Schematic diagram of the inverter 12 v 220. High voltage and not only

Inverter 12V / 220V is a necessary thing on the farm. Sometimes it’s just necessary: ​​the network, for example, is gone, and the phone is discharged and there is meat in the refrigerator. Demand determines supply: for ready-made models of 1 kW or more, from which you can power any electrical appliances, you will have to pay somewhere from $ 150. Possibly over $300. However, making a do-it-yourself voltage converter in our time is accessible to anyone who knows how to solder: assembling it from a ready-made set of components will cost three to four times cheaper + a little work and metal from improvised trash. If there is for car batteries (batteries), you can generally meet 300-500 rubles. And if you also have basic amateur radio skills, then, having rummaged through the stash, it is quite possible to make a 12V DC / 220V AC 50Hz inverter for 500-1200 W for nothing. Consider the possible options.

Options: global

A 12-220 V voltage converter to power a load of up to 1000 W or more can generally be made independently in the following ways (in order of increasing costs):

1. Place a finished block in a case with a heat sink from Avito, Ebay or AliExpress. Searched for "inverter 220" or "inverter 12/220"; you can immediately add the required power. Will cost approx. half the price of the same factory. Electrical skills are not required, but - see below;
2. Assemble the same from the set: printed circuit board + “scatter” component. It is purchased there, but diy is added to the request, which means for self-assembly. Price still approx. 1.5 times lower. You need basic skills in radio electronics: use a multimeter, knowledge of the wiring (pinouts) of the outputs of active elements or the ability to search for them, the rules for including polar components (diodes, electrolytic capacitors) in the circuit and the ability to determine what current of which section wires are needed;
3. Adapt a computer uninterruptible power supply (UPS, UPS) for the inverter. A serviceable used UPS without a standard battery can be found for 300-500 rubles. No skills are needed - the auto battery is simply connected to the UPS. But you will have to charge it separately, also see below;
4. Choose a conversion method, a diagram (see below) according to your needs and the availability of parts, calculate and assemble completely on your own. Perhaps for nothing, but in addition to basic electronic skills, you will need the ability to use some special measuring instruments (also see below) and perform simple engineering calculations.

From the finished module

Assembly methods according to paragraphs. 1 and 2 are actually not that simple. Cases of ready-made factory inverters serve at the same time as heat sinks for powerful transistor switches inside. If we take a "semi-finished product" or "placer", then there will be no case for them: at the current cost of electronics, manual labor and non-ferrous metals, the difference in prices is explained precisely by the absence of the second and, possibly, the third. That is, you will have to make a radiator for powerful keys yourself or look for a ready-made aluminum one. Its thickness at the place where the keys are installed should be from 4 mm, and the area for each key should be from 50 square meters. see per kW of output power; with airflow from a computer fan-cooler for 12 V 110-130 mA - from 30 sq. cm*kw*key.

For example, in a set (module) there are 2 keys (they can be seen, they stick out of the board, see on the left in the figure); modules with keys on the radiator (on the right in the figure) are more expensive and are designed for a certain, as a rule, not very high power. There is no cooler, the power needed is 1.5 kW. So, you need a radiator from 150 sq. see In addition to it, installation kits for keys: insulating heat-conducting gaskets and accessories for mounting screws - insulating cups and washers. If the module has thermal protection (some other wick will stick out between the keys - a thermal sensor), then a little thermal paste to stick it to the radiator. Wires - of course, see below.

From UPS (UPS)

An inverter 12V DC/220 V AC 50 Hz, to which you can connect any devices within the allowable power, is made from a computer UPS quite simply: regular wires to “your” battery are replaced with long ones with clips for the car battery terminals. The cross section of the wires is calculated based on the allowable current density of 20-25 A / sq. mm, see also below. But because of a non-standard battery, problems may arise - with it, but it is more expensive and more necessary than a converter.

The UPS also uses lead-acid batteries. Today, this is the only widely available secondary chemical power supply capable of regularly delivering high currents (extra currents) without being completely “killed” in 10-15 charge-discharge cycles. In aviation, silver-zinc batteries are used, which are even more powerful, but they are terribly expensive, they are not widely used, and their resource is negligible by household standards - approx. 150 cycles.

The discharge of acid batteries is clearly monitored by the voltage on the bank, and the UPS controller will not allow the "foreign" battery to be discharged beyond measure. But in regular UPS batteries, the electrolyte is gel, and in car batteries it is liquid. The charge regimes in both cases are significantly different: such currents cannot be passed through the gel as through a liquid, and in a liquid electrolyte with a too low charge current, the ion mobility will be low and not all of them will return to their places in the electrodes. As a result, the UPS will chronically undercharge the auto battery, it will soon become sulphated and become completely unusable. Therefore, a battery charger is needed in the kit for the inverter on the UPS. You can make it yourself, but that's another topic.

Battery and power

The suitability of the converter for a particular purpose also depends on the battery. The step-up voltage inverter does not take energy for consumers from the "dark matter" of the Universe, black holes, the holy spirit, or from somewhere else just like that. Only - from the battery. And from it he will take the power given to consumers, divided by the efficiency of the converter itself.

If you see a branded inverter “6800W” or more on the case, believe your eyes. Modern electronics makes it possible to place even more powerful devices in the volume of a cigarette pack. But, let's say we need a load power of 1000 W, and we have a regular 12 V 60 A / h car battery at our disposal. The typical inverter efficiency is 0.8. So, from the battery, he will take approx. 100 A. For such a current, wires with a cross section of 5 square meters are also needed. mm (see above), but this is not the main thing here.

Motorists know: the starter drove for 20 minutes - buy a new battery. True, in new machines there are time limits for its operation, so perhaps they don’t know. And not everyone knows for sure that the starter of a passenger car, having untwisted, takes a current of approx. 75 A (within 0.1-0.2 s at startup - up to 600 A). The simplest calculation - and it turns out that if there is no automation in the inverter that limits the discharge of the battery, then ours will sit down completely in 15 minutes. So choose or design your converter taking into account the capabilities of the available battery.

Note: this implies a huge advantage of 12/220 V converters based on computer UPSs - their controller will not allow the battery to completely drain.

The resource of acid batteries does not noticeably decrease if they are discharged with a 2-hour current (12 A for 60 A / h, 24 A for 120 A / h and 42 A for 210 A / h). Taking into account the conversion efficiency, this gives the permissible continuous load power in approx. 120W, 230W and 400W resp. For 10 min. load (for example, for powering a power tool), it can be increased by a factor of 2.5, but after that the ABA must rest for at least 20 minutes.

