Inverter 12 - 220V with a power of 500 Watt: do it yourself: diagram and detailed description manufacturing.
Diagram of a voltage converter (inverter) from 12 to 220 volts, for operating household appliances from a 12V battery.
The circuit is assembled on two 155 series microcircuits and six transistors. The output stage uses field-effect transistors that have a very low on-resistance, which increases the efficiency of the converter and eliminates the need to install them on radiators that are too large.
On the D1 chip, a rectangular pulse generator is assembled, the repetition rate of which is about 200 Hz - diagram “A”. From pin 8 of the microcircuit, pulses are sent further to frequency dividers assembled on elements D2.1 - D2.2 of microcircuit D2. As a result, at pin 6 of the D2 chip, the pulse repetition rate becomes half as much - 100 Hz - diagram “B”, and at pin 8 the pulses become equal to the frequency of 50 Hz - diagram “C”. Non-invertible 50 Hz pulses are removed from pin 9 - diagram “D”.
Built on diodes VD1-VD2 logic circuit"OR". As a result, the pulses taken from the pins of microcircuits D1 pin 8, D2 pin 6 form a pulse corresponding to diagram “E” at the cathodes of the diodes. The cascade on transistors V1 and V2 serves to increase the amplitude of the pulses necessary to fully open the field-effect transistors. Transistors V3 and V4 connected to outputs 8 and 9 of microcircuit D2 open alternately, thereby locking either one field-effect transistor V5 or another V6.
As a result, control pulses are formed in such a way that there is a pause between them, which eliminates the possibility of through current flowing through the output transistors and significantly increases efficiency. Diagrams “F” and “G” show the generated control pulses for transistors V5 and V6.
A correctly assembled converter starts working immediately after power is applied. When setting up, you should connect a frequency meter to the output of the device and set the frequency to 50-60 Hz by selecting resistor R1, and, if necessary, capacitor C1.
Transistors KT315 with any letter index, KT209 can be replaced with KT361 with any letter index. We will replace the KA7805 voltage stabilizer with the domestic KR142EN5A. Any resistors with a power of 0.125…0.25 W. Almost any low-frequency diodes, for example KD105, IN4002.
Capacitor C1 type K73-11, K10-17V with low capacity loss when warming up. The transformer was taken from an old tube black and white TV, for example: “Spring”, “Record”. The 220 volt winding remains, and the remaining windings are removed. Two windings are wound on top of this winding with PEL wire - 2.1 mm. For better symmetry, they should be wound simultaneously into two wires. When connecting the windings, take into account the phasing.
Field-effect transistors are fixed through mica spacers to a common aluminum radiator with a surface area of at least 600 sq.cm.
There are several reasons why the owner needs to create a new voltage converter. Its main purpose is to provide a mains voltage of 220V from the original value of 12 W.
Many amateurs make 12-220 V inverters with their own hands, because... High-quality converters are not cheap. Before assembling the device, it is necessary to study materials explaining the mechanism of its use.
Scope of application of converters 12-220 V
As the battery operates, its charge level decreases. The converter stabilizes the voltage during travel, in the absence of electricity.
A 12-220 V inverter will allow the owner to improve the engineering structures in the house. The power of the device for converting current is selected depending on the total size of the load being used. The process of its consumption is taken into account: reactive and active. The reactive load does not consume all the energy received, so the apparent power exceeds its active value.
A pure sine wave inverter is used to power tools with a total power of 3kW. Significant fuel savings are ensured by the use of a voltage converter and a mini-power station.
The following consumers are connected to the inverter:
- alarm systems;
- heating boilers;
- pumping devices;
- computer systems.
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Advantages of operating a voltage conversion device
Inverters have won a respectful attitude towards their work, because they have a number of undoubted advantages. The device operates silently and does not pollute the surrounding space with exhaust gases. Maintenance of the device is minimal: there is no need to check the pressure in the engine. The inverter has minor mechanical wear and allows you to connect any consumers. The 12-220 V inverter operates at increased power on the KR121 EU and has a high efficiency.
When assembling an inverter with a master device as a multivibrator, the advantages of the converter are expressed in the accessibility and simplicity of the device. The dimensions of the product are compact, repair is not difficult, and operation is possible at low temperatures.
