Norms

Let's try to make a voltage converter ourselves. Voltage converter Converter from 12V to 220V

When it is necessary to create mains voltage in a car, special 12-220 converters are usually used. There are inexpensive standard inverters on sale for about 20-30 dollars. However, the maximum power of such devices is, at best, about 300 watts. In some cases, this power may not be enough.

You can get power for a powerful amplifier through small transformations. It is enough just to replace the secondary winding on a standard inverter. After this, you can get any value of the input voltage. For example, the power of a 400 Watt inverter will increase to 600 Watts.

To increase power at home, experts recommend using a simple method. It will be necessary to replace the high-power bipolar switches with IRF 3205.

An inverter is used for operation, to which it is possible to connect 4 pairs of output transistors. Therefore, the device, after carrying out the necessary work, will be able to produce a power of about 1300 watts. If you buy a ready-made inverter with such parameters, its cost will increase to 100-130 dollars.

It is worth noting that the traditional push-pull circuit of the device does not contain protection against overheating, short circuit and output overloads.

The generator is based on a TL 494 microchip, which has an additional driver. It is necessary to replace low-power bipolar transistors with domestic analogues (KT 3107).

In order not to use powerful switches to supply power, the inverter is equipped with a remote control circuit.

In the driving part of the device, special SCHOTTTKI diodes type 4148 are used (domestic KD 522 is also suitable). The transistor in the remote control circuit is replaced with KT 3102.

After this, you can move on to the most important part of the project - the transformer. This element is wound on a pair of glued 3000 NM rings. Moreover, the size of each of them is 45x28x8. For a tighter fixation, the rings can be wrapped with tape.

Then the rings are wrapped on top with fiberglass (the cost in the store is no more than $1). It is quite acceptable to replace this material with fabric electrical tape.

Fiberglass is cut into small strips about 2 cm wide and no more than 50 cm long. The material for work has high heat resistance, and thanks to the thin base, the insulation looks neat.

For the primary winding you need 2x5 turns of wire, that is, 10 turns with a tap from the middle. The work is carried out with a wire with a diameter of 0.7-0.8 mm, and 12 wires are used for each arm. The process is presented more clearly in the following photographs.

The tourniquet is stretched, and 5 turns are evenly wound on both arms, stretching them across the entire ring. The windings must be the same.

The resulting elements have four outputs. The beginning of the first winding must be soldered to the end of the second. The solder location will be a tap for a power voltage of 12 V.

At the next stage of work, the ring must be insulated with fiberglass and covered with a secondary winding.

The secondary winding increases the output voltage. Therefore, when carrying out work you need to be as careful as possible and follow all safety precautions. It is worth remembering that high voltage is dangerous. Installation of the device is carried out only with the power turned off.

The winding of the rings is carried out using a pair of parallel strands of 0.7-0.8 mm wire. The number of turns is about 80 pieces. The wire is distributed evenly throughout the ring. At the final stage, the product is additionally insulated with fiberglass.

When the inverter assembly is completed, you can begin testing it. The device is connected to a battery; for starters, a battery with a voltage of 12 V from an uninterruptible power supply will do. In this case, the “plus” of power will go to the circuit through a 100-watt halogen lamp. It is worth paying attention that this lamp should not be lit before or during work.

After this, you can proceed to checking the field keys for heat generation. With a correctly assembled circuit, it should be practically zero. If there is no input load, and the transistors overheat, then you need to look for a non-working component in the device.

If the testing is successful, you can install the transistors on one common heat sink. For this purpose, special insulating gaskets are used.

The circuit diagram in *.lay format is in the archive file and will be available after downloading.

Lately I have often observed that more and more people are getting carried away with assembling homemade inverters. Since novice radio amateurs are interested, I decided to recall the diagram that I published on our website a year ago. Today I decided to remake the circuit increasing the output power and explain the assembly process in detail.

