Induction heater wiring diagram. How to make an induction heater with your own hands according to the diagram. Creation of sophisticated devices

Induction heating boilers- These are devices that are characterized by very high efficiency. They can significantly reduce energy costs compared to traditional devices equipped with heating elements.

Models industrial production not cheap. However, anyone can make an induction heater with their own hands. House master, owning a simple set of tools. We offer him help detailed description the operating principle and assembly of an effective heater.

Induction heating is impossible without the use of three main elements:

• inductor;
• generator;
• heating element.

An inductor is a coil, usually made of copper wire, that generates a magnetic field. An alternator is used to produce a high-frequency current from the standard 50 Hz household electrical current.

A metal object capable of absorbing energy is used as a heating element. thermal energy under influence magnetic field. If you connect these elements correctly, you can get a high-performance device that is perfect for heating coolant liquid and.

Using a generator, an electric current with the necessary characteristics is supplied to the inductor, i.e. onto a copper coil. When passing through it, a stream of charged particles forms a magnetic field.

The operating principle of induction heaters is based on the occurrence of electric currents inside conductors that appear under the influence of magnetic fields

The peculiarity of the field is that it has the ability to change the direction of electromagnetic waves at high frequencies. If any metal object is placed in this field, it will begin to heat up without direct contact with the inductor under the influence of the created eddy currents.

The high-frequency electric current supplied from the inverter to the induction coil creates a magnetic field with a constantly changing vector of magnetic waves. Metal placed in this field heats up quickly

The absence of contact makes it possible to make energy losses during the transition from one type to another negligible, which explains the increased efficiency of induction boilers.

To heat water for the heating circuit, it is enough to ensure its contact with a metal heater. Often a metal pipe is used as a heating element, through which a stream of water is simply passed. The water simultaneously cools the heater, which significantly increases its service life.

Electromagnet induction device produced by winding wire around a ferromagnet core. The resulting induction coil heats up and transfers heat to the heated body or the coolant flowing nearby through the heat exchanger

Advantages and disadvantages of the device

There are a great many “advantages” of a vortex induction heater. It's easy for self-made circuit, increased reliability, high efficiency, relatively low energy costs, long service life, low probability of breakdowns, etc.

The productivity of the device can be significant; units of this type are successfully used in metallurgical industry. In terms of heating rate of the coolant, devices of this type confidently compete with traditional ones. electric boilers, the water temperature in the system quickly reaches the required level.

During operation of the induction boiler, the heater vibrates slightly. This vibration shakes off the walls metal pipe limescale and other possible contaminants, so such a device rarely needs to be cleaned. Certainly, heating system should be protected from these contaminants using a mechanical filter.

An induction coil heats the metal (pipe or pieces of wire) placed inside it using high frequency eddy currents, no contact required

Constant contact with water minimizes the likelihood of the heater burning out, which is quite common problem for traditional boilers with heating elements. Despite the vibration, the boiler operates extremely quietly, additional sound insulation will not be needed at the installation location of the device.

Another good thing about induction boilers is that they almost never leak, unless the system is installed correctly. This is a very valuable quality for, as it eliminates or significantly reduces the likelihood of dangerous situations occurring.

The absence of leaks is due to the non-contact method of transferring thermal energy to the heater. Using the technology described above, the coolant can be heated almost to a vapor state.

This provides sufficient thermal convection to encourage efficient movement of coolant through the pipes. In most cases, the heating system will not have to be equipped circulation pump, although it all depends on the features and design of the specific heating system.

Conclusions and useful video on the topic

Video #1. Overview of induction heating principles:

Video #2. Interesting option making an induction heater:

To install an induction heater, you do not need to obtain permission from regulatory authorities; industrial models of such devices are quite safe, they are suitable for both a private home and ordinary apartment. But the owners homemade units Don't forget about safety precautions.

When a person is faced with the need to heat a metal object, fire always comes to mind. Fire is an old-fashioned, inefficient and slow way to heat metal. It spends the lion's share of energy on heat, and smoke always comes from the fire. How great it would be if all these problems could be avoided.

Today I will show you how to assemble an induction heater with your own hands with a ZVS driver. This device heats most metals using a ZVS driver and the power of electromagnetism. Such a heater is highly efficient, does not produce smoke, and heating such small metal products as, say, a paper clip is a matter of a few seconds. The video shows the heater in action, but the instructions are different.

Step 1: Operating principle

Many of you are now wondering – what is this ZVS driver? This is a highly efficient transformer capable of creating a powerful electromagnetic field that heats the metal, the basis of our heater.