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Homemade 12-220 V converter and the general principle of its creation
In the radio components market most inverters operate using high frequencies. Switching inverters have been completely replaced classic schemes using transformers. The K561TM2 microcircuit consists of two D-flip-flops, which contain two inputs R and S. It is created using CMOS technology and enclosed in a plastic housing.
The inverter master oscillator is mounted on the basis of K561TM2, using the DD1 device for operation. A DD1.2 trigger is mounted for the frequency divider. The amplifier stage receives signals from the microcircuit.
KT827 transistors are selected for operation. In their absence, use KT819 GM transistors or field-effect semiconductors - IRFZ44.
The sine wave generator for the 12-220 V inverter operates at high frequency. To form a circuit with dimensions of 50 Hz, a secondary winding and parallel connection of a capacitor and load are used. When connecting any device, the inverter creates a voltage conversion of 220 V.
The circuit has one significant drawback - the imperfect form of the output parameters.
The K561TM2 microcircuit is duplicated by the K564TM2. An increase in converter power is achieved by selecting more intense transistors. You should pay attention to the capacitor installed at the output. It has a voltage of 250 V.
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Building a converter using the latest parts
Homemade inverters operate stably; the output transistors operate from an amplified main generator. They use elements of the KT819GM series, installed on a large radiator.
To create a converter, a simplified circuit is used. In the process of work, acquire the necessary materials:
- microcircuit KR121EU1;
- transistors IRL2505;
- soldering iron;
- tin.
The KR12116U1 microcircuit has a special feature: it contains two channels for adjusting the keys and can easily cope with the construction of simple voltage converters. The microcircuit at a temperature of +25 °C produces maximum voltage values of 3 and 9 V.
The frequency of the master oscillator is determined by the parameters of the elements in the circuit. IRL2505 transistors are installed for output use. It receives a signal, the level of which allows you to adjust the output transistors.
The formed low level does not allow the transistors to move from the closed state to another state. As a result, the occurrence of instantaneous current flow after the simultaneous opening of the keys is completely eliminated. When a high level hits pin 1, pulse generation is turned off. In the diagram, pin 1 is connected to the common wire.
To install a push-pull cascade, transformer T1 and two transistors are used: VT1 and VT2. In the open channel, a resistance of 0.008 Ohm is observed. It is insignificant, so the power of the transistors is small, even when a large current passes. The output transformer, which has a power of 100 W, allows the IRL2505 to use up to 104 A current, and the pulse current is 360 A.
The main feature of the inverter is that you can use any transformer that has 2 12 V windings at the output.
With an output power of up to 200 W, they refuse to install transistors on radiators.
It should be noted that the electric current at a power of 400 W can reach 40 A.
When using low-power household appliances, there is often a need for a voltage converter from 12 to 220 volts. This could be a laptop, a charger for a mobile phone or tablet, or even a TV with LED elements.
In what cases is a voltage converter needed?
- Long-term failure of centralized power supply.
- Emergency power supply for gas boiler electronics.
- Lack of 220 volt household network (remote garden plot, garage cooperative).
- Automobile.
- Tourist parking (if possible, take a 12 volt battery with you).
In all these cases, it is enough to have a charged battery, and you will be able to fully use the network electrical equipment.
Please note
Important! The power consumption of the device should not exceed several hundred watts. More powerful devices will quickly drain the battery used as a donor.
To be fair, we note that for use in a car there are power supplies and chargers, connected to the on-board 12 volt network. They are made in the form of a connector connected to the cigarette lighter socket.
However, if you have several gadgets, you will have to splurge on buying the same number of chargers. And having one converter from 12 to 220, you will ensure complete connection versatility.
There is a wide range of ready-made converters available for sale. Power varies from 150 W to several kilowatts. Of course, for each consumer power it is necessary to select the appropriate battery.
You should also read carefully technical specifications– often, for advertising purposes, manufacturers indicate on the packaging the peak power that the converter can withstand for just a few seconds. Operating power is typically 25% – 30% lower.