In general, the result is not entirely bad. From a conventional household power tool, only a grinder can take 1000-1300 watts. The rest, as a rule, cost up to 400 W, and screwdrivers up to 250 W. The refrigerator from the battery 12 V 60 A / h through the inverter will work for 1.5-5 hours; enough to take the necessary action. Therefore, it makes sense to make a 1 kW converter for a 60 A / h battery.

What will be the output?

In order to reduce the weight and size of the device, voltage converters, with rare exceptions (see below), operate at elevated frequencies from hundreds of Hz to units and tens of kHz. No consumer will accept a current of this frequency, and the loss of its energy in ordinary wiring will be huge. Therefore, inverters 12-200 are built for the output voltage next. types:

• Constant rectified 220 V (220V AC). Suitable for powering phone chargers, most power supplies (IP) tablets, incandescent lamps, fluorescent housekeepers and LED. For power from 150-250 W, they are perfect for hand-held power tools: the power consumed by them at direct current is slightly reduced, and the torque increases. Not suitable for switching power supplies (UPS) of TVs, computers, laptops, microwave ovens, etc. with a power of more than 40-50 W: in such there must be a so-called. starting node, for normal operation of which the mains voltage must periodically pass through zero. Unsuitable and dangerous for devices with power transformers on iron and AC motors: stationary power tools, refrigerators, air conditioners, most Hi-Fi audio, food processors, some vacuum cleaners, coffee makers, coffee grinders and microwaves (for the latter - due to the presence of a table rotation motor).
• Modified sine wave (see below) - suitable for all consumers, except for Hi-Fi audio with a UPS, other devices with a UPS from 40-50 W (see above) and often local security systems, home weather stations, etc. with sensitive analog sensors.
• Pure sinusoidal - suitable without restrictions, except for power, for any consumer of electricity.

Sine or pseudosine?

In order to increase efficiency, voltage conversion is carried out not only at higher frequencies, but also with multipolar pulses. However, it is impossible to power many consumer devices with a sequence of bipolar rectangular pulses (the so-called meander): large surges at the meander fronts with at least a little reactive load will lead to large energy losses and can cause a consumer malfunction. However, it is also impossible to design a converter for a sinusoidal current - the efficiency will not exceed approx. 0.6.

A quiet but significant revolution in this industry occurred when microcircuits were developed specifically for voltage inverters, forming the so-called. modified sinusoid (on the left in the figure), although it would be more correct to call it pseudo-, meta-, quasi-, etc. sinusoid. The current form of the modified sinusoid is stepped, and the pulse fronts are tightened (meander fronts are often not visible on the screen of a cathode-ray oscilloscope). Thanks to this, consumers with iron-based transformers or noticeable reactivity (asynchronous electric motors) “understand” the pseudosine wave “as real” and work as if nothing had happened; Hi-Fi audio with a network transformer on iron can be powered by a modified sine wave. In addition, the modified sinusoid can be smoothed out in fairly simple ways to “almost real”, the differences from the pure one on the oscilloscope are barely noticeable; "Pure sine" type converters are not much more expensive than conventional ones, on the right in fig.

However, it is undesirable to start devices with capricious analog nodes and UPS from a modified sinusoid. The latter is highly undesirable. The fact is that the average area of ​​the modified sinusoid is not a pure zero voltage. The UPS startup node from the modified sine wave does not work clearly and the entire UPS may not exit the startup mode to the working one. The user sees this at first as ugly glitches, and then smoke comes out of the device, as in a joke. Therefore, the devices in the UPS must be powered by Pure Sine inverters.

We make the inverter ourselves

So, while it is clear that it is best to make an inverter for an output of 220 V 50 Hz, although we will also remember about the AC output. In the first case, you will need a frequency meter to control the frequency: the norms for fluctuations in the frequency of the power supply network are 48-53 Hz. AC electric motors are especially sensitive to its deviations: when the frequency of the supply voltage reaches the tolerance limits, they heat up and "leave" from the nominal speed. The latter is very dangerous for refrigerators and air conditioners; they can permanently fail due to depressurization. But there is no need to buy, rent or beg for a time an accurate and multifunctional electronic frequency meter - we do not need its accuracy. Either an electromechanical resonant frequency meter (pos. 1 in the figure), or a pointer of any system, pos. 2:

Both are inexpensive, sold on the Internet, and in big cities in electrical special stores. An old resonant frequency meter can be found on the iron market, and one or the other, after setting up the inverter, is very suitable for controlling the mains frequency in the house - the meter does not respond to connecting them to the network.

50 Hz from computer

In most cases, 220 V 50 Hz power is required for not very powerful consumers, up to 250-350 watts. Then the basis of the 12/220 V 50 Hz converter can be a UPS from an old computer - unless, of course, this one is lying around in the trash or someone is selling it cheaply. The power delivered to the load will be approx. 0.7 of the nominal UPS. For example, if “250W” appears on its case, then devices up to 150-170 W can be connected fearlessly. Need more - you must first check on the load of incandescent lamps. Withstood 2 hours - it is able to give such power for a long time. How to make a 12V DC/220V AC 50Hz inverter from a computer power supply, see the video below.

Video: a simple 12-220 converter from a computer PSU

Keys

Let's say there is no computer UPS or more power is needed. Then the choice of key elements becomes important: they must switch high currents with the lowest switching losses, be reliable and affordable. In this regard, bipolar transistors and thyristors in this field of application are surely becoming a thing of the past.

The second revolution in the inverter business is associated with the emergence of powerful field-effect transistors (“field workers”), the so-called. vertical structure. However, they turned the whole technique of power supply of low-power devices upside down: it is becoming increasingly difficult to find a transformer on iron in the “home appliances”.

The best of the high power field converters for voltage converters - insulated gate and induced channel (MOSFET), e.g. IFR3205, on the left in the figure:

Due to the negligible switching power, the efficiency of an inverter with a DC output on such transistors can reach 0.95, and with an AC output of 50 Hz 0.85-0.87. MOSFET analogues with built-in channel, e.g. IFRZ44, give lower efficiency, but are much cheaper. A pair of one or the other allows you to bring the power to the load up to approx. 600W; both can be paralleled without problems (on the right in the figure), which makes it possible to build inverters for power up to 3 kW.

Note: the switching loss power of switches with a built-in channel when operating on a significantly reactive load (for example, an asynchronous electric motor) can reach 1.5 W per switch. Keys with an induced channel are free from this shortcoming.