To make it clear how our device works, I will talk about key points. First important point— 24 V power supply. The voltage should be 24 V with a maximum current of 10 A. I will have two lead acid batteries connected in series. They power the ZVS driver board. The transformer supplies a steady current to the coil, inside which the object to be heated is placed. Constantly changing the direction of the current creates an alternating magnetic field. It creates eddy currents inside the metal, mainly of high frequency. Due to these currents and the low resistance of the metal, heat is generated. According to Ohm's law, the current strength transformed into heat in a circuit with active resistance will be P=I^2*R.

The metal that makes up the object you want to heat is very important. Iron-based alloys have higher magnetic permeability and can use more magnetic field energy. Because of this, they heat up faster. Aluminum has low magnetic permeability and therefore takes longer to heat up. And objects with high resistance and low magnetic permeability, such as a finger, will not heat up at all. The resistance of the material is very important. The higher the resistance, the weaker the current will pass through the material, and the correspondingly less heat will be generated. The lower the resistance, the stronger the current will be, and according to Ohm's law, the less voltage loss. It's a little complicated, but due to the relationship between resistance and power output, maximum power output is achieved when resistance is 0.

The ZVS transformer is the most complex part of the device, I will explain how it works. When the current is turned on, it flows through two induction chokes to both ends of the coil. Chokes are needed to ensure that the device does not produce too much current. Next, the current flows through 2 470 Ohm resistors to the gates of the MOS transistors.

Due to the fact that there are no ideal components, one transistor will turn on before the other. When this happens, it takes over all the incoming current from the second transistor. He will also short the second one to the ground. Because of this, not only will current flow through the coil to the ground, but also through the fast diode the gate of the second transistor will discharge, thereby blocking it. Due to the fact that a capacitor is connected in parallel to the coil, an oscillatory circuit is created. Due to the resulting resonance, the current will change its direction and the voltage will drop to 0V. At this moment, the gate of the first transistor discharges through the diode to the gate of the second transistor, blocking it. This cycle repeats thousands of times per second.

The 10K resistor is supposed to reduce excess gate charge on the transistor by acting as a capacitor, and the Zener diode is supposed to keep the transistors' gate voltage at 12V or lower to keep them from blowing up. This transformer is a high frequency voltage converter that allows metal objects to heat up.
It's time to assemble the heater.

Step 2: Materials

To assemble a heater, you need few materials, and most of them, fortunately, can be found for free. If you see a cathode ray tube lying around somewhere, go and pick it up. It contains most of the parts needed for the heater. If you want higher quality parts, buy them from an electrical parts store.

You will need:

Step 3: Tools

For this project you will need:

Step 4: Cooling the FETs

In this device, the transistors turn off at a voltage of 0 V and do not heat up very much. But if you want the heater to run longer than one minute, you need to remove heat from the transistors. I made one common heat sink for both transistors. Make sure that the metal gates do not touch the absorber, otherwise the MOS transistors will short out and explode. I used a computer heatsink and it already had a stripe on it silicone sealant. To check the insulation, touch the middle leg of each MOS transistor (gate) with a multimeter; if the multimeter beeps, then the transistors are not isolated.

Step 5: Capacitor Bank

Capacitors become very hot due to the current constantly passing through them. Our heater needs a capacitor value of 0.47 µF. Therefore, we need to combine all the capacitors into a block, this way we will get the required capacitance and the heat dissipation area will increase. The capacitor voltage rating must be higher than 400 V to account for inductive voltage peaks in the resonant circuit. I made two rings of copper wire, to which I soldered 10 0.047 uF capacitors in parallel to each other. Thus, I received a capacitor bank with a total capacity of 0.47 µF with excellent air cooling. I will install it parallel to the working spiral.

Step 6: Working Spiral

This is the part of the device in which the magnetic field is created. The spiral is made of copper wire - it is very important that copper is used. At first I used a steel coil for heating, and the device did not work very well. Without workload it consumed 14 A! For comparison, after replacing the coil with a copper one, the device began to consume only 3 A. I think that eddy currents arose in the steel coil due to the iron content, and it was also subject to induction heating. I'm not sure if this is the reason, but this explanation seems to me the most logical.

For the spiral, take large-gauge copper wire and make 9 turns on a piece of PVC pipe.

Step 7: Chain Assembly

I did a lot of trial and error until I got the chain right. The biggest difficulties were with the power source and the coil. I took a 55A 12V switching power supply. I think this power supply supplied too high an initial current to the ZVS driver, causing the MOS transistors to explode. Perhaps additional inductors would have fixed this, but I decided to simply replace the power supply with lead-acid batteries.
Then I struggled with the reel. As I already said, the steel coil was not suitable. Due to the high current consumption of the steel coil, several more transistors exploded. In total, 6 transistors exploded. Well, they learn from mistakes.

