DIY inverter repair 12 220

In detail: do-it-yourself repair of the 12 220 inverter from a real master for the site my.housecope.com.

The device is built on a push-pull inverter with two powerful field-effect transistors. Any N-channel field-effect transistors with a current of 40 Amperes or more are suitable for this design, I used inexpensive IRFZ44 / 46/48 transistors, but if you need more power at the output, it is better to use more powerful IRF3205 field-effect transistors.

We wind the transformer on a ferrite ring or an E50 armored core, and it is possible on any other. The primary winding should be wound with a two-core wire with a cross section of 0.8 mm - 15 turns. If we use an armored core with two sections on the frame, the primary winding is wound in one of the sections, and the secondary one consists of 110-120 turns of 0.3-0.4 mm copper wire. At the output of the transformer, we get an alternating voltage in the range of 190-260 Volts, rectangular pulses.

The voltage converter 12 220, the circuit of which was described, can supply various loads, whose power is not more than 100 watts

Output Pulse Shape - Rectangular

A transformer in a circuit with two 7 Volt primary windings (each arm) and a 220 Volt mains winding. Almost any transformers from uninterruptible power supplies are suitable, but with a power of 300 watts or more. Primary wire diameter 2.5 mm.

In their absence, IRFZ44 transistors can be easily replaced with IRFZ40,46,48 and even more powerful ones - IRF3205, IRL3705. Transistors in the TIP41 (KT819) multivibrator circuit can be replaced with domestic KT805, KT815, KT817, etc.

Attention, the circuit has no protection at the output and input from short circuit or overload, the keys will overheat or burn out.

Video (click to play).

Two options for the design of the printed circuit board and a photo of the finished converter can be downloaded from the link above.

This converter is powerful enough and can be used to power a soldering iron, grinder, microwave and other devices. But do not forget that its operating frequency is not 50 Hertz.

The primary winding of the transformer is wound with 7 cores at once, with a wire with a diameter of 0.6 mm and contains 10 turns with a tap from the middle stretched along the entire ferrite ring. After winding, we insulate the winding and start winding the step-up one, with the same wire, but already 80 turns.

It is advisable to install power transistors on heat sinks. If you assemble the converter circuit correctly, then it should work immediately and does not require adjustment.

As with the previous design, the heart of the circuit is the TL494.

This is a ready-made device for a push-pull pulse converter, its full domestic analogue is 1114EU4. At the output of the circuit, high-efficiency rectifier diodes and a C-filter are used.

In the converter, I used a ferrite W-shaped core from a TPI TV transformer. All native windings were unwound, because I rewound the secondary winding 84 turns with 0.6 wire in enamel insulation, then a layer of insulation and go to the primary winding: 4 oblique turns of 8 0.6 leads, after winding the windings were rang and divided in half, it turned out 2 windings of 4 turns in 4 wires, the beginning of one was connected to the end of the other, that is, I made a branch from the middle, and at the end I wound the feedback winding with five turns of PEL 0.3 wire.

The voltage converter 12 220 circuit that we have considered includes a choke. It can be made by hand by winding it on a ferrite ring from a computer power supply with a diameter of 10 mm and 20 turns with PEL 2 wire.

There is also a drawing of the printed circuit board of the voltage converter circuit 12 220 volts:

And a few photos of the resulting 12-220 Volt converter:

Again the TL494 I liked paired with mosfets (This is such a modern type of field-effect transistors), this time I borrowed the transformer from an old computer power supply. When laying out the board, I took into account the conclusions of it, so be careful with your placement option.

For the manufacture of the case, I used a 0.25L can of soda, so successfully sniffed after the flight from Vladivostok, with a sharp knife we cut off the top ring and cut out the middle of it, into it I glued a circle of fiberglass with holes for a switch and a connector on it on epoxy.