Types of converters 12 to 220 volts
For the right choice, familiarize yourself with the main types of voltage converters presented on the electrical goods market:
According to the output voltage waveform
The devices are divided into pure sine and modified sine. The difference in signal shape can be seen in the illustration.
In this article you can find detailed information step by step instructions for the manufacture of an AC inverter for 220 V 50 Hz from a 12 V car battery. Such a device is capable of delivering power from 150 to 300 W.
The circuit diagram of this device is quite simple..
This circuit operates on the principle of Push-Pull converters. The heart of the device will be the CD-4047 board, which operates as a master oscillator and also controls field-effect transistors that operate in switch mode. Just one transistor can be open; if two transistors are open at the same time, a short circuit will occur, as a result of which the transistors will burn out; this can also happen in case of improper control.
The CD-4047 board is not designed for high-precision control of field-effect transistors, but it copes with this task perfectly. Also, for the device to operate, you will need a transformer from an old 250 or 300 W UPS with a primary winding and a middle positive connection point from the power source.
The transformer has enough large number secondary windings, you will need to use a volt-ohmmeter to measure all taps and find a 220V network winding. The wires we need will give the highest electrical resistance of approximately 17 ohms, you can remove the extra leads.
Before you start soldering, it is advisable to double-check everything again. It is recommended to select transistors from the same batch and with the same characteristics; the capacitor of the driving circuit often has a small leakage and a narrow tolerance. Such characteristics are determined by a transistor tester.
Since the CD-4047 board has no analogues, you need to purchase it, but if necessary, you can replace the field-effect transistors with n-channel ones with a voltage of 60V or more and a current of at least 35A. Suitable from the IRFZ series.
The circuit can also operate using bipolar transistors at the output, but it should be noted that the power of the device will be much less when compared with a circuit that uses “field switches”.
Limiting gate resistors should have a resistance of 10-100 ohms, but it is preferable to use 22-47 ohm resistors with a power of 250 mW.
Often the master circuit is assembled exclusively from the elements indicated in the diagram, which has precise settings at 50 Hz.
If you assemble the device correctly, it will work from the first seconds, but when starting it for the first time, it is important to be on the safe side. To do this, instead of a fuse (see diagram), you need to install a resistor with a nominal value of 5-10 Ohms or a 12V light bulb, in order to avoid the transistors exploding if mistakes were made.
If the device operates stably, the transformer will make a sound, but the keys will not heat up. If everything works correctly, the resistor (bulb) needs to be removed, and power is supplied through the fuse.
On average, the inverter consumes energy when the robot is idling from 150 to 300 mA, depending on the power source and the type of transformer.
Then you need to measure the output voltage, the output should be about 210-260V, this is considered a normal indicator, since the inverter does not have stabilization. Next, you need to check the device by connecting a 60-watt light bulb under load and letting it work for 10-15 seconds; during this time the keys will heat up a little, since they do not have heat sinks. The keys should heat up evenly; if the heating is not uniform, you need to look for where errors were made.
We equip the inverter with the Remote Control function
The main positive wire should be connected to the middle point of the transformer, but for the device to start working, a low-current positive must be connected to the board. This will start the pulse generator.
A couple of suggestions about installation. Everything is installed in the computer power supply case; the transistors should be installed on separate radiators.
If a common heat sink is installed, be sure to isolate the transistor housing from the heatsink. The cooler is connected to a 12V bus.
One of the significant disadvantages of this inverter is the lack of short circuit protection and if it occurs, all transistors will burn out. In order to prevent this, you must install a 1A fuse at the output.
To start the inverter, a low-power button is used, through which plus will be supplied to the board. The power busbars of the transformer should be fixed directly to the radiators of the transistors.
If you connect an energy meter to the output of the converter, you will be able to see that the outgoing frequency and voltage are within the permissible limits. If you get a value greater or less than 50Hz, you need to adjust it using a multi-turn variable resistor, it is installed on the board.
Such an inverter is designed to produce alternating current 220 V 50 Hz from a car battery or any 12 V battery. The inverter power is about 150 W and can be increased to 300.