TL494

The third element that made it possible to bring voltage converters to their current state is the specialized TL494 microcircuit and its analogues. All of them are a pulse-width modulation (PWM) controller that generates a modified sine wave signal at the outputs. The outputs are bipolar, which allows you to control pairs of keys. The reference conversion frequency is set by one RC circuit, the parameters of which can be changed over a wide range.

When the permanence is enough

The range of 220 V DC current consumers is limited, but they just need an autonomous power supply not only in emergency situations. For example, when working with a power tool on the road or in the far corner of your own site. Or it is always present, say, at the emergency lighting of the entrance to the house, hallway, corridor, house territory from a solar battery that recharges the battery during the day. The third typical case is charging the phone on the go from the cigarette lighter. Here, the output power is needed very little, so that the inverter can be made with only 1 transistor according to the relaxation oscillator circuit, see next. video clip.

Video: single transistor boost converter

Already to power 2-3 LED bulbs, more power is needed. The efficiency of blocking generators when trying to "squeeze" it drops sharply, and you have to switch to circuits with separate timing elements or full internal inductive feedback, they are the most economical and contain the least number of components. In the first case, for switching one key, the self-induction EMF of one of the transformer windings is used together with a timing circuit. In the second, the step-up transformer itself is the frequency-setting element due to its own time constant; its value is determined mainly by the phenomenon of self-induction. Therefore, those and other inverters are sometimes called self-induction converters. Their efficiency, as a rule, is not higher than 0.6-0.65, but, firstly, the circuit is simple and does not require adjustment. Second, the output voltage is trapezoidal rather than square wave; "Demanding" consumers "understand" it as a modified sine wave. The disadvantage is that field keys in such converters are practically inapplicable, because often fail from voltage surges on the primary winding during switching.

An example of a circuit with external timing elements is given in pos. 1 fig.:

The author of the design failed to squeeze more than 11 watts out of it, but apparently he confused ferrite with carbonyl iron. In any case, the armored (cup) magnetic circuit in his own photo (see the figure on the right) is by no means ferrite. It looks more like an old carbonyl one, oxidized on the outside from time to time, see fig. on right. It is better to wind the transformer for this inverter on a ferrite ring with a ferrite cross-sectional area of ​​​​0.7-1.2 square meters. see. The primary winding should then contain 7 turns of wire with a copper diameter of 0.6-0.8 mm, and the secondary 57-58 turns of wire 0.3-0.32 mm. This is under straightening with doubling, see below. Under the "clean" 220 V - 230-235 turns of wire 0.2-0.25. In this case, this inverter, when replacing KT814 with KT818, will give power up to 25-30 W, which is enough for 3-4 LED lamps. When replacing KT814 with KT626, the load power will be approx. 15 W, but the efficiency will increase. In both cases, the key radiator is from 50 sq. cm.

At pos. 2 shows a diagram of an "antediluvian" converter 12-220 with separate feedback windings. It's not that archaic. First, the output voltage under load is a trapezoid with rounded fractures without spikes. It's even better than the modified sine wave. Secondly, this converter can be made without any alterations in the circuit for power up to 300-350 W and a frequency of 50 Hz, then a rectifier is not needed, you just need to put VT1 and VT2 on radiators from 250 sq. see each. Thirdly, it saves the battery: when overloaded, the conversion frequency drops, the output power decreases, and if you load it even more, the generation fails. That is, no automation is required to avoid overdischarging the battery.

The calculation procedure for this inverter is given in the scan in Fig.:

The key quantities in it are the conversion frequency and the working induction in the magnetic circuit. The conversion frequency is selected based on the material of the available core and the required power:

Type Magnetic core	Induction / conversion frequency
	Up to 50 W	50-100W	100-200W	200-350W
"Power" iron from power transformers with a thickness of 0.35-0.6 mm	0.5T/(50-1000)Hz	0.55T/(50-400)Hz	0.6T/(50-150)Hz	0.7T/(50-60)Hz
"Sound" iron from output transformers UMZCH with a thickness of 0.2-0.25 mm	0.4 T/(1000-3000)Hz	0.35T/(1000-2000)Hz	-	-
"Signal" iron from signal transformers with a thickness of 0.06-0.15 mm (not permalloy!)	0.3T/(2000-8000)Hz	0.25T/(2000-5000)Hz	-	-
Ferrite	0.15 T/(5-30) kHz	0.15 T/(5-30) kHz	0.15 T/(5-30) kHz	0.15 T/(5-30) kHz

Such an "omnivorous" ferrite is explained by the fact that its hysteresis loop is rectangular and the working induction is equal to the saturation induction. The decrease in comparison with typical calculated values ​​of induction in steel magnetic cores is caused by a sharp increase in switching losses of non-sinusoidal currents as it increases. Therefore, no more than 100-120 watts can be removed from the core of the power transformer of an old 270-watt “coffin” TV in this 50 Hz converter. But - on lack of fish and cancer fish.

Note: if there is a steel magnetic circuit with a deliberately oversized cross section, do not squeeze power out of it! Let it be better that the induction be less - the efficiency of the converter will increase, and the shape of the output voltage will improve.

straightening

It is better to rectify the output voltage of these inverters according to the scheme with parallel voltage doubling (pos. 3 in the figure with diagrams): the components for it will be cheaper, and the power losses on the non-sinusoidal current will be less than in the bridge. Capacitors must be taken "power", designed for high reactive power (with the designations PE or W). If you put "sound" without these letters, they can just explode.

50 Hz? It's very simple!

A simple 50 Hz inverter (pos. 4 of the figure above with diagrams) is an interesting design. Some types of typical power transformers have their own time constant close to 10 ms, i.e. half period 50 Hz. By correcting it with time-setting resistors, which will simultaneously limit the control current of the keys, you can immediately get a smoothed 50 Hz meander at the output without complex formation schemes. Transformers TP, CCI, TN for 50-120 W are suitable, but not all. You may need to change the resistor values ​​and / or connect 1-22 nF capacitors in parallel with them. If the conversion frequency is still far from 50 Hz, it is useless to disassemble and rewind the transformer: the magnetic core glued with ferromagnetic glue will fluff up, and the transformer parameters will deteriorate sharply.

This inverter is a country weekend converter. He will not land the car battery for the same reasons as the previous one. But it will be enough to light the house with a veranda with LED lamps and a TV or a vibration pump in the well. The conversion frequency of a well-established inverter when the load current changes from 0 to the maximum does not go beyond the technical standard for power supply networks.