To make the jar stiff, I cut out a strip from a plastic bottle the width of our body, and coated it with epoxy glue, placed it in the jar, after the glue dried, the jar became quite rigid and with insulated walls, the bottom of the jar was left clean for better thermal contact with the radiator of the transistors.

At the end of the assembly, I soldered the wires to the lid, I fixed it with hot glue, this will allow, if it becomes necessary to disassemble the voltage converter, just heating the lid with a hairdryer.

The design of the converter is designed to convert 12 volt voltage from a battery into 220 volts alternating with a frequency of 50 Hz. The idea for the circuit is borrowed from an old November 1989 issue of radio magazine.

The radio amateur design contains a master oscillator designed for a frequency of 100 Hz on a K561TM2 trigger, a frequency divider by 2 on the same microcircuit, but on the second trigger, and a transistorized power amplifier loaded with a transformer.

Transistors, taking into account the output power of the voltage converter, should be installed on radiators with a large cooling area.

The transformer can be rewound from the old TS-180 mains transformer. The mains winding can be used as a secondary winding and then windings Ia and Ib are wound.

The voltage converter assembled from the working components does not require adjustment, with the exception of the selection of the capacitor C7 with the connected load.

If you need a printed circuit board drawing made in the sprint layout program, click on the PCB drawing.

Signals from the PIC16F628A microcontroller through 470 Ohm resistances control the power transistors, forcing them to open in turn. Semi-windings of a transformer with a power of 500-1000 VA are connected to the source circuits of the field transistors. There should be 10 volts on its secondary windings. If you take a Wire with a cross section of 3 mm.kv, then the output power will be about 500 watts.

The whole design is very compact, so you can use a breadboard without etching the tracks. Archive with the firmware of the microcontroller, follow the green link just above

The converter circuit 12-220 is made on a generator that creates symmetrical pulses, following in antiphase and the output unit is implemented on field switches, into which a step-up transformer is connected to the load. On elements DD1.1 and DD1.2, a multivibrator is assembled according to the classical scheme, generating pulses with a repetition rate of 100 Hz.

To form symmetrical pulses going in antiphase, the circuit uses a D-flip-flop of the CD4013 microcircuit. It divides by two all impulses entering its input. If we have a signal going to the input with a frequency of 100Hz, then the trigger output will be only 50Hz.

Since field-effect transistors have an insulated gate, the active resistance between their channel and the gate tends to an infinitely large value. To protect the trigger outputs from overload, the circuit has two buffer elements DD1.3 and DD1.4, through which the pulses follow to the field-effect transistors.

A step-up transformer is included in the drain circuits of the transistors. To protect against self-induction of self-induction on the drains, zener diodes of increased power are connected to them. HF interference suppression is carried out by a filter on R4, C3.

The winding of the choke L1 is made by hand on a ferrite ring with a diameter of 28mm. It is wound with a PEL-2 wire 0.6 mm in one layer.The transformer is the most common network for 220 volts, but with a power of at least 100W and having two secondary windings of 9V each.

To increase the efficiency of the voltage converter and prevent severe overheating, field-effect transistors with low resistance are used in the output stage of the inverter circuit.

On DD1.1 - DD1.3, C1, R1, a rectangular pulse generator with a pulse repetition rate of 200 Hz is made. Then the pulses are fed to a frequency divider built on the elements DD2.1 - DD2.2. Therefore, at the output of the divider 6 output DD2.1, the frequency is reduced to 100Hz, and already at the 8th output DD2.2. it is 50 Hz.

The signal from the 8th output of DD1 and from the 6th output of DD2 follows to the diodes VD1 and VD2. To fully open the field-effect transistors, it is required to increase the amplitude of the signal that passes from the diodes VD1 and VD2; for this, bipolar transistors VT1 and VT2 are used in the voltage converter circuit. By means of VT3 and VT4 field-effect transistors are controlled. If no mistakes were made during the assembly of the inverter, then it starts working immediately after the power is turned on. The only thing that is recommended to do is to select the value of the resistance R1 so that the usual 50 Hz is at the output.