I’ll say right away - this is the simplest 12-220 converter, taking into account the output power of the circuit. The good old multivibrator is used as a master oscillator. Of course, this solution is much inferior to modern high-precision generators on microcircuits, but let's not forget that I tried to simplify the circuit as much as possible so that the result would be an inverter that would be available to the general public. A multivibrator is not bad, it works more reliably than some microcircuits, is not so critical to input voltages, and works in harsh weather conditions (remember the TL494, which needs to be heated at sub-zero temperatures).

The transformer used is a ready-made one from UPS; the core dimensions allow for 300 watts of output power. The transformer has two primary windings of 7 Volts (each arm) and a mains winding of 220 Volts. In theory, any transformers from uninterruptible power supplies will do.

The diameter of the primary winding wire is about 2.5 mm, just what is needed.

Main characteristics of the circuit

Input voltage rating - 3.5-18 Volts
Output voltage 220V +/-10%
Output frequency - 57 Hz
Output pulse shape - Rectangular
Maximum power - 250-300 Watts.

Flaws

I thought for a long time about the shortcomings of the circuit, regarding the efficiency, it is 5-10% lower than similar industrial devices.
The circuit does not have any protection at the input or output; in the event of a short circuit or overload, the field switches will overheat until they fail.
Due to the shape of the pulses, the transformer makes some noise, but this is quite normal for such circuits.

Advantages

Simplicity, accessibility, costs, 50 Hz output, compact board sizes, easy repairs, the ability to work in harsh weather conditions, wide tolerance of the components used - all these advantages make the circuit universal and accessible for independent repetition.

A Chinese inverter for 250-300 watts can be bought for about $30-40, I spent $5 on this inverter - I bought only field-effect transistors, everything else can be found in the attic, I think everyone has it.

Element base

The harness has a minimum number of components. IRFZ44 transistors can be successfully replaced with IRFZ40/46/48 or more powerful ones - IRF3205/IRL3705, they are not critical.

Multivibrator transistors TIP41 (KT819) can be replaced with KT805, KT815, KT817, etc.

I successfully connected a TV, a vacuum cleaner and other household devices to this inverter, it works well, if the device has a built-in switching power supply, then you will not notice the difference in operation from the mains and from the converter, in the case of powering a drill - it starts with some sound, but it works quite well Fine.

The board was painted by hand using an ordinary manicure

In the end, I liked the inverter so much that I decided to place it in a case from a computer power supply.
The REM function is also implemented; to turn on the circuit, you just need to connect the REM wire to the positive bus, then power will be supplied to the generator and the circuit will start working.

It’s quite possible to extract more power from such a circuit (500-600 Watts, maybe more), in the future I’ll try to increase the power, so the next article is just around the corner, see you next time...

List of radioelements

Designation	Type	Denomination	Quantity	Note	My notepad
VT1, VT2	Bipolar transistor	TIP41	2	KT819, KT805, KT815, KT817	To notepad
VT3...VT6	MOSFET transistor	IRFZ44	4	Replacement: IRFZ40/46/48, IRF3205/IRL3705	To notepad
C1, C2	Capacitor	2.2 µF	2		To notepad
R1...R4	Resistor	6.2 Ohm	4		To notepad
R5, R8	Resistor	680 Ohm	2		To notepad
R6, R7	Resistor

— when using low-power household appliances, especially in field conditions, there is a need to recharge their batteries. Therefore, in such cases, when there is no 220v power supply nearby, an inverter from 12 to 220 volts is very helpful.

I present to your attention a simple circuit of a DC voltage converter from 12v to 220v AC output. Initially, I was faced with the task of making an inexpensive, compact, low-power voltage conversion device. Therefore, it was decided to assemble it from the parts that I had on hand. The main components for assembling the inverter were components from an unnecessary computer power supply. But it is advisable to install a more powerful transformer. A low-power trans is not very suitable for such purposes; during operation it does not draw power more than 18-20 W. Radiators for cooling output transistors must be installed with a heat dissipation area based on more than 60 W of load.

Voltage converter circuit

The printed circuit board of the device must be placed in a housing that guarantees complete protection from the user touching high-voltage circuits.