The windings of the original transformer are bred as follows. In typical power transformers, there is an even number of secondary windings for 12 or 6 V. Two of them are “delayed”, and the rest are soldered in parallel into groups of an equal number of windings in each. Next, the groups are connected in series so that 2 half-windings of 12 V each are obtained, this will be a low-voltage (primary) winding with a midpoint. Of the remaining low-voltage windings, one is connected in series with a 220 V network, this will be a step-up winding. An additive to it is needed, because. the voltage drop on the keys of bipolar composite transistors, together with its losses in the transformer, can reach 2.5-3 V, and the output voltage will be underestimated. Additional winding will bring it to normal.

DC from chip

The efficiency of the described converters does not exceed 0.8, and the frequency, depending on the load current, noticeably floats. The maximum load power is less than 400 W, so it's time to think about modern circuit solutions.

A diagram of a simple converter 12 V DC / 220 V DC for 500-600 W is shown in the figure:

Its main purpose is to power hand-held power tools. Such a load is not demanding on the quality of the input voltage, so the keys are taken cheaper; IFRZ46, 48 are also suitable. The transformer is wound on a ferrite with a cross section of 2-2.5 square meters. cm; a power transformer core from a computer UPS is suitable. Primary winding - 2x5 turns of a bundle of 5-6 winding wires with a copper diameter of 0.7-0.8 mm (see below); secondary - 80 turns of the same wire. Establishment is not required, but there is no control over the discharge of the battery, so during operation you need to attach a multimeter to its terminals and do not forget to look at it (the same applies to all other home-made voltage inverters). If the voltage drops to 10.8 V (1.8 V per can) - stop, turn off! It dropped to 1.75 V per cell (10.5 V for the entire battery) - this is already sulfation!

How to wind a transformer on a ring

The quality characteristics of the inverter, in particular, its efficiency, are quite strongly affected by the stray field of its transformer. The fundamental solution for its reduction has long been known: the primary winding, which “pumps” the magnetic circuit with energy, is placed close to it; secondary above it in descending order of their power. But technology is such a thing that sometimes theoretical principles in specific designs have to be turned inside out. One of Murphy's laws says approx. so: if the piece of iron, well, it still doesn’t want to work as it should, try to do the opposite in it. This fully applies to a high-frequency transformer based on a ferrite annular magnetic core with windings made of relatively thick rigid wire. The voltage converter transformer is wound on a ferrite ring as follows:

• The magnetic circuit is isolated and, using a winding shuttle, a secondary step-up winding is wound on it, laying the turns as tightly as possible, pos. 1 in the figure:

• Tightly fit the "secondary" with adhesive tape, pos 2.
• Prepare 2 identical wire harnesses for the primary winding: wind the number of turns of half of the low-voltage winding with a thin unusable wire, remove it, measure the length, cut off the required number of winding wire segments with a margin and assemble them into bundles.
• Additionally, the secondary winding is isolated until a relatively flat surface is obtained.
• They wind the “primary” with 2 bundles at once, arranging the wires of the bundles with a tape and evenly distributing the turns over the core, pos. 3.
• The ends of the bundles are called and the beginning of one is connected to the end of the other, this will be the middle point of the winding.

Note: on electrical circuit diagrams, the beginning of the windings, if it matters, are indicated by a dot.

50 Hz smooth

A modified sine wave from a PWM controller is not the only way to get 50 Hz at the inverter output, suitable for connecting any household electricity consumers, and even that would not hurt to “smooth” it. The simplest of them is the good old iron transformer, it “strokes” well due to its electrical inertia. True, finding a magnetic circuit for more than 500 W is becoming increasingly difficult. Such an isolation transformer is switched on to the low-voltage output of the inverter, and a load is connected to its step-up winding. By the way, most computer UPSs are built according to this scheme, so they are quite suitable for this purpose. If you wind the transformer yourself, then it is calculated similarly to the power one, but with a trace. features:

• The initially determined value of the working induction is divided by 1.1 and is used in all further calculations. So it is necessary to take into account the so-called. form factor of non-sinusoidal voltage Kf; for a sinusoid, Kf \u003d 1.
• The step-up winding is first calculated as a 220 V mains winding for a given power (or determined by the parameters of the magnetic circuit and the value of the working induction). Then the found number of its turns is multiplied by 1.08 for powers up to 150 W, by 1.05 for powers of 150-400 W and by 1.02 for powers of 400-1300 W.
• Half of the low-voltage winding is calculated as secondary for a voltage of 14.5 V for bipolar switches or with a built-in channel and for 13.2 V for switches with an induced channel.

Examples of circuit solutions for converters 12-200 V 50 Hz with an isolating transformer are shown in the figure:

On the one on the left, the keys are controlled by the master oscillator on the so-called. "soft" multivibrator, it already generates a meander in littered fronts and smoothed breaks, so no additional smoothing measures are required. The frequency instability of a soft multivibrator is higher than usual, so a potentiometer P is needed to adjust it. With the keys on the KT827, you can remove power up to 200 W (radiators - from 200 sq. cm without airflow). Keys on KP904 from old trash or IRFZ44 allow you to increase it to 350 W; single on IRF3205 up to 600 W, and paired on them up to 1000 W.

An inverter 12-220 V 50 Hz with a master oscillator on the TL494 (on the right in the figure) keeps the frequency iron in all imaginable unimaginable operating conditions. For more efficient smoothing of the pseudosinusoid, the so-called phenomenon is used. indifferent resonance, in which the phase ratios of currents and voltages in the oscillatory circuit become the same as in acute resonance, but their amplitudes do not noticeably increase. Technically, this is solved simply: a smoothing capacitor is connected to the step-up winding, the capacitance value of which is selected according to the best form of current (not voltage!) Under load. To control the current shape, a 0.1-0.5 Ohm resistor is included in the load circuit for a power of 0.03-0.1 of the nominal, to which an oscilloscope with a closed input is connected. The smoothing capacitance does not reduce the efficiency of the inverter, but you cannot use the oscilloscope's low-frequency simulation computer programs for tuning, because. the input of the sound card that they use is not designed for an amplitude of 220x1.4 = 310 V! The keys and powers are the same as before. case.

A more advanced converter circuit 12-200 V 50 Hz is shown in Fig.:

It uses complex composite keys. To improve the quality of the output voltage, it uses the fact that the emitter of planar epitaxial bipolar transistors is doped much more strongly than the base and collector. When TL494 applies a closing potential, for example, to the VT3 base, its collector current will stop, but due to the absorption of the emitter space charge, it will slow down the blocking of T1 and the voltage surges from the self-induction EMF Tr will be absorbed by the circuits L1 and R11C5; they will “tilt” the fronts more. The output power of the inverter is determined by the overall power Tr, but not more than 600 W, because it is impossible to use paired powerful switches in this circuit - the spread in the gate charge of MOSFET transistors is quite significant and the switching of the keys will be fuzzy, which may even worsen the shape of the output voltage.