A transformer for a 12 220 voltage converter circuit can be made by hand. To do this, you will have to slightly redo the old power transformer from a domestic TV. We remove all windings, except for the network. Then we wind two windings with a PEL wire - 2.1 mm. Field-effect transistors are required to be installed on the radiator.

In this converter circuit, the generator generates rectangular pulses with a repetition rate of about 50 Hz with protective pauses, which exclude the simultaneous opening of field-effect transistors VT5 and VT6. When a low level appears at the output of Q1 (or Q2), the transistors VT1 and VT3 (or VT2 and VT4) will open, and the gate capacitors begin to discharge, and the transistors VT5 and VT6 are closed.
The converter itself is assembled according to the classic push-pull circuit.
If the voltage at the output of the converter exceeds the set value, the voltage across the resistor R12 will be higher than 2.5 V, and therefore the current through the DA3 stabilizer will increase sharply and a high level signal will appear at the FV input of the DA1 microcircuit.

Its outputs Q1 and Q2 will switch to the zero state and the field-effect transistors VT5 and VT6 will close, causing a decrease in the output voltage.
A current protection unit is also added to the voltage converter circuit, based on the K1 relay. If the current flowing through the winding is higher than the set value, the contacts of the reed switch K1.1 will work. At the FC input of the DA1 chip, there will be a high level and its outputs will go into a low level state, causing the VT5 and VT6 transistors to close and a sharp decrease in current consumption.

After that, DA1 will remain in a locked state. To start the converter, a voltage drop at the IN DA1 input is required, which can be achieved either by turning off the power supply or by short-circuiting C1. To do this, you can introduce a momentary button into the circuit, the contacts of which are soldered parallel to the capacitor.
Since the output voltage is a square wave, capacitor C8 is intended for smoothing it. The HL1 LED is required to indicate the presence of the output voltage.
The T1 transformer is made of TC-180 and can be found in the power supplies of old CRT TVs. All its secondary windings are removed, and the mains supply for a voltage of 220 V is left. It serves as the output winding of the converter. Semi-windings 1.1 and I.2 are made of PEV-2 wire 1.8, 35 turns each. The beginning of one winding is connected to the end of the other.
The relay is homemade. Its winding consists of 1-2 turns of insulated wire, designed for a current of up to 20. 30 A. The wire is wound on a reed switch housing with NO contacts.

By selecting the resistor R3, you can set the required frequency of the output voltage, and the resistor R12 - the amplitude from 215.220 V.

there are 2 inverters 12v-220v

visually all right no damage

I read that the only thing that can break there is MOSPHETS, I dropped them all and checked them with a multimeter as in the video

the first, the smaller one, when connected to 12v, loaded the source so that the source did not smoke 220v, the cooling fan does not rotate

on top he has 4 mosfets ftp10n40 2 of them are corpses judging by the check

below NCE55h12 - one of them is a corpse

after desoldering all mosfets, the fault continues to burn

the second inverter, when turned on, the fault indicator is on, the cooling fan rotates, there is 5V at the USB output. 220v is missing. after desoldering all mosfets, the fault does not burn

below it has 4 mosfets IRF3205, judging by the check, all are alive

top left to right: IRF740B is dead, IRF740A is dead, and 2 IRF740s are alive.

I tried to solder the surviving mosfets to both the first and second inverters - but neither the first nor the second worked.

what is the problem: mosfets are not interchangeable, the verification method from the video above is not perfect, or there may be other non-working parts?

As an option, evaporate and poke them (transyukas) into a voltmeter to check transistors?

In inverters, a lot of things can fail, electrolytes, diodes, anything you like, and you need to carefully consider the circuit and poke a multimeter on the voltage map.