Converter PCB

If you decide to use the inverter only to connect a TV or incandescent lamp to it, then you can do without a rectifier. By the way, the device works great with a compact fluorescent lamp, I tested it on a CFL with a power of 15 W - it starts up without problems. All components used were installed new, the only exception being the power transformer. Of course, in the future I have plans to make a couple more designs, taking into account the discovered features in the circuit and regarding the components.

The basic principle of operation of the circuit

DIY voltage converter 12-220 volts— a brief description of the circuit and the principle of its operation. This device, in principle, is nothing more than a push-pull pulse converter implemented on a TL494 pulse-width modulator. It is possible to use analogues of this PWM controller. Using this circuitry, the device turns out to be quite simple. High efficiency rectifier diodes are installed in the output circuit to double the voltage. However, the circuit can be used without the use of diodes, while obtaining an alternating voltage. For an electronic type ballast, direct current, as well as the polarity of the connection, does not matter. This is due to the fact that the electronic ballast circuit in the input circuit has its own diode bridge, assembled on fast-acting diodes.

Transformer

The converter circuit presented here uses an industrial high-frequency step-down transformer. Such trances are used in computer power supplies, only in this design it will act as the opposite of a booster. The step-down transformer can be removed from the AT power supply or from the ATX. A step-down or step-up transformer may differ from each other only in dimensions, everything else is the same. In principle, a transformer cannot be a step-up or step-down transformer; it all depends on its connection diagram.

Capacitor C1 – has a nominal value of 1 nF, (coding on the case is 102);
Resistor R1 – provides a range of pulses in the output circuit.
Resistor R2 - together with electrolyte C1 provides the operating frequency.

If it is necessary to increase the frequency, you need to reduce the resistance R1; if you need to reduce the frequency, then we increase the capacitance of the electrolytic capacitor C1.

Field effect transistors

The voltage inverter uses powerful field-effect transistors, which are distinguished by their speed and do not require complex control circuits. The following keys have proven themselves to work well: IRFZ44N, IRFZ46N, IRFZ48N. Practice has shown that during long-term operation of the device the keys do not get very hot, so a radiator for cooling the transistors is not required for this circuit. If it is necessary to place transistors on a heat sink, they must be secured through insulating gaskets. And the screws for fastening them must be used in conjunction with the insulating washer-bushing, which are available in the computer power supply.

But still, for testing the device, a cooling radiator would be useful. Consequently, in the event of a short circuit at the output or an error in the circuit, the output switches will not immediately fail due to overheating. The overload protection circuit can be implemented using a chain - a fuse, plus a diode at the input.

For myself, I made a converter using the well-known IRF540N field-effect transistors.

I decided to dedicate a separate article to the manufacture of a DC AC step-up voltage converter for 220V. This, of course, is remotely related to the topic of LED spotlights and lamps, but such a mobile power source is widely used at home and in the car.

1. Assembly options
2. Voltage converter design
3. Sine wave
4. Example of converter filling
5. Assembly from UPS
6. Assembly from ready-made blocks
7. Radio constructors
8. Power converter circuits

Assembly options

There are 3 optimal ways to make a 12 to 220 inverter with your own hands:

assembly from ready-made blocks or radio constructors;
manufacturing from an uninterruptible power supply;
use of amateur radio circuits.

From the Chinese you can find good radio constructors and ready-made blocks for assembling DC to AC 220V converters. In terms of price, this method will be the most expensive, but it requires the least amount of time.

The second method is to upgrade an uninterruptible power supply (UPS), which without a battery is sold in large quantities on Avito and costs from 100 to 300 rubles.

The most difficult option is assembly from scratch; you can’t do it without amateur radio experience. We will have to make printed circuit boards, select components, a lot of work.

Voltage converter design

Let's consider the design of a conventional step-up voltage converter from 12 to 220. The operating principle for all modern inverters will be the same. The high-frequency PWM controller sets the operating mode, frequency and amplitude. The power part is made of powerful transistors, the heat from which is transferred to the device body.

A fuse is installed at the input to protect the car battery from short circuits. A thermal sensor is attached next to the transistors, which monitors their heating. If the 12v-220v inverter overheats, an active cooling system consisting of one or more fans is turned on. In budget models, the fan can work constantly, and not just under high load.

