High voltage and more. High voltage and more Converter from Soviet parts 12 220V
The initial goal for the project was to make a powerful 12 to 220 converter. The main advantage of this device is its ease of assembly, made using a push-pull circuit. Only 2 field-effect transistors, without any master oscillators. Even if you have experience in such a matter as assembling a converter, but there is a great desire to try, then there is nothing difficult about it, you can easily assemble it with your own hands.
It is not necessary to buy any parts for the device; all components can be found at home in old equipment.
Let's watch a video of the converter:
As for the converter parameters, unfortunately, the output frequency is variable, but you can easily turn it into direct current by installing a rectifier and a large capacitor at the output with a calculated capacitance of about 100 microfarats, at a voltage of 400 volts. The operating frequency depends on the LC circuit. We use the primary winding of the coil as a coil. 2 throttles installed. The winding has no tap.
Powerful high-voltage channel transistors are used as power switches. They can be replaced with any low-voltage ones. Power primarily depends on the transformer and fawn transistors.
As for the circuit, it will allow you to remove up to 500 watts or half a kilowatt of output power, without any master circuits or other structures.
On the generator board itself, in addition to the transistor, zener diodes are also installed to stabilize the gate voltage. There is also a 470 ohm shutter stop; for the design, anything from 100 to 670 ohms can be used.
In addition, 2 diodes are installed.
When using one common heat sink, they must be insulated with gaskets and insulating washers.
If the inductor overheats a little, you need to wrap it with a wire with a diameter of up to 2 mm.
The transformer used a ready-made 220 volt with a primary winding. The winding consists of 8 turns of thick wire.
The diagram can be without a midpoint or with a midpoint.
In our case, an 11-watt incandescent lamp is connected. We need to illuminate it with full heat.
All of the above devices can be powered from direct current. You cannot power a refrigerator, vacuum cleaner, or microwave. You can power the charger from your phone, laptop, or even your computer.
A homemade voltage converter (inverter) of 12 volts to 220 volts can be useful for motorists who drive their cars into nature, fishing, or dachas. It allows you to charge your phone, connect lamps for lighting at night, work and play on your laptop, and watch TV.A 12 volt to 220 volt converter with a maximum output power of 500 W is assembled on 2 domestic microcircuits (K155LA3 and K155TM2) and 6 transistors, and several radio components. To increase efficiency and prevent strong heating, very powerful IRLR2905 field-effect transistors with minimal resistance are used in the output stage of the device. It is possible to replace it with IRF2804, but the power of the converter will drop slightly
Using elements DD1.1 - DD1.3, C1, R1, a master generator of rectangular pulses with an approximate frequency of 200 Hz is assembled according to the standard circuit. From the output of the generator, pulses follow to a frequency divider consisting of elements DD2.1 - DD2.2. As a result, at the output of the divider (pin 6 of element DD2.1), the pulse repetition rate is reduced to 100 hertz, and at output 8 of DD2.2. The signal frequency is 50 hertz.
The rectangular signal from pin 8 of the DD1 chip and from pin 6 of the DD2 chip is supplied to the diodes VD1 and VD2, respectively. In order for the field-effect transistors to open completely, it is necessary to increase the amplitude of the signal that comes from the diode VD1 and VD2; for this, transistors VT1 and VT2 are used. With the help of transistors VT3 and VT4 (they act as a driver), the output power transistors are controlled. If no errors were made during the assembly of the inverter, then it starts working immediately after switching on. It is possible that it may be necessary to select the resistance of resistor R1 so that the output is exactly 50 hertz.
Voltage converter (inverter) 12 / 220 50 Hz 500 W DIY circuit
Silicon transistors VT1, VT3 and VT4 - KT315 with any letter. Transistor VT2 can be replaced with KT361. Stabilizer DA1 is a domestic analogue of KR142EN5A. All resistors in the circuit have a power of 0.25 W. Any diodes KD105, 1N4002. Capacitor C1 with a stable capacitance - type K10-17. As a transformer TP1, it is possible to use a power transformer from an old Soviet TV. All windings must be removed, leaving only the network winding. On top of the network winding, wind two windings simultaneously with PEL wire - 2.2 mm. Field-effect power transistors must be installed on an aluminum finned radiator with a total area of 750 sq.cm.It is recommended that the converter (inverter) be started for the first time through a household incandescent lamp of 220 volts and a power of 100 - 150 watts, connected in series to one of the supply wires, this will protect you from damage to radio components in the event of an error.
When working with boost converters or inverters, follow the electrical safety rules since the work is carried out with a voltage dangerous to the body!!! During the commissioning and assembly process, the output secondary winding must be insulated with rubber tube cambrics to avoid accidental contact.
A car voltage inverter can sometimes be incredibly useful, but most of the products in stores are either poor in quality or not satisfactory in terms of power, and are not cheap. But the inverter circuit consists of the simplest parts, so we offer instructions for assembling a voltage converter with your own hands.