Mosfets cannot be checked like that. they do not have a base, emitter and collector to plug into a multimeter

schemes could not be found since this is not a corporate thing, but China at its best.

the diodes checked everything - in one direction they ring in the opposite direction.

electrolytes "suspicious" on the advice from the first comment evaporated and checked with a tester as far as possible - there is not a single short circuit when dialing the resistance grows indefinitely - which indicates that they are charging

Read also: Meat grinder DIY repair

Cool mastech and the like have testers for mosfeet

The fact that the electrolyte is not in short circuit does not mean that it is in good working order, its capacity may be 1 μF, which means that it will work differently.

If you have never repaired a power supply unit that exploded into the trash, then you will not fix them either. IMHO of course, but 99.9% sure. Good luck.

Check mosfets with a tseshka, kz in any direction indicates that the fetus is dead.

check tl-ki. need an oscilloscope. if not, change it to knowingly live ones.

so-so advice, with the same success you can advise to throw

In the top photo at the top left, it looks like a bloated electrolyte - you need to look carefully.

Buy or squeeze arduin nano, build tTester M328 from it. Checks mofsets, containers, and much more. On the arduino_ru forum, you can find a circuit and firmware in the form of .ino, with them you don't even need a display - all data can be obtained via USB. A nano, even in a chipdip, costs a couple of hundred square meters, additional parts are needed for a penny.

A car voltage inverter is sometimes incredibly useful, but most of the products in stores either sin in quality, or do not suit in terms of power, and are not cheap at the same time. But after all, the inverter circuit consists of the simplest parts, therefore we offer instructions for assembling a voltage converter with our own hands.

The first thing to consider is the loss of electricity conversion, released in the form of heat on the keys of the circuit. On average, this value is 2–5% of the nominal power of the device, but this indicator tends to grow due to improper selection or aging of components.

The removal of heat from semiconductor elements is of key importance: transistors are very sensitive to overheating and this is expressed in the rapid degradation of the latter and, probably, their complete failure. For this reason, the base for the case should be a heat sink - an aluminum radiator.

Of the radiator profiles, the usual "comb" 80–120 mm wide and about 300–400 mm long is well suited. shields of field-effect transistors are fastened to the flat part of the profile with screws - metal spots on their back surface. But even with this, not everything is simple: there should be no electrical contact between the screens of all the transistors of the circuit, therefore the radiator and fasteners are insulated with mica films and cardboard washers, while a thermal interface is applied on both sides of the dielectric gasket with a metal-containing paste.

It is extremely important to understand why an inverter is not just a voltage transformer, and also why there is such a diverse list of such devices.First of all, remember that by connecting the transformer to a direct current source, you will not receive anything at the output: the current in the battery does not change polarity, respectively, the phenomenon of electromagnetic induction in the transformer is absent as such.

The first part of the inverter circuit is an input multivibrator that simulates the oscillations of the network for making a transformation. It is usually assembled on two bipolar transistors that can swing power switches (for example, IRFZ44, IRF1010NPBF or more powerful - IRF1404ZPBF), for which the most important parameter is the maximum permissible current. It can reach several hundred amperes, but in general, you just need to multiply the value of the current by the voltage of the battery to get an approximate number of watts of output power without taking into account losses.

Simple converter based on multivibrator and power field switches IRFZ44

The frequency of the multivibrator is not constant, calculating and stabilizing it is a waste of time. Instead, the current at the output of the transformer is converted back to constant current by means of a diode bridge. Such an inverter can be suitable for powering purely active loads - incandescent lamps or electric heaters, stoves.

On the basis of the resulting base, you can collect other circuits that differ in the frequency and purity of the output signal. The selection of components for the high-voltage part of the circuit is easier to make: the currents here are not so high, in some cases the assembly of the output multivibrator and filter can be replaced with a pair of microcircuits with the appropriate strapping. Capacitors for the load network should be electrolytic, and for circuits with a low signal level - mica.