Power transistors at the output

Sine wave

The signal shape at the output of a car inverter is generated by a high-frequency generator. A sine wave can be of two types:

modified sine wave;
pure sine wave, pure sine wave.

Not every electrical device can work with a modified sine wave, which has a rectangular shape. Some components change their operating mode, they can heat up and start to get dirty. You can get something similar if you dim an LED lamp whose brightness is not adjustable. The crackling and flashing starts.

Expensive DC AC step-up voltage converters 12V-220V have a pure sine wave output. They cost much more, but electrical appliances work great with it.

Example of converter filling

Assembly from UPS

In order not to invent anything and not to buy ready-made modules, you can try a computer uninterruptible power supply, abbreviated as UPS. They are designed for 300-600W. I have an Ippon with 6 sockets, 2 monitors, 1 system unit, 1 TV, 3 surveillance cameras, a video surveillance management system are connected. I periodically switch it to operating mode by disconnecting the 220 from the network so that the battery is discharged, otherwise the service life will be greatly reduced.

Electrician colleagues connected a regular car acid battery to an uninterruptible power supply, it worked perfectly for 6 hours continuously, and they watched football in the country. The UPS usually has a built-in gel battery diagnostic system that detects its low capacity. How it will react to the automobile is unknown, although the main difference is gel instead of acid.

UPS filling

The only problem is that the UPS may not like surges in the car network when the engine is running. For a real radio amateur, this problem is solved. Can only be used with the engine turned off.

Mostly UPSs are designed for short-term operation when 220V in the outlet disappears. For long-term continuous operation, it is highly advisable to install active cooling. Ventilation is useful for a stationary option and for a car inverter.

Like all devices, it will behave unpredictably when starting the engine with a connected load. The car's starter draws a lot of volts, at best it will go into protection as if the battery fails. At worst, there will be surges in the 220V output, the sine wave will be distorted.

Assembly from ready-made blocks

To assemble a stationary or automotive 12v 220v inverter with your own hands, you can use ready-made blocks that are sold on eBay or from the Chinese. This will save time on board manufacturing, soldering and final setup. It is enough to add a housing and wires with crocodiles to them.

You can also purchase a radio kit, which is equipped with all radio components; all that remains is to solder it.

Approximate price for autumn 2016:

300W – 400rub;
500W – 700rub;
1000W – 1500rub;
2000W – 1700rub;
3000W - 2500 rub.

To search on Aliexpress, enter the query in the search bar “inverter 220 diy”. The abbreviation "DIY" stands for "do-it-yourself assembly."

500W board, output 160, 220, 380 volts

Radio constructors

A radio kit costs less than a ready-made board. The most complex elements may already be on the board. Once assembled, it requires virtually no setup, which requires an oscilloscope. The range of radio component parameters and ratings are well chosen. Sometimes they put spare parts in a bag, in case you tear off the leg due to inexperience.

Power converter circuits

A powerful inverter is mainly used to connect construction power tools during the construction of a summer house or hacienda. A low-power 500-watt voltage converter differs from a powerful 5,000-10,000-watt converter in the number of transformers and power transistors at the output. Therefore, the manufacturing complexity and price are almost the same; transistors are inexpensive. The power is optimally 3000 W, you can connect a drill, grinder and other tools.

I will show several inverter circuits from 12, 24, 36 to 220V. It is not recommended to install these in a passenger car; you can accidentally damage the electrics. The circuit design of DC AC converters 12 to 220 is simple, a master oscillator and a power section. The generator is made on the popular TL494 or analogues.

A large number of booster circuits from 12v to 220v for DIY production can be found at the link
http://cxema.my1.ru/publ/istochniki_pitanija/preobrazovateli_naprjazhenija/101-4
In total there are about 140 circuits, half of them are boost converters from 12, 24 to 220V. Powers from 50 to 5000 watts.

After assembly, you will need to adjust the entire circuit using an oscilloscope; it is advisable to have experience working with high-voltage circuits.

To assemble a powerful 2500 Watt inverter you will need 16 transistors and 4 suitable transformers. The cost of the product will be considerable, comparable to the cost of a similar radio designer. The advantage of such costs will be a pure sine output.