Inverter housing
The first thing to consider is the electricity conversion losses released in the form of heat on the circuit switches. On average, this value is 2-5% of the rated power of the device, but this figure tends to increase due to improper selection or aging of components.
Heat removal 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.
For radiator profiles, a regular “comb” with a width of 80-120 mm and a length of about 300-400 mm is suitable. The field-effect transistor screens are attached to the flat part of the profile with screws - metal spots on their rear surface. But this is not all simple: there should be no electrical contact between the screens of all transistors in the circuit, so the radiator and fastenings are insulated with mica films and cardboard washers, while a thermal interface is applied to both sides of the dielectric spacer with metal-containing paste.
We determine the load and purchase components
It is extremely important to understand why an inverter is not just a voltage transformer, and also why there is such a diverse range of such devices. First of all, remember that by connecting a transformer to a DC source, you will not get anything at the output: the current in the battery does not change polarity, accordingly, 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 network oscillations to perform the transformation. It is usually assembled on two bipolar transistors capable of driving 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 amps, but in general you just need to multiply the current by the battery voltage to get an approximate number of watts of power output without taking into account losses.
A simple converter based on a multivibrator and power field switches IRFZ44
The operating 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 DC using a diode bridge. Such an inverter can be suitable for powering purely active loads - incandescent lamps or electric heaters, stoves.
Based on the obtained base, you can assemble other circuits that differ in the frequency and purity of the output signal. It is easier to select components for the high-voltage part of the circuit: the currents here are not so high, in some cases the output multivibrator and filter assembly can be replaced with a pair of microcircuits with appropriate wiring. Electrolytic capacitors should be used for the load network, and mica capacitors for circuits with low signal levels.
Option of a converter with a frequency generator based on K561TM2 microcircuits in the primary circuit
It is also worth noting that 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
The struggle for a sine wave - we analyze typical circuits
Voltage inverters are used everywhere today, both by 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 complexity of the converter device directly determines the width of the range of current collectors that can be connected to it.
Unfortunately, pure “sine” is present only in the main power supply network; it is very, very difficult to achieve 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 without smoothing is sufficient.
ESL, LED lamps and all kinds of current generators (power supplies, chargers) are more critical to the choice of frequency, since their operating circuit is based on 50 Hz. 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 in the inverter output circuit.
But even such a cunning plan will not work if you plan to use an inverter to provide stable power to networks with a mass of heterogeneous consumers, including asynchronous electrical machines. Here, pure “sine” is very important and only frequency converters with digital signal control can implement this.
Transformer: we’ll select it or do it ourselves
To assemble the inverter, we only need one circuit element that transforms low voltage into high voltage. You can use transformers from power supplies of personal computers and old UPSs; their windings are designed to transform 12/24-250 V and back, all that remains is to correctly determine the conclusions.
Still, it’s better to wind the transformer with your own hands, since 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 wound manually and not tightly. In addition, you can easily calculate the required number of turns and wire thickness using calculators available on the Internet.
Before winding, the core ring needs to be prepared - remove the sharp edges with a file and wrap tightly with an insulator - fiberglass impregnated with epoxy glue. Next comes the winding of the primary winding from 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 terminals are connected according to the diagram and insulated with heat shrink.
The primary winding is covered with two layers of Mylar insulating tape, then a high-voltage secondary winding and another layer of insulation are wound. An important point is that the secondary must be wound in the opposite direction, otherwise the transformer will not work. Finally, a semiconductor thermal fuse must be soldered into the gap to one of the taps, the current and response temperature of which are determined by the parameters of the secondary winding wire (the fuse body must be tightly wound to the transformer). The transformer is wrapped on top with two layers of vinyl insulation without an adhesive base, the end is secured with a tie or cyanoacrylate glue.
Installation of radio elements
All that remains is to assemble the device. Since there are not so many components in the circuit, they can be placed not on a printed circuit board, but mounted mounted to a radiator, that is, to the device body. We solder the pin legs with a solid copper wire of a sufficiently large cross-section, then the connection point is strengthened with 5-7 turns of thin transformer wire and a small amount of POS-61 solder. After the connection has cooled, it is insulated with a thin heat-shrink tube.
High-power circuits with complex secondary circuitry may require a printed circuit board with transistors lined up on the edge for loose attachment to the heatsink. Fiberglass with a foil thickness of at least 50 microns is suitable for making a signet; if the coating is thinner, reinforce the low-voltage circuits with jumpers made of copper wire.
Today it’s easy to make a printed circuit board at home - the Sprint-Layout program allows you to draw clipping stencils for circuits of any complexity, including double-sided boards. The resulting image is printed by a laser printer on high-quality photo paper. Then the stencil is applied to cleaned and degreased copper, ironed, and the paper is washed away with water. The technology is called “laser ironing” (LIT) and is described on the Internet in sufficient detail.