A variant of the converter with a frequency generator on K561TM2 microcircuits in the primary circuit

It is also worth noting that in order to increase the final power, it is not at all necessary to purchase more powerful and heat-resistant components of the primary multivibrator. The problem can be solved by increasing the number of converter circuits connected in parallel, but each of them will require its own transformer.

Option with parallel connection of circuits

Voltage inverters are now used everywhere by both motorists who want to use household appliances away from home, and by residents of autonomous homes powered by solar energy. And in general, we can say that the width of the spectrum of current collectors that can be connected to it directly depends on the complexity of the converter device.

Unfortunately, a pure "sine" is present only in the main power grid, it is very, very difficult to achieve the conversion of direct current into it. But in most cases this is not required. To connect electric motors (from drills to coffee grinders), a pulsating current with a frequency of 50 to 100 hertz is sufficient without smoothing.

ESL, LED lamps and all kinds of current generators (power supplies, chargers) are more critical to the choice of frequency, since it is at 50 Hz that their scheme of operation is based. In such cases, microcircuits, called a pulse generator, should be included in the secondary vibrator. They can switch a small load directly, or act as a "conductor" for a series of power switches of the inverter output circuit.

But even such a cunning plan will not work if you plan to use the inverter to provide stable power supply to networks with a mass of dissimilar consumers, including asynchronous electrical machines. Here, pure "sine" is very important and only digitally controlled frequency converters can do this.

For the assembly of the inverter, we are missing only one circuit element that performs the transformation of low voltage to high voltage. You can use transformers from power supplies of personal computers and old UPSs, their windings are just designed for the transformation of 12 / 24-250 V and vice versa, it remains only to correctly determine the conclusions.

And yet it is better to wind the transformer with your own hands, since the ferrite rings make it possible to do it yourself and with any parameters.Ferrite has excellent electromagnetic conductivity, which means that transformation losses will be minimal even if the wire is hand wound and not tight. In addition, you can easily calculate the required number of turns and the thickness of the wire using calculators available on the network.

Before winding the core ring, you need to prepare - remove the sharp edges with a file and wrap tightly with an insulator - fiberglass impregnated with epoxy glue. This is followed by the winding of the primary winding from a thick copper wire of the calculated cross-section. After dialing the required number of turns, they must be evenly distributed over the surface of the ring at equal intervals. The winding leads are connected according to the diagram and insulated with heat shrinkage.

The primary winding is covered with two layers of polyester tape, then the high-voltage secondary winding and another layer of insulation are wound. An important point - you need to wind the "secondary" in the opposite direction, otherwise the transformer will not work. Finally, a semiconductor thermal fuse must be soldered to one of the taps, the current and operating temperature of which are determined by the parameters of the secondary winding wire (the fuse case must be tightly tied to the transformer). The top of the transformer is wrapped with two layers of vinyl insulation without an adhesive backing, the end is fixed with a tie or cyanoacrylate glue.

It remains to assemble the device. Since there are not so many components in the circuit, they can be placed not on the printed circuit board, but by surface mounting with attachment to the radiator, that is, to the device body. We solder to the pin legs with a mono-core copper wire of a sufficiently large cross-section, then the junction is strengthened with 5-7 turns of thin transformer wire and a small amount of POS-61 solder. After the connection has cooled down, it is insulated with a thin heat shrink tube.

High power circuits with complex secondary circuits may require a printed circuit board with transistors in a row at the edge for free attachment to the heatsink. For the manufacture of a seal, glass fiber laminate with a foil thickness of at least 50 microns is suitable, but if the coating is thinner, reinforce the low voltage circuits with copper wire jumpers.

Making a printed circuit board at home is easy today - the Sprint-Layout program allows you to draw clipping stencils for circuits of any complexity, including for double-sided boards. The resulting image is printed by a laser printer on high-quality photo paper. Then the stencil is applied to the cleaned and defatted copper, ironed, the paper is washed off with water. The technology received the name "laser-ironing" (LUT) and is described in the network in sufficient detail.