The circuit operates as a Push-Pull converter. The heart of the inverter is the CD4047 chip, which acts as a master oscillator and simultaneously controls field-effect transistors. The latter operate in key mode. Only one of the transistors can be open. If both transistors open at the same time, a short circuit will occur and the transistors will burn out instantly. This can happen due to improper management.
The CD4047 chip, of course, is not designed for high-precision control of field workers, but it copes with this task quite well.
The transformer was taken from a non-working UPS. It is 250-300 W and has a primary winding with a middle point where the plus from the power source is connected.
There are many secondary windings, so you need to find a 220 V network winding. Using a multimeter, the resistance of all taps that are on the secondary circuit is measured. The required leads should have the highest resistance (in the example, about 17 Ohms). All other wires can be bitten off.
It is recommended to check all components before soldering. It is better to select transistors from the same batch with similar characteristics. The capacitor in the frequency-setting circuit must have low leakage and a narrow tolerance. These parameters can be checked with a transistor tester.
A few words about possible replacements in the scheme. Unfortunately, the CD4047 chip has no Soviet analogues, so you need to buy it. “Field switches” can be replaced with any n-channel transistors that have a voltage of 60 V and a current of 35 A. Suitable from the IRFZ line.
The circuit also works great with bipolar transistors at the output, although the power will be much lower than when using field-effect transistors.
Gate limiting resistors can have a resistance of 10 to 100 ohms. It is better to set from 22 to 47 Ohms with a power of 250 mW.
The frequency-setting circuit must be assembled only from those elements indicated in the diagram. It will be finely tuned to 50 Hz.
A correctly assembled device should work immediately. But the first launch must be done with insurance. That is, in place of the fuse according to the diagram, install a resistor with a nominal value of 5-10 Ohms, or a 12 V (5 W) lamp, so as not to blow up the transistors if problems arise.
If the converter is working normally, the transformer makes a sound, and the keys should not heat up at all. If this is the case, then the resistor can be removed and power supplied directly through the fuse.
The average current consumption of an inverter at idle can be between 150 and 300 mA, but this will depend on the power supply and the transformer used.
Next, the output voltage is measured. In the example, the values were from 210 to 260 V. This is within normal limits, since the inverter is not stabilized. Now you can turn on the load, for example, a 60 W lamp. You need to drive the inverter for about 10 seconds, the keys should heat up a little, since they do not yet have heat sinks. The heating on both keys should be uniform. If this is not the case, then look for jambs.
The inverter is equipped with a Remote Control function.
The main power plus is connected to the midpoint of the transformer. But for the inverter to work, it is necessary to apply a low-current plus to the board. This will start the pulse generator.
A few words about installation. As always, everything fits well in the computer's power supply case. The transistors are installed on separate radiators.
If a common heat sink is used, it is necessary to isolate the transistor housings from the radiator. The cooler was connected directly to the 12 V bus.
The biggest drawback of this inverter is the lack of short circuit protection. In this case, the transistors will burn out. To prevent this from happening, a 1 A fuse is needed at the output.
A low-power button supplies plus from the power source to the board, that is, it starts the inverter as a whole.
Power busbars from the transformer are attached directly to the radiators of the transistors.
By connecting a device called an energy meter to the output of the converter, you can make sure that the voltage and frequency are within normal limits. If the frequency differs from 50 Hz, then it must be adjusted using a multi-turn variable resistor, which is present on the board.
During operation, when no load is connected to the output, the transformer is quite noisy. When the load is connected, the noise is negligible. This is all normal, since rectangular pulses are supplied to the transformer.
The resulting inverter is unstabilized, but almost all household appliances are adapted to operate in the voltage range from 90 to 280 V.
If the output voltage is higher than 300 V, then it is recommended to connect a 25-watt incandescent light bulb to the output in addition to the main load. This will reduce the output voltage to a small extent.
In principle, it is possible to power commutator motors from a converter, but they heat up 2 times more than when powered from a pure sine wave.
The same thing happens with consumers that have an iron transformer. But asynchronous motors It is not recommended to connect.
The weight of the device is about 2.7 kg. This is a lot when compared with pulse inverters.
Attached files:
How to make a simple Power Bank with your own hands: diagram of a homemade power bank