Inductor L1 is 5-6 turns of wire with a diameter of 2.4 mm or more over copper, wound on a piece of a ferrite rod with a diameter of 8-10 m and a length of 30-40 mm in increments of 3.5-4 mm. The magnetic circuit of the throttle must not be closed! Establishing a circuit is a rather painstaking task and requires considerable experience: you need to select L1, R11 and C5 according to the best shape of the output current under load, as in the previous one. case. On the other hand, Hi-Fi, powered by this converter, remains "Hi-Fi" to the most demanding ears.

Is it possible without a transformer?

Already a winding wire for a powerful 50 Hz transformer will cost a pretty penny. More or less magnetic circuits are available from “coffin” transformers up to 270 W overall, but in an inverter you cannot squeeze out more than 120-150 W from this, and the efficiency will be 0.7 at best, because. "Coffin" magnetic circuits are wound from a thick tape, in which eddy current losses are large at non-sinusoidal voltage on the windings. It is generally problematic to find an SL magnetic circuit from a thin tape capable of delivering more than 350 W at an induction of 0.7 T, it will cost a lot, and the entire converter will turn out to be huge and unbearable. UPS transformers are not designed for frequent continuous operation - they heat up and their magnetic circuits in inverters degrade pretty soon - the magnetic properties deteriorate greatly, the converter power drops. Is there a way out?

Yes, and such a solution is often used in proprietary converters. This is an electric bridge from keys on high-voltage power field-effect transistors with a breakdown voltage of 400 V and a drain current of more than 5 A. Suitable from the primary circuits of computer UPSs, and from old trash - KP904, etc.

The bridge is powered by a constant 220 V DC from a simple 12-220 inverter with rectification. The arms of the bridge open in pairs crosswise alternately, and the current in the load included in the diagonal of the bridge changes direction; control circuits of all keys are galvanically isolated. In industrial constructions, the keys are controlled from special ICs with optocoupler decoupling, but in amateur conditions, both can be replaced with an additional low-power inverter 12 V DC - 12 V 50 Hz, running on a small iron transformer, see fig. The magnetic circuit for it can be taken from a Chinese market low-power power transformer. Due to its electrical inertia, the quality of the output voltage is even better than the modified sine wave.

Comments (40):

#1 Snow White February 19 2015

Perfetto. Excellent This circuit seems to be what I was looking for about the transistor in a very interesting way. If we increase the number of turns, say three times, the current at KT 817 will also decrease to 0.6. He does not have enough speed is this the reason for the high current?

To be honest, I didn’t try to increase the turns. But what speed is not enough, yes, that’s why it was replaced by kt940. current can be further reduced. take only the lamp itself from the lamp and throw the board out of it. then the current lies within 0.3-0.35A ..

#3 Selyuk May 12 2015

Everything is very "simple", but where can I get transformer cups ??

#4 root May 12 2015

There is no gap between the ferrite cups in the design of the transformer of this high-voltage converter, so you can try using a ferrite ring or a frame from a pulse transformer with a ferrite core (you can take it from a non-working power supply from a computer).
You will need to experiment with the number of turns and the output voltage.

#5 pavel June 01 2015

And what is the principle of calculating the transformer and selecting transistors for this inverter? I would like to make one with a power supply of 60 volts.

The cups were taken because they simply were, and the number of turns in such a core is needed less. I have not tried ferrite rings, it works fine on a regular W-shaped ferrite. I don’t remember how many turns I wound, it’s like a primary - 12 turns with a 0.5 mm wire, and increasing just by eye, until the frame on the core is filled. The transformer was taken from a 4 by 5 cm monitor.

#7 Egor October 05 2015

I have a question for you, how much is the resistor on the left ohm at 220 ???
I'm just not very good at electronics.

#8 root October 05 2015

If there are only numbers near the resistor, then the resistance is in ohms. In the diagram, the resistor has a resistance of 220 ohms.

Tell me, is it possible to use your circuit to power the MTX-90 thyratron and not from 12, but from a 3.7 volt battery?
If possible, which transistors are better to take? The MTX-90 has a small operating current - from 2 to 7 mA, and the voltage for ignition needs about 170 volts, well, you can experiment with a transformer (about voltage).

I don't even know what to answer. Somehow I didn’t think about it .. And why do you need to feed the thyratron from this circuit? In principle, it will work, of course, the only question is how .. from 3.7 volts is also possible, but it is necessary to recalculate the windings or select them empirically.

#11 Oleg December 13 2015

People, tell me how to make an inverter from transistors from a Chinese typewriter on the control panel. Is it possible to put a ring ferrite core and is it possible to make a difference in turns by 3 times? I do this inverter for interest and to make it easier. And is it possible to put the voltage at the input somewhere around 3v?
Answer please! I will be glad if you answer all my questions! I'm waiting for your answers!

#12 Alexander December 17 2015

I have 30\10 ferrite cups, is it possible to wind a trance on them and how many turns should be wound, well, at least approximately.

#13 Alexander January 24 2016

Everything works great there, both a 15 watt lamp and a 20 watt lamp. You just need more powerful transistors. KT940 can not be touched, but 814 could be replaced at least with KT837. And if the current is high, you don’t need to rewind anything, you just need to increase the value of the resistor 3.1k. And the transformer is not necessarily of such dimensions, even a pulse from charging will work, transistors will still play a special role. p.s. These transistors have a power of no more than 10 watts.

#14 Eduard February 01 2016

What kind of transistor can replace kt814? Can it be 13005 or kt805?

#15 Alexander February 03 2016

Change it to kt805 - you’ll scrape off a lot of power, because kt805 can give up to 60 watts according to the datasheet

KT814 is p-n-p conductivity, and KT805 and 13005 are n-p-n ..., of course not Edward ...

#17 mar May 11 2016

instead of kt814 I put kt816,15W lamp pulled.

#18 sasha November 06 2016

put kt805 and kt837. primary 16v.0.5mm. secondary 230v. 0.3mm. lamp 23w. glow great.

#19 Edward November 19 2016

March. counter question, then how can you replace kt940, so that kt814 is replaced with kt805 or 13005 and change the polarity of the power supply? I think it should work, but if you replace the bunch of kt814 and kt940 with something more modern, can you squeeze out up to 40 watts of power? I also want to try to do it on the uc3845 PWM controller, the circuit is generally primitive: the UC3845 microcircuit, in its circuit the frequency-setting resistor and film capacitor, the IRFZ44 field-effect transistor and the transformer from the electronic transformer included in the circuit as a boost, as a result we have up to 100 W power at 12 volts

and why ".. 940 outputs in the old colors in a shaft .. everyone has nowhere to go ... replace with any reverse transistor, but you want 805, then yes .. 940 on direct conduction .... and change the polarity ... but again, why all such trans. everyone has unmeasured in the bins ...

