A simple induction heater consists powerful generator high frequency and low-resistance coil-circuit, which is the load of the generator.
The 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 is placed in the center of this coil, then electromagnetic induction will occur inside it. As a result of frequent changes, this induction will cause eddy currents in the core, which in turn will lead to the generation of heat. This is the classical 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 materials.
I will show you a circuit diagram of a simple low-voltage induction heater, which has already become a classic.
We will simplify this circuit even more and we will not install the Zener diodes “D1, D2”.
Items you will need:
1. 10 kOhm resistors - 2 pcs.
2. 470 Ohm resistors - 2 pcs.
3. Schottky diodes for 1 A - 2 pcs. (Others are possible, the main thing is for a current of 1 A and high-speed)
4. Field-effect transistors IRF3205 - 2 pcs. (you can take any other powerful ones)
5. Inductor "5 + 5" - 10 turns with a tap from the middle. The thicker the wire, the better. I wound it on a wooden round stick, 3-4 centimeters in diameter.
6. Throttle - 25 turns on a ring from an old computer block.
7. Capacitor 0.47uF. It is better to gain capacity with several capacitors and for a voltage of at least 600 volts. At first I took it to 400, as a result of which it began to warm up, then I replaced it with a composite of two in series, but they don’t do that, they just didn’t have it at hand anymore.
Making a simple 12V induction heater
I assembled the entire circuit by surface mounting, separating the inductor from the entire circuit with a block. It is desirable to place the capacitor in the immediate vicinity of the coil terminals. Not like mine in this example in general. Transistors installed on radiators. Powered the entire installation from a 12 volt battery.
Works great. The blade of a clerical knife heats up to redness very quickly. I recommend everyone to repeat.
After replacing the capacitor, they no longer warmed up. The transistors and the inductor itself heat up if it is constantly running. For a short time - not critical almost.
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. Choke rings computer block 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 Idling 6-8 amps.
When a metal object is introduced into the circuit, the current consumption immediately increases to 10-12 A.
To heat up to red or even melt a small metal object at home, it is not at all necessary to fire up the stove and transfer fuel - modern technologies allow for this to use high-frequency currents (HF). And the simplest (and most common) circuit for an induction heater of metals will be a multivibrator based on field-effect transistors. At least these modules are assembled from Chinese sites. Next, see 2 models that differ in power and, of course, in price.
ZVS50- an entry-level induction heating module, the module can be powered even from batteries with a voltage of up to 12 volts, that is, from autonomous power supply, and from the network PSU. The price on www.banggood.com is about $8.
- Input voltage: 5-12V
- Board dimensions: 5.5 x 4 x 2 cm
- Coil size: length 2.8, diameter 2 cm
ZVS1000- a module for induction heating of metals by high frequency currents, with a power of up to 1000w. The average price is $35.
This induction heating unit uses a power supply direct current 12-48 V, maximum current 20 A, maximum power 1000 watts. Can be used to process small parts: hardening, annealing and other heat treatment. It can also be used with a crucible to melt gold, silver, copper, aluminum and other metals. Fast and uniform heating, which is very convenient for jewelers.
- Coil Inner Diameter: 40mm
- Coil Height: 50mm
- At 48 V no load current 5 A
The higher the voltage, the greater the heating current, and hence the power transmitted to the metal. The coil can accept inside 40 mm crucible. It is necessary to use the device with power supplies of the appropriate power and put a cooling cooler on the radiator.
The size of the object that is heated inside the induction coil cannot exceed 1/4 of the volume, otherwise overload and combustion of the circuit may occur. While this circuit can handle 30A temporarily - for long term operation the current should not exceed 20A for safe operation.