You can etch away copper residues with ferric chloride, electrolyte, or even table salt; there are plenty of ways. After etching, the baked-on toner needs to be washed off, drill mounting holes with a 1 mm drill and go over all the tracks with a soldering iron (submerged arc) to tin the copper of the contact pads and improve the conductivity of the channels.
Schematic diagram of the 12-220 inverter on TL494
This inverter uses a ready-made high-frequency step-down transformer from the computer’s power supply, but in our converter it will become, on the contrary, a step-up transformer. This transformer can be taken from both AT and ATX. Typically, such transformers differ only in size, and their pin locations are the same. You can look for a dead power supply (or a transformer from it) at any computer repair shop.
If you don’t find such a transformer, you can try winding it manually (if you have the patience). Here is the transformer I used in my version:
Transistors must be placed on a radiator, otherwise they may overheat and fail.
I used an aluminum radiator from a semiconductor Soviet TV. This radiator did not quite fit the size of the transistors, but I had no other option.
It is also advisable to insulate all high-voltage terminals of this inverter and it is better to assemble everything into a housing, because if this is not done, a short circuit may accidentally occur or you may simply touch the high-voltage terminal, which will be very unpleasant.
Be careful! The output of the circuit is high voltage and can cause a very serious shock.
I used a case from a laptop power supply. It fit very well in size.
And of course the inverter in action:
Good luck to everyone, Kirill.
Many radio amateurs are also car enthusiasts and love to relax with friends in nature, but they don’t want to give up the benefits of civilization at all. Therefore, they assemble a 12 220 voltage converter with their own hands, the circuit of which is shown in the figures below. In this article I will tell and show various designs of inverters that are used to obtain 220 Volt mains voltage from a car battery.
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 Amps or more are suitable for this design; I used inexpensive transistors IRFZ44/46/48, but if you need more power at the output, better use more powerful field-effect transistors.
We wind the transformer on a ferrite ring or an E50 armored core, or you can use any other one. The primary winding should be wound with a two-core wire with a cross-section of 0.8 mm - 15 turns. If you use an armored core with two sections on the frame, the primary winding is wound in one of the sections, and the secondary winding consists of 110-120 turns of copper wire 0.3-0.4 mm. At the output of the transformer we obtain an alternating voltage in the range of 190-260 Volts, rectangular pulses.
The 12 220 voltage converter whose circuit has been described can power various loads, power of which is no more than 100 watts
Output pulse shape - Rectangular
A transformer in a circuit with two primary windings of 7 Volts (each arm) and a mains winding of 220 Volts. Almost any transformers from uninterruptible power supplies are suitable, but with a power of 300 watts or more. The diameter of the primary winding wire is 2.5 mm.
Transistors IRFZ44, if missing, can be easily replaced with IRFZ40,46,48 and even more powerful ones - IRF3205, IRL3705. The transistors in the TIP41 (KT819) multivibrator circuit can be replaced with domestic KT805, KT815, KT817, etc.
Attention, the circuit does not have protection at the output and input from short circuit or overload, the keys will overheat or burn out.
Two versions of the printed circuit board design and a photo of the finished converter can be downloaded from the link above.
This converter is quite powerful and can be used to power a soldering iron, grinder, microwave oven 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 across the entire ferrite ring. After winding, we insulate the winding and begin to wind the step-up winding, 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, it should work immediately and does not require any configuration.
As with the previous design, the heart of the circuit is the TL494.
This is a ready-made push-pull pulse converter device; its complete domestic analogue is 1114EU4. High-efficiency rectifier diodes and a C-filter are used at the output of the circuit.
In the converter I used a ferrite W-shaped core from the TPI TV transformer. All the original windings were unwound, because I re-wound the secondary winding 84 turns with 0.6 wire in enamel insulation, then a layer of insulation and move on to the primary winding: 4 turns oblique from 8 0.6 wires, after winding the windings were ringed and divided in half, we got 2 windings of 4 turns in 4 wires, the beginning of one was connected to the end of the other, so we made a tap from the middle, and finally wound the feedback winding with five turns of PEL 0.3 wire.
The 12 220 voltage converter circuit that we examined includes a choke. You can make it yourself by winding it on a ferrite ring from a computer power supply with a diameter of 10 mm and 20 turns of PEL 2 wire.
There is also a drawing of a printed circuit board for a 12,220 volt voltage converter circuit:
And a few photos of the resulting 12-220 Volt converter:
Again, I liked the TL494 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 its conclusions, so be careful when choosing your placement option.
To make the case, I used a 0.25L soda can, which I had successfully snatched up after a flight from Vladivostok, cut off the top ring with a sharp knife and cut out the middle of it, and glued a circle of fiberglass with holes for a switch and connector into it using epoxy.