I have rebuilt the heater many times, but here I will tell you how I assembled the best version of it.

Step 8: Assembling the device

To assemble the ZVS driver, you need to follow the attached diagram. First I took a Zener diode and connected it to a 10K resistor. This pair of parts can be immediately soldered between the drain and source of the MOS transistor. Make sure the Zener diode is facing the drain. Then solder the MOS transistors to the breadboard with contact holes. On the bottom side breadboard Solder two fast diodes between the gate and drain of each transistor.

Make sure the white line is facing the shutter (Fig. 2). Then connect the positive from your power supply to the drains of both transistors through a 2,220 ohm resistor. Ground both sources. Solder the working coil and the capacitor bank parallel to each other, then solder each end to a different gate. Finally, apply current to the gates of the transistors through 2 50 μH inductors. They may have a toroidal core with 10 turns of wire. Your circuit is now ready to use.

Step 9: Mounting to Base

In order for all the parts of your induction heater to hold together, they need a base. I took it for this wooden block A 5*10 cm board with an electrical circuit, a capacitor bank and a working coil were glued with hot melt adhesive. I think the unit looks cool.

Step 10: Functionality Check

To turn your heater on, simply connect it to a power source. Then place the item you need to heat in the middle of the working coil. It should start to heat up. My heater heated the paperclip to a red glow in 10 seconds. Objects larger than nails took about 30 seconds to heat up. During the heating process, the current consumption increased by approximately 2 A. This heater can be used for more than just entertainment.

After use, the device does not produce soot or smoke, it even affects isolated metal objects, for example, gas absorbers in vacuum tubes. The device is also safe for humans - nothing will happen to your finger if you place it in the center of the working spiral. However, you can get burned by an object that has been heated.

Thank you for reading!

Hi all. Today we’ll look at a popular item - an induction heater straight from China, or rather from the Benggood store.

The Chinese produce such boards with different modifications, to suit every taste.

My sample is not one of the most budget-friendly, it comes with an inductor, nowadays it is quite difficult to get a copper pipe of the required diameter, so if you take such a board, it is better to go with an inductor.

So, this is a popular ZVS driver circuit, on the basis of which you can build anything, from simple converters to induction heaters. I intend to test this sample in detail, reveal its potential, and make all possible measurements, so we will not limit ourselves to one article.

The kit includes the board and the inductor itself, the heater circuit is now in front of you.

The declared power is 1 kilowatt, the input voltage is from 12 to 36 Volts with a maximum current of 20 Amps, here the Chinese are refuting themselves, because even at the maximum voltage and current the power consumption will be no more than 720 watts, but knowing this circuit, I will say that it can be powered and from higher voltages, up to 60 volts and consume currents of more than 20 Amperes, so that if we are talking about power consumption, then it can exceed 1000 watts, but the Chinese are silent about the useful power, taking into account the efficiency of the circuit. In reality, the useful power is about 200-250 watts when powered from a 36V source.

The printed circuit board is double-sided, made perfectly, but the Chinese were a little too lazy to clean the remaining flux, the manufacturer additionally tinned the power traces, in general, there are no complaints, you can now see the dimensions of the board on your screens. (Later, when 36 Volts were supplied, after some time one of the power tracks simply burned out, we had to reinforce it with multi-core copper wire and tin everything additionally)

The circuit has forced cooling in the form of a cooler, it is located directly above the transistors and is powered by a separate step-down stabilizer based on the XL2596 chip. The stabilizer board is glued to the cooler with snot (hot).

There are 2 power transistors, these are powerful field switches IRFP260 (200V 50A), and the circuit is a push-pull self-oscillator.

To limit the current of the switch gates, powerful 470 Ohm resistors are used; they look like two-watt resistors, but the sizes are slightly larger than standard two-watt resistors, so that resistors of 3 or 4 watts are possible.

Resistors are at the same time limiters for zener diodes, which prevent the formation of increased voltage at the gate of the switches, stabilizing at a level of 12 Volts; a seat for a linear stabilizer of 12 or 15 volts is visible, since zener diodes in some versions are replaced with a linear stabilizer.

An inductor with a bank of capacitors form a parallel oscillatory circuit; the parameters of these components set the operating frequency of the circuit as a whole, since this is a resonant converter.

The battery consists of 6 specialized capacitors, each capacitance is 0.33 µF, the total capacity is about 2 µF.

Such capacitors are designed for operation in high-frequency circuits and are used in particular in induction heaters, so that this perfect option for such a scheme.

The board has brass stands for mounting the cooler and inductor, a rather convenient solution.