#21 pavel February 09 2017

why do you need to increase the power of the circuit :)? what, will you use KrAZ batteries (190 a / h) ?? this circuit makes sense, as the comrade correctly said, if you use a bulb from a lamp with a burnt circuit. otherwise, to hell with the button accordion: an LED lamp from the same battery, with the same light output, will enlighten many times longer! ..

#22 Pavel February 09 2017

now about transistors: you can change them, but you need to remember that any power transistor provides its declared power only when using an appropriate heat sink. this fact directly affects the dimensions of the entire device. and where do you get energy. l amp more powerful than 30 watts = 150? I haven't seen it for sale. and I already spoke about the battery for such a "pacifier" :). so, know the measure, inventors, good luck!

#23 Eduard February 24 2017

March, here I just have a problem with the Soviet kt940 and kt814. Basically in my stocks are imported powerful high-frequency bipolar transistors 13005 for 5 amperes 400 volts, and the like. skies kt814 and kt805 BY THEMSELVES GLUGY BOIL FAST EVEN WITH A RADIATOR

I would not argue that kt805 are buggy .. depending on which ones to use. unreliable in plastic, there is such a thing, and then for some 80 years. take 805 in metal, so just an indestructible transistor. however, it is necessary to emphasize the fact that they are buggy not because they are bad, but because they fell into not quite skillful hands, just

and you can put at least imported microwave transistors, it will work !!! verified!!. I did not pursue in this article to create a miniature lamp, but how to fit a burned-out lamp at minimal cost. to still serve

collector 814 should be grounded through a 10 microfarad capacitor, otherwise the surge is very large when switching.
814 transistor is in a half-open state - it needs a radiator, however.

it was easier to use a blocking generator.

what other capacitor is 10 microfarads, what kind of nonsense, is it really invisible from the photo that a miniature radiator will fit everything into a pack of cigarettes. and the blocking generator is not easier to use. You need at least three windings. and the transistor will heat up there no less !!!

#28 IamJiva August 14 2017

the blocking generator serves the same purpose, to carry out feedback (bring a microphone to the speaker so that it buzzes), if you did without a microphone - what for, you don’t need it, you got by adding a transistor, you can get by with one transistor in blocking, and turn the phase with turns of the winding, which (allow) are independently connected in any polarity. it is possible to squeeze out a lot of watts but it is difficult, part of the energy (for powerful lamps is significant, up to 90%) is lost on the diode bridge and electrolyte (in the lamp rectifier) ​​cheap (especially if powerful) and 50 Hz suitable, at 50 kHz smoke can already go from them and the voltage will not appear to start the lamp, 50 Hz diodes (simple, that is, not ultrafast and not Schottky) do not have time to lock up, and drain the charge back to the winding or somewhere else, from this the heating of everything and the incorrect operation of the generator, the electrolyte has an inductance (series), and it only "recognizes" a short pulse, but is in no hurry to fulfill the order, waiting for the command to set aside ... the current starts to increase to infinity or how much they will give, for 50Hz instantly, for 50kHz - never ... the transistor needs to be fast, it can warm up and in NO way at the same time, IRF840 4 ohm speakers 500wt each, 2000Wt power in class D powered by + -85V (170V) TL494 PWM, Ir2112 driver in gates, 4pcs ultrafast diodes shunt SV and IC, varistors 400V BC 30V SV
2 kW drum and bass power, they were a little warm on the same radiators as here, at the output of the choke from the TVS and 200 turns, at 2500wt they burned out without warning
it would be nice to shunt with a diode, or better with a varistor, the output transformer of the primary would be nice here (from flyback pulses possible in the event of a load disconnection, the selection of transistors and turns of the primary for maximum efficiency is also important and valuable here as the ratio of sugar and vinegar with water + time on a timer in the microwave to get away, take it out and pull out lollipops, the circuit works like a juggler that you have never seen, hope for ease of transferring the ideal-harmony-efficiency-power in another circus and a jacket is not necessary

One question for the author. This converter will pull the electric shaver Kharkiv, Agidel, Berdsk, etc.
I need just such a miniature one that would always be built into a car for shaving.
Just do not write that the sale is full of electric shavers from batteries and clockwork. I am dear to me.
She's been with me for half my life.
Good luck.

#30 root January 21 2018

To power a 220V electric shaver from the on-board network of a car, it is better to assemble some kind of more reliable and powerful voltage converter. Here are some such schemes:

1. Voltage inverter 12V to 220V from available parts (555, K561IE8, MJ3001)
2. Simple voltage inverter 13V-220V for car (CD4093, IRF530)

Thanks for the links, but it's too expensive and difficult to assemble on the knee.
I don't have those details. But the old color.tel. and there is a tape recorder. It's all right there
People write that you can increase the power by replacing transistors with 805.837.
The electric shaver consumes 30 watts. It might pull. What do you think.

Fell into the hands of ROM Variom A.

The trouble is that the P216G transistors cannot be found now, namely one of them is not working. According to the parameters, the GT701A seems to be suitable, but here's how to determine the resistors. There are only 4 of them, two pairs. Just replacing both P216Gs with GT701A, I don’t think it will work. Tell.

#33 root February 05 2018

Agu1954, P216 transistors can be replaced with GT701A or P210V. Below are the main performance limits of these transistors:

• P216G: Ukb, max=50V; Ik max=7.5A; Pk max=24W; h21e>5; f gr.> 0.2 MHz;
• P210V: Ukb, max=45V; Ik max=12A; Pk max=45W; h21e>10; f gr.> 0.1 MHz;
• GT701A: Ukb, max=55V; Ik max=12A; Pk max=50W; h21e>10; f gr.=0.05 MHz;

Replace two P216 transistors with GT701A (P210V). For safety reasons, the first connection of the circuit to the battery should be made through a 3A fuse.

P.S. questions that are not related to the scheme that is given in the publication, please ask on the forum or in our social groups VK and FB.

#34 Sergey February 16 2018

#35 root February 16 2018

Hello Sergey. An old, and no longer working, postal address was indicated. Fixed it with a new one.