To give the jar rigidity, I cut a strip the width of our body from a plastic bottle, coated it with epoxy glue and placed it in the jar. After the glue had dried, the jar became quite rigid and had insulated walls; the bottom of the jar was left clean for better thermal contact with the radiator of the transistors.
To complete the assembly, I soldered the wires to the cover and secured it with hot glue; this will allow, if the need arises, to disassemble the voltage converter by simply heating the cover with a hairdryer.
The design of the converter is designed to convert 12 volt voltage from the battery into 220 volt alternating voltage with a frequency of 50 Hz. The idea for the scheme was borrowed from November 1989.
The amateur radio design contains a master oscillator designed for a frequency of 100 Hz on the K561TM2 trigger, a frequency divider by 2 on the same chip, but on the second trigger, and a power amplifier using transistors loaded by a transformer.
Taking into account the output power of the voltage converter, transistors should be installed on radiators with a large cooling area.
The transformer can be rewound from an old network transformer TS-180. The mains winding can be used as a secondary winding, and then windings Ia and Ib are wound.
A voltage converter assembled from working components does not require adjustment, with the exception of the selection of capacitor C7 with a connected load.
If you need a printed circuit board drawing made in , click on the PCB drawing.
Signals from the PIC16F628A microcontroller through 470 Ohm resistances control the power transistors, forcing them to open one by one. The half-windings of a transformer with a power of 500-1000 VA are connected to the source circuits of field-effect transistors. There should be 10 volts on its secondary windings. If we take a wire with a cross-section of 3 mm2, then the output power will be about 500 W.
The whole design is very compact, so you can use a breadboard without etching the tracks. You can catch the archive with the microcontroller firmware at the green link just above
The 12-220 converter circuit is made on a generator that creates symmetrical pulses that follow out of phase and an output block implemented on field switches, the load of which is connected to a step-up transformer. Using elements DD1.1 and DD1.2, a multivibrator is assembled according to the classical scheme, generating pulses with a repetition frequency of 100 Hz.
To form symmetrical pulses traveling in antiphase, the circuit uses a D-trigger 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 100 Hz, then the output of the trigger will be only 50 Hz.
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 travel to the field-effect transistors.
A step-up transformer is included in the drain circuits of the transistors. To protect against self-induction, high-power zener diodes are connected to the drains. RF interference suppression is carried out by a filter on R4, C3.
The winding of the inductor L1 is made by hand on a ferrite ring with a diameter of 28 mm. It is wound with PEL-2 0.6 mm wire in one layer. The most common network transformer is 220 volts, but with a power of at least 100 W and having two secondary windings of 9 V 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 arrive at a frequency divider built on elements DD2.1 - DD2.2. Therefore, at the output of the divider 6, the output of DD2.1, the frequency is reduced to 100Hz, and already at the 8th output of DD2.2. it is 50 Hz.
The signal from pin 8 of DD1 and pin 6 of DD2 goes to diodes VD1 and VD2. To fully open the field-effect transistors, it is necessary to increase the amplitude of the signal that passes from the diodes VD1 and VD2; for this, VT1 and VT2 are used in the voltage converter circuit. The field-effect output transistors are controlled through VT3 and VT4. If no errors were made during the assembly of the inverter, then it starts working immediately after power is applied. The only thing that is recommended to do is to select the value of resistance R1 so that the output is the usual 50 Hz. VT5 and VT6. When output Q1 (or Q2) goes low, transistors VT1 and VT3 (or VT2 and VT4) open, and the gate capacitances begin to discharge, and transistors VT5 and VT6 close.
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 at 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 chip.
Its outputs Q1 and Q2 will switch to the zero state and field-effect transistors VT5 and VT6 will close, causing a decrease in the output voltage.
A current protection unit based on relay K1 has also been added to the voltage converter circuit. If the current flowing through the winding is higher than the set value, the contacts of the reed switch K1.1 will operate. The FC input of the DA1 chip will be high and its outputs will go low, causing transistors VT5 and VT6 to close and a sharp decrease in current consumption.
After this, DA1 will remain in a locked state. To start the converter, a voltage drop at the input IN DA1 will be required, which can be achieved either by turning off the power or by short-circuiting capacitance C1. To do this, you can introduce a non-latching 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 designed to smooth it. The HL1 LED is necessary to indicate the presence of output voltage.
The T1 transformer is made from TS-180; it can be found in the power supplies of old CRT televisions. All its secondary windings are removed, and the network voltage of 220 V is left. It serves as the output winding of the converter. Half-windings 1.1 and I.2 are made from 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, rated for current up to 20...30 A. The wire is wound on the reed switch body with making contacts.
By selecting resistor R3, you can set the required frequency of the output voltage, and resistor R12 - the amplitude from 215...220 V.