic induction field. This field will affect the secondary, which is, in fact, an induction heater, physically implemented in the form of a heating boiler body. It is the secondary short-circuited winding that transfers energy to the coolant.

The main elements of the induction heating installation are:

core;
winding;
two types of insulation - thermal and electrical insulation.

The core is two ferrimagnetic tubes of different diameters with a wall thickness of at least 10 mm, welded into each other. A toroidal winding of copper wire is made along the outer tube. It is necessary to impose from 85 to 100 turns with an equal distance between the turns. Alternating current, changing in time, creates vortex flows in a closed circuit, which heat the core, and hence the coolant, by induction heating.

Using high frequency welding inverter

An induction heater can be created using a welding inverter, where the main components of the circuit are an alternator, an inductor and a heating element.

The generator is used to convert the standard 50 Hz mains frequency into a higher frequency current. This modulated current is applied to a cylindrical inductor, where copper wire is used as a winding.

The coil creates an alternating magnetic field, the vector of which changes with the frequency set by the generator. The created eddy currents, induced by the magnetic field, heat the metal element, which transfers energy to the coolant. Thus, another do-it-yourself induction heating scheme is implemented.

A heating element can also be created with your own hands from a cut metal wire about 5 mm long and a piece of a polymer pipe into which the metal is placed. When installing valves at the top and bottom of the pipe, check the filling density - there should be no free space. According to the scheme, about 100 turns of copper wiring are superimposed on top of the pipe, which is the inductor connected to the generator terminals. Induction heating of copper wire occurs due to eddy currents generated by an alternating magnetic field.

Note: Do-it-yourself induction heaters can be made according to any scheme, the main thing to remember is that it is important to carry out reliable thermal insulation, otherwise the efficiency of the heating system will drop significantly.

Safety regulations

For heating systems that use induction heating, it is important to follow a few rules to avoid leaks, loss of efficiency, energy consumption, and accidents.

Induction heating systems require a safety valve to release water and steam in case the pump fails.
A manometer and an RCD are required for the safe operation of a do-it-yourself heating system.
The presence of grounding and electrical insulation of the entire induction heating system will prevent electric shock.
In order to avoid the harmful effects of the electromagnetic field on the human body, it is better to take such systems outside the residential area, where installation rules should be observed, according to which the induction heating device should be placed at a distance of 80 cm from horizontal (floor and ceiling) and 30 cm from vertical surfaces.
Before turning on the system, be sure to check the presence of the coolant.
To prevent malfunctions in the electrical network, it is recommended to connect a do-it-yourself induction heating boiler according to the proposed schemes to a separate supply line, the cable cross section of which will be at least 5 mm2. Ordinary wiring may not be able to withstand the required power consumption.

Diagram of a 500-watt induction heater that you can make yourself! There are many similar schemes on the Internet, but interest in them disappears, since basically they either do not work or work but not as we would like. This induction heater circuit is fully operational, proven, and most importantly, not complicated, I think you will appreciate it!

Components and Coil:

The working coil contains 5 turns, a copper tube with a diameter of about 1 cm was used for winding, but less is possible. This diameter was not chosen by chance, water is supplied through the tube to cool the coil and transistors.

Transistors set IRFP150 as IRFP250 was not at hand. Film capacitors 0.27 uF 160 volts, but you can put 0.33 uF and higher if you can’t find the first ones. Please note that the circuit can be powered with voltages up to 60 volts, but in this case, it is recommended to set the capacitors to 250 volts. If the circuit is powered by voltages up to 30 volts, then 150 is enough!

Zener diodes can be set to any 12-15 volts from 1 watt, for example 1N5349 and the like. Diodes can be used UF4007 and the like. Resistors 470 Ohm from 2 watts.

A few pictures:

Instead of radiators, copper plates were used, which are soldered directly to the tube, since water cooling is used in this design. In my opinion, this is the most efficient cooling, because the transistors heat up well and no fans and super radiators will save them from overheating!

The cooling plates on the board are arranged in such a way that the coil tube passes through them. The plates and the tube need to be soldered together, for this I used a gas burner and a large soldering iron for soldering car radiators.

The capacitors are located on a two-sided textolite, the board is also soldered to the coil tube in a straight line, for better cooling.

The inductors are wound on ferrite rings, I personally took them out of a computer power supply, the wire was used in copper insulation.

The induction heater turned out to be quite powerful, it melts brass and aluminum very easily, it also melts iron parts, but a little slower. Since I used IRFP150 transistors, according to the parameters, the circuit can be powered with voltage up to 30 volts, so the power is limited only by this factor. So all the same I advise you to use IRFP250.

That's all! Below I will leave a video of the operation of the induction heater and a list of parts that can be bought on AliExpress at a very low price!

Buy parts on Aliexpress:

Buy Transistors IRFP250
Buy Diodes UF4007
Buy Capacitors 0.33uf-275v

Hello site users radio circuits. Recently I had an idea to make a . Several schemes for building a device were found on the Internet. Of these, I chose the most, in my opinion, the easiest to assemble and configure, and most importantly - really working.

Device diagram

Parts list

1. Field effect transistor IRFZ44V 2 pcs.
2. Ultra fast diodes UF4007 or UF4001 2 pcs.
3. 470 Ohm resistor for 1 or 0.5 W 2 pcs.
4. Film capacitors
1) 1 uF for 250v 3 pcs.
2) 220 nF at 250v 4 pieces.
3) 470 nF at 250v
4) 330nF at 250v
5. Copper wire with a diameter of 1.2 mm.
6. Copper wire with a diameter of 2 mm.
7. Rings from the chokes of the computer power supply 2 pcs.

Device Assembly

The driving part of the heater is made on field-effect transistors IRFZ44V. Pinout transistor IRFZ44V.

Transistors need to be put on a large radiator. If you install transistors on one radiator, then the transistors must be installed on rubber gaskets and plastic washers so that there is no short circuit between the transistors.

The chokes are wound on rings from computer power supplies. Made from powdered iron. Wire 1.2 mm 7-15 turns.

The capacitor bank should be 4.7uF. It is advisable to use not one capacitor, but several capacitors. Capacitors must be connected in parallel.

The heater coil is made on a wire with a diameter of 2 mm 7-8 turns.

After assembly, the device works immediately. The device is powered by a 12 volt 7.2 A / h battery. The supply voltage of the device is 4.8-28 volts. During prolonged operation overheat: capacitor bank, field-effect transistors and chokes. Current consumption at idle 6-8 Amps.

When a metal object is introduced into the circuit, the current consumption immediately increases to 10-12 A.

Video of the operation of the induction heater

Then you can arrange the device in a suitable beautiful case and use it for various experiments. It is better to experiment with the power and size of the coil in order to achieve the best effect. Author of article 4ei3

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