Everyone is accustomed to electrical appliances operating on 220V. But what if you go on a hike or some long trip, and want to take convenient household appliances with you? They will not be able to work directly from the car battery; they simply do not have enough power. This is where voltage converters from 12 to 220V can come to the rescue.

What is a converter and its essence

Thanks to technological progress, these devices have become an order of magnitude smaller and more convenient. They are easy to carry and do not take up much space. The converters are capable of raising the battery voltage to 220V. They even work from the cigarette lighter. With the help of such inverters, you can easily install lighting in a tent, as well as power your tablet, laptop, and phone from them.

PWM controllers have made such devices more advanced. The efficiency increased noticeably, and the current shape became similar to a pure sine wave. But this is only in expensive devices. It became possible to increase power to several kW.

The duration of operation depends on the power and capacity of the batteries. Therefore, when going on a trip, it is better to limit yourself to electrical appliances with low energy consumption.

Today it is possible to buy various types of current converters that can produce power from several hundred watts to several kW. But for tourist trips it is worth purchasing a low-power inverter.

The only obstacle to their full application is the altered current shape. From an ordinary sinusoid, it turns into an almost rectangular shape. Not all household appliances are capable of working on it.

There are 3 types of converter design:

Automotive;
Compact;
Stationary.

It is worth noting that by increasing the load, the efficiency of the converter decreases. Stationary inverters can produce a sine wave. They are convenient to use to increase voltage from wind generators and solar panels.

Converter characteristics

Before purchasing, you need to know how to choose a voltage converter. The first thing you should pay attention to is its characteristics. Often sellers give incorrect inverter performance. Indicate its peak power, at which the device can operate for several minutes, after which it turns off due to overheating. This is how the most affordable converters are advertised.

Powerful DC-AC converters increase the voltage from 12V to 220V, the current shape and frequency are equal to the usual indicators of a home network. Therefore, all devices and tools are capable of working from it.

All current converters have the following parameters:

Operating power;
Cooling type;
Energy consumption during idle operation;
Maximum input current consumption;
Protective mechanisms against short circuit and overheating;
Output current shape;
Voltage level for power supply.

The high efficiency of modern inverters is due to the pulse controllers used in the design. Almost 95% of the energy goes to the payload. The rest dissipates in the device and heats it.

In the simplest and most accessible converters, the current sinusoid changes. It becomes rectangular, and in expensive and powerful devices the current shape remains the same smooth sinusoid as in a standard outlet.

Sometimes, the power of voltage converters may not be enough to run construction tools. For example, if a drill consumes 750W, then it will not run on a 1000W inverter. To solve this problem, soft starters are sold.

Stationary type converters are used for home work. These are powerful devices capable of delivering several thousand watts. More serious converters are used in enterprises; their power amounts to tens of thousands of watts.

For cars, low-power inverters of several hundred watts are used. Because the battery is not capable of operating for a long time under heavy loads.

It is not recommended to use the converter at maximum loads. Its service life will quickly decrease. Expensive devices have a power reserve, and in the most affordable ones this figure is slightly less than what is indicated on the case.

You need to buy a device that is 20% more powerful than the expected consumption. You also need to be interested in the type of power indicated on the case. She may be:

nominal;
long-lasting;
short-term.

Cooling type

Aluminum is a metal with high thermal conductivity, and converters (especially powerful ones) can overheat when operating under heavy loads. Therefore, the cases are made from this metal.

For an active cooling system, a fan is mounted in the case. It turns on when the temperature sensor detects an increase in temperature. In car inverters, fans can become clogged with dust, which leads to poor air ventilation and overheating.

The case may have passive cooling elements. They look like aluminum fins that help dissipate heat.

Homemade converter

Radio amateurs have the opportunity to make a simple inverter using the circuit. The result is a compact device capable of powering various pocket gadgets.

There are only four transistors in the circuit. Anyone who knows how to use a soldering iron can assemble it. The resulting device is convenient to use in a car. It is capable of providing a full-fledged 220V on-board socket.