#36 Sergey February 16 2018

This converter operates at a frequency far greater than 50Hz. somewhere in the region of 20-50 kHz. even if you increase the power by replacing the transistors with more powerful ones, the razor will still not work. just physically the engine will not be able to operate at a frequency of tens of kilohertz

#38 Petro Kopitonenko November 19 2018

To reduce the frequency of the current on the converter, you must try to increase the number of turns of the transformer, both the primary winding and the secondary. What am I coming from. 50 hertz transformers have a large number of turns. And high-frequency - a small number of turns. This is the same as in oscillatory circuits, the frequency depends on the number of turns. I've soldered an experimental converter with a factory transformer at 50 hertz. There, two primary windings are wound with 40 turns instead of 10 turns according to the scheme. I heard the transformer buzzing at a frequency of about 40 hertz by ear. If it was a frequency of 50 kilohertz, I would not have heard anything!!!

#39 David June 13 2019

And you can use a ready-made transformer in this circuit. For example, a step-up transformer TP 30-2, just connect the other way around (to the output winding of 15 volts)

#40 root June 15 2019

The circuit needs a high-frequency transformer, TP 30-2 or another network one with W-like or toroidal iron will not work here.

Hello. Today I will talk about a fairly powerful converter (inverter) from 12 volts DC to 220 volts AC. The declared power of this converter is as much as 3000 watts. Like it or not, I'll try to show in the review.
Also in the review there will be a disassembly, a detailed examination of all the insides, testing.
The subject was bought for $55.38 + $19.57 shipping, only $74.95. Now it's a little more expensive.
Interested please...

Motivation:

Why do I need this inverter? The fact is that my car is in the yard of an apartment building without a garage and I can’t simply vacuum it. Tried to use a car 12 volt vacuum cleaner, but by and large it's a toy. So I decided to look in the direction of such converters. I have a 1500 watt vacuum cleaner, so I decided to take an inverter with 2 power reserves.

Packaging and equipment:

The parcel arrived by EMS, but this did not save her from the "professional" actions of the Russian Post employees. It seems that the parcel was not just thrown, but walked on it with their feet. But the metal case of the inverter was almost not damaged.


The complete set is the most ascetic: an inverter, 2 short cables, instructions in English and Chinese.

Inverter:

The overall dimensions of the inverter are: 28x15x7 cm;
Weight about 2 kg.
The inverter is made in an aluminum case, on one end of which there are power terminals for connecting 12 volts, as well as 2 fans. On the second end there is a socket for connecting the load, a power switch, 2 LEDs (green and red), a USB socket. The green LED lights up during the normal operation of the inverter, red when one of the protections is triggered. Also, together with the glow of the red LED, the inverter emits a rather loud and nasty squeak.
Protection is triggered in the following cases:
- supply voltage output from the range of 10-15V;
- inverter overheating;
- inverter overload.

Disassembly:

To disassemble the inverter housing, it is necessary to unscrew 8 screws from the ends (4 from each) and remove the upper part of the housing.
Blockwise, the internal filling of the device can be represented as follows:
Now I will describe in words. At the input of the inverter there are 4 converters from 12 volts DC to 300 volts DC. All these 4 converters are connected in parallel. Each converter consists of 2 CMP1405 FETs, a step-up transformer and a full-wave UF2004 diode rectifier. Transistors are quite powerful (maximum drain current is 140 amperes), but with diodes, everything is not so good. Diodes are only 2 amps. But since in a diode bridge they work alternately, then in theory the maximum output current of each of the 4 converters is 4 amperes. Those. 16 amps with 4 converters. Those. the total output power is as much as 4800 watts. Seems to be stock too.

The generator on the TL494 chip controls the operation of field-effect transistors of all converters

So, at the output of the 4 converters described above, 300 volts of direct current is obtained. To turn it into alternating current, another converter is used, from direct current to alternating current. It is also made on the TL494 chip, to the output of which a bridge amplifier of 4 R6025ANZ field effect transistors is connected

The maximum drain current of these transistors is 25 amperes, and if we consider that the transistors also work alternately, then here we have a very large power margin.
Well, the main parts of the "stuffing" are disassembled, but nothing is said about the USB connector. This connector can be used to charge various USB devices, however, 5 volts for it is generated by a conventional 7805 linear regulator, which does not even have a heatsink, so I would not recommend connecting anything more or less voracious to this socket.

Testing:

To begin, I will demonstrate the waveform at the output of the inverter
This is the so-called "modified sine wave". Most of these converters and various uninterruptible power supplies output alternating current with just this waveform. It is much easier and cheaper to obtain such an alternating current than a "pure sine wave", and most modern electrical appliances can be used as a load. The exception is various loads with an inductive component, for example, asynchronous electric motors, transformers, etc. Switching power supplies and collector motors work fine even from direct current, so they “digest” the “modified sine wave” well.
It's time to move on to testing itself. To do this, the inverter was connected directly to the car battery, though through 4-meter extension wires, because. regular wires are very short and without "crocodiles" at the ends. A vacuum cleaner with a power of 1500 W was used as a load.
When checking the work with the engine turned off, the vacuum cleaner worked intermittently, because. less than 10 volts reached the inverter input (the rest fell on the wires), and the inverter turned off for protection. With the engine running, the voltage at the input of the inverter was kept around 10.8 volts, at the output 207 volts, the vacuum cleaner worked perfectly.

Video review:

In the video review, unpacking, disassembly, testing of the monitored inverter.

Outcome:

The inverter is fully operational, and can be used for its intended purpose. I did not like the input wires, I will lengthen them and equip them with "crocodiles". I plan to buy +36 Add to favorites Liked the review +56 +81

There are completely different situations when the owner needs to create a new voltage converter at home. The main purpose of this device is to provide a value in the mains voltage with a value of 220 V from the initial values ​​​​of 12 watts. A do-it-yourself 12 to 220 inverter is made by most amateurs, since a good quality converter is quite expensive. Before assembling the device, you should understand the principle of its operation in order to have an idea about the mechanism of its operation.

In what areas is the voltage inverter 12 220 V used

With stable use of the battery, a gradual decrease in its charge level occurs. The converter stabilizes the voltage if there is no electricity.

A do-it-yourself 12 220 V inverter will allow you to improve engineering structures in any room. The value of the power of devices that convert current is selected according to the total values ​​of the loads being operated. Power consumption processes can be reactive and active. Reactive loads do not fully consume the received amount of energy, due to which the value of the apparent power is greater than its active value.

Pure sine wave inverters are used when connecting an element with a total power of 3 kW. Significant fuel savings are provided by the use of voltage converters and mini-power plants.