You can etch the remains of copper with ferric chloride, electrolyte or even table salt, there are plenty of ways. After etching, the stuck toner must be washed off, the mounting holes must be drilled with a 1 mm drill and walked along all the tracks with a soldering iron (submerged arc) in order to tin the copper of the contact pads and improve the conductivity of the channels.

200A, see the 7th graph in the datasheet.

But this is closer to the truth. We look at the wahs of the field workers' diodes - at some current, the voltage dropped on them, which on the wahs of the "protective" element lies in the area of exceeding the parameters - this is a trifle and burns out, a considerable part of the converter current takes over, and the converter itself worked correctly. But, from overheating of the burnt (sih) parts it could hurt him too.

Let's wait for the author, maybe there is something new.

So I am about it. ...

Last edited by Borodach on Thu Nov 10, 2011 12:29:40 PM, edited 1 time in total.

followed by an explanation about diodes
I understand that it will fall on them even less (LH did not look)
so, how something small will burn, I still do not understand
And I did not see the transformer, the magnetic circuit, as well as the converter itself
that's why I asked for a photo
yes, and I do not insist on anything, I just assume

and there have been different cases in my practice, so I'm not surprised at anything for a long time

there was a case with a client recently
they say that the converter has discharged the battery (2 accumulators of 190 Ah in series) to 1 Volt
At night it squeaked and turned off, in the morning they could not turn it on
removed it from the battery and measured it with a tester - 1V.
brought for repair
I say, this cannot be
Yesterday I went to the object, on batteries 24.6 Volts
I say, did you charge them? NO, not charged.
They say they recovered themselves, read on the Internet, the "memory effect" is called
Well, I understood, it's useless to argue, the wife and husband (the engineer from his words) unanimously repeat - there was 1B, you saw it yourself
I arrived at work, puzzled all the way how this could be.
I told my colleagues, laughed, dispersed, there are no versions
Half an hour later, a friend comes up, I know where 1B comes from.
takes the tester and on my working battery, I look - on display 1. and it is definitely normal (battery)
it turns out that if the tester is used at the wrong limit, less than rev. voltage, it shows 1 or -1, depending on the polarity of the connection
And I forgot about it, my tester has automatic limits.
these "engineers" sometimes fool around

_________________
Don't teach me how to live, better help me financially.

To connect household appliances to the on-board electrical system of a car, an inverter is required, which can increase the voltage from 12 V to 220 V. There are sufficient quantities of them on store shelves, but their price is not encouraging. For those who are a little familiar with electrical engineering, it is possible to assemble a 12 220 volt voltage converter with your own hands. We will analyze two simple schemes.

There are three types of converters 12-220 V. The first is that 220 V is obtained from 12 V. Such inverters are popular among motorists: through them you can connect standard devices - TVs, vacuum cleaners, etc. The reverse conversion - from 220 V to 12 - is rarely required, usually in rooms with severe operating conditions (high humidity) to ensure electrical safety. For example, in steam rooms, swimming pools or bathrooms. In order not to risk it, the standard voltage of 220 V is lowered to 12 using appropriate equipment.

There are enough voltage converters in stores

The third option is, rather, a stabilizer based on two converters. First, standard 220V is converted to 12V, then back to 220V. This double conversion allows you to have a perfect sine wave at the output. Such devices are essential for the normal operation of most electronic household appliances. In any case, when installing a gas boiler, it is strongly advised to power it through such a converter - its electronics are very sensitive to the quality of the power supply, and replacing the control board costs about half the boiler.

The circuit is simple, the parts are readily available, most of them can be removed from the computer power supply or purchased from any electronics store. The advantage of the circuit is simplicity of implementation, the disadvantage is an imperfect sinusoid at the output and a frequency higher than the standard 50 Hz. That is, devices that require power supply cannot be connected to this converter. You can directly connect not very sensitive devices to the output - incandescent lamps, iron, soldering iron, phone charger, etc.