There are two chokes, power supply is supplied through them, both chokes are identical, wound on rings made of powdered iron. Number of turns 30, wire diameter 1 mm, inductance 74 μH.

The inductor or circuit is a copper pipe with a diameter of 5 mm, the internal diameter of the inductor is 42 mm, the number of turns is almost 8, the turns can be stretched or compressed, the main thing is not to short-circuit.

Power is supplied to the terminal block, which is located in a secluded place under the cooler.

The same terminal block is also available at the front; a circuit can be connected to it. This terminal block is convenient when using circuits made of copper wire.

The polarity is marked on the power terminals, there will be no problems with connection.

I think everything is clear with the board, let's move on to tests. I want to say right away that I will fully load the inductor in one of the following articles, since maximum overclocking requires water cooling, and, unfortunately, I do not have the appropriate water pump.

So, first of all, let's check the no-load current from a 12-volt source.

As you can see, the circuit consumes about 2 Amperes; I will say that for this particular circuit, such consumption is the norm.

From a 24 Volt source, consumption increased to 4 A, which was to be expected.

And finally, from a 36 Volt source, the circuit consumes almost 5.5A at idle.

The operating frequency is about 90KHz,

This is the shape of the pulses on the gate of one of the keys.

We see a pure sinusoid on the inductor, pay attention to the amplitude swing, which is many times higher than the supply voltage.

For testing, 3 completely new 12 Volt batteries from an uninterruptible power supply were purchased, connected in series to obtain 36 Volts.
In a couple of seconds, you can heat up thin sheet metal similar to the blades of office knives, etc.

Now you see the consumption of the circuit in the case of heating the tin sleeve from the 18650 battery, the battery voltage dropped to 26 Volts.

Without a fan, everything heats up - switches, chokes, capacitors and gate resistors, the circuit heats up especially critically even without a load, that’s why it is in the form of a pipe and if you are going to use the heater for some purpose, be sure to let in water cooling, otherwise the circuit will literally become red hot. I also highly recommend strengthening the power buses on the board, the Chinese have tinned them, but they heat up terribly.

Readers may have a completely normal question: will such an induction heater heat metals other than iron? I will say that it heats, but so weakly that it is almost imperceptible. I tried aluminum, brass, copper, tin, the heating is barely felt, but despite this, it will be possible to melt some metals with such an inductor if the crucible is installed in iron pipe, A better pipe into the crucible, the iron will heat up and the heat will be transferred to the metal that is to be melted.

In any case, you need to remember that the circuit is amateurish and is not suitable for serious purposes due to the lack of a PWM control circuit, current control, temperature control, protections and other components that are contained in expensive, professional heaters, but professional models can cost several hundred thousand rubles , and our scarf costs only some 36 evergreen dollars.

In case of operation, I advise you to install a 40 Ampere power supply fuse so as not to burn the keys in case of emergency, and this is easy to do if you accidentally close the circuit turns at high supply voltages, or reverse the polarity of the power supply.
That's all for today, subscribe to our group so as not to miss updates.

The product can be purchased

Video review

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 a metal cookware, 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.

Expensive ceramics are used in household induction hobs; when manufactured 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

To make a stove you will need the 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 aluminum alloy radiators are not attached to them, 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, screw a copper tube onto a rod with flat surface 4 cm in diameter. The spiral must have 7 turns, which should not touch. The 2 ends of the tube are soldered fastening rings for connection to 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 pipe from of stainless steel with a diameter of 20 mm. 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. When 4 such devices are turned on simultaneously, 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 of 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 a stainless pipe, the heated water will rise upward, and a colder liquid will take its place.
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 at 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 the installation of rechargeable batteries to power the induction devices, the charging of which will be carried out 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, therefore the induction boiler should be installed in non-residential premises 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 constantly operate this device due to the imperfection of the self-manufactured shielding of this device; because of this, the human body may be exposed to harmful electromagnetic radiation that can negatively affect health.

A simple induction heater consists of powerful generator high frequency and low-resistance coil-circuit, which is the load of the generator.

A self-excited generator generates pulses based on the resonant frequency of the circuit. As a result, a powerful alternating electromagnetic field with a frequency of about 35 kHz appears in the coil.
If a core of conductive material, then inside it will arise electromagnetic induction. As a result of frequent changes, this induction will cause eddy currents in the core, which in turn will lead to the release of heat. This is the classic principle of converting electromagnetic energy into thermal energy.
Induction heaters have been used for a very long time in many areas of production. With their help, you can do hardening, non-contact welding, and most importantly, spot heating, as well as melting of materials.
I'll show you the circuit of a simple low-voltage induction heater, which has already become a classic.

Making a simple 12V induction heater