The following consumers are connected to the inverter design:

• alarm system;
• boiler;
• pumping apparatus;
• computer system.

The advantage of using voltage converters

Due to the fact that inverters have a number of positive characteristics, they are very much appreciated when used for various types of electrical engineering. The devices operate silently, do not pollute the environment with all sorts of exhausts. The cost of maintaining such devices is minimal: there is no need to check the pressure in the engine. Inverters have rather insignificant mechanical wear, which allows them to be used by various consumers. Inverters 12 220 V operate at increased power KR121 EU, have increased efficiency.

In the process of assembling inverters with driving devices as multivibrators, the advantage of converters is expressed in the fact that the device has accessibility and simplicity. The size of the products is compact, it is not difficult to repair them, and they can be operated even at low temperatures.

Scheme and principle of operation of the inverter 12 220

The main part of radio components using inverters use high frequencies in their work. The pulse inverter fully replaces the classical circuit in which transformers are used. The K561TM2 microcircuit is formed by two D-flip-flops, which have an R and S input. Such a microcircuit is created taking into account the use of CMOS technologies, by enclosing it in a plastic case.

Inverter master generators are mounted taking into account K561TM2, using the DD1 device for operation. Trigger DD1.2 is mounted on the frequency divider. Amplifying stages receive a signal from microcircuits.

For operation, the selection of KT827 transistors is performed. If they are absent, then a transistor of the KT819 GM type or a field semiconductor - IRFZ44 will do.

Sine wave generators for inverter 12-220V operate at high frequencies. To form a circuit with a size of 50 Hz, a secondary winding is used with capacitors and loads connected in parallel. By connecting any device, the inverters create a converting voltage of 220 V.

The circuit has one significant drawback - the imperfect shape of the parameters at the outputs.

Speaking about how the 12 220 inverter works, it is worth pointing out that the K561TM2 chip duplicates the K564TM2. You can increase the power on the converter by selecting a more intense transistor. It is important to consider the fact which capacitors are installed at the outputs. They have a voltage of 250 V.

Transducer with latest parts

A self-made inverter can operate in a stable mode if the outputs of the transistor operate from an amplified source with a main generator. For this, it is allowed to use elements of the KT819GM ​​series installed on overall radiators.

When creating converters, a simplified scheme is used. During the process, you should take care of acquiring the necessary materials:

• microcircuits KR121EU1;
• transistors IRL2505;
• soldering iron;
• tin.

Microcircuits KR12116U1 have a remarkable property: they contain a pair of channels for regulating the key and make it quite easy to make a simple voltage converter. Microcircuits in the temperature range from +25 to +30 ° C give the limiting voltage value within 3 and 9 V.

The frequency of master oscillators is determined by the parameter of the element in the circuits. The IRL2505 transistor is installed when used on the outputs. It should receive a signal with the proper level, due to which the output transistor is adjusted.

The formed low levels do not allow the transistor to move from closed modes to any other states. As a result, the occurrence of instantaneous current flows is fully eliminated when the keys are opened at the same time. If there is a hit of high levels to the first output, then this helps to turn off the pulsed generations. The circuit determines the connection of the common wire to pin 1.

To perform the installation of push-pull cascades, T1 transformers and transistors are used, in the amount of two pieces: VT1 and VT2. In open channels, you can see the resistance value from 0.008 ohms. It is insignificant, in connection with this, the power value of the transistor is small, even if a large current passes. Output transformers with a power of 100 W allow the IRL2505 current to be applied to 104 A, and pulse transformers are 360 ​​A.

The main features of inverters include the ability to use any transformer that has two 12 V windings at the outputs.

If the output power is about 200 W, then in such cases the transistor is not installed on the radiator. It is important to consider that the value of the electric current with a power of 400 W reaches about 40 A.

How does an inverter for fluorescent lamps

To make a converter that will allow you to illuminate a room of any size or a car, it is enough to use the do-it-yourself assembly scheme. VOLTSL pulse converters are push-pull. They are mounted on power supplies TL 494 (KS 1114EU4). Microcircuits are controlled by the power parts of the power supply and consist of:

• voltage generator;
• voltage stabilizing source;
• two transistors on the output sources of electric current, the capacity of which is 0.7 mm and 0.1 V.

To perform the installation, it is necessary to provide for the purchase of rectifier diodes and a transformer from the power supply. It is necessary to deal with the issue of rewinding transformers. Doing this work yourself, you should calculate up to 100 kHz. Each resistor is purchased, taking into account the circuit R1 and R2, which creates the passage of a current pulse at the output. The operating frequency is formed when creating the circuit C1 and R3. HR307 diodes are mounted, if they are absent, then HER304 is used. KD213 diodes have proven themselves quite well. The selection of capacitors is carried out with a different capacitance. Soldered microcircuits are placed in panels. The circuits can function for four hours - the design of the transistors does not overheat, and they do not need to be tuned.

Transformers are subject to self-winding. Therefore, it is necessary to stock up in advance with ferrite rings, the diameter of which is 30 mm. The warp uses a winding ratio of 1:120, while 1:1 is the primary and 20 is 200 turns with the secondary.

Initially, the secondary winding is wound using a wire with a cross section of 0.4 mm. At the next stage, a primary coating is created, which consists of 2 halves with ten turns on each of them. Stranded soft wire with a diameter of 0.8 mm is used to create a half-winding. To remake the transformer, it is allowed to use a device for a 12-volt lamp that illuminates the ceiling. The secondary winding is removed, and a half-winding is created when the coatings are wound, when the wire is folded in half. After that, the connecting place is cut, and each end of the wires is soldered together, due to which the center of the winding is formed.

For uninterrupted operation, it is necessary to use powerful metal conductors or field-effect transistors IRFL44N LRF46N. Diodes HER307 and KD213 are installed for converters. Computer power supplies are used as capacitors, with a diameter of 18 mm.

During prolonged work, the transistors heat up, the installation of radiators is not carried out. If it is supposed to be used, then the flanges on the transistor case should not be wrapped through resistors. The washer and padding insulating materials from the PC power supplies should be used.

Inverters are reliably protected against overload if a fuse and a diode are installed on the outputs. It is important that safety regulations are strictly observed: that is, high voltages must be avoided. Charges in capacitors can be stored for 24 hours. Discharging is carried out using 220 V incandescent lamps.

Do-it-yourself inverter 12 to 220 can be made according to a simple scheme. Such a device is considered a fairly convenient device that allows you to receive a voltage of 220 V. Any home-made devices in some situations are absolutely in no way inferior to factory products, and in some cases even surpass them.

Video "Creating a converter for fluorescent lamps"