Powerful converter 12/350 volts on IC. Scheme, description

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Schemes of radio-electronic and electrical devices

Powerful converter 12/350 volts on IC. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Voltage converters, rectifiers, inverters

Comments on the article

The master oscillator of the converter (Fig. 4.67) is assembled on a standard PWM controller (import analogue from the 494th series). The controller generates control signals for the power amplifier transistors, excluding through currents through them. "Dead time" (Dead time) is at least 3% of the duration of the oscillation period and is set by the voltage at pin 4 of the DA1 chip: at 0 V - 3%, at 3,5 V - 100%.

Powerful converter 12/350 volts on IC

The controller has two amplifiers, one of which is used to prevent battery discharge (will not allow the converter to work when the battery voltage drops below 8 V).

It is advisable to install a circuit to prevent battery discharge not only when it is a pity to ruin the battery, but also when power transistors are used without logical control, i.e. without the letter L (they have an opening threshold of 4 ... 6 V), and if the battery is strongly discharged, they can switch to active mode, which will damage the circuit due to overheating.

The conversion frequency is set by the elements C3, R8 and at the indicated ratings is 40 kHz.

To change the frequency, these elements can be changed within 500 pF ... 0,1 μF and 1 ... 100 kOhm. Converter no-load current - 70 mA, consumption under load - 5 ... 7 A at maximum load (about 100 W). The efficiency is 98%. The battery used is 12 V (10 Ah). The core of the transformer T1 is two M2000NM ferrite rings of size K32x16x9 (diameter 32 mm, cross section 1,4 cm2, 3 V per turn).

The primary winding contains 4 + 4 turns, a wire with a diameter of 0,91 mm (wound in 4 wires laid with tape). Secondary winding - 130 turns with a diameter of 0,45 mm.

As a DA1 chip, any controller from the 494 series (TL494, UC494, tsRS494, CD494, KA7500) is suitable. Transistors VT1 and VT2 can be KT645, KT3102, etc.

Field-effect transistors (not IGBT and not KP954) with a maximum voltage of at least 50 V, channel resistance <0,015 Ohm and gate capacitance <3000 pF. The IRL3705L transistors have an on-resistance R-zc of 0,01 ohms and can be replaced by two IRFZ44Ns connected in parallel (R3C = 0,022 ohms).

There are Minsk transistors from the plant "Integral" KP732G, they are better than the declared analogue IRFLZ44, their nameplate resistance is 28 mOhm, and according to measurements - 18 mOhm, and they are cheaper. Of our new ones, KP812 will do. It is advisable to use high-speed diodes VD3 ... VD6 (not fast ones get very hot at high loads), with a reverse voltage of at least 400 V, and for a current of at least 1 A.

Author: Semyan A.P.

See other articles Section Voltage converters, rectifiers, inverters.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Machine for thinning flowers in gardens 02.05.2024

In modern agriculture, technological progress is developing aimed at increasing the efficiency of plant care processes. The innovative Florix flower thinning machine was presented in Italy, designed to optimize the harvesting stage. This tool is equipped with mobile arms, allowing it to be easily adapted to the needs of the garden. The operator can adjust the speed of the thin wires by controlling them from the tractor cab using a joystick. This approach significantly increases the efficiency of the flower thinning process, providing the possibility of individual adjustment to the specific conditions of the garden, as well as the variety and type of fruit grown in it. After testing the Florix machine for two years on various types of fruit, the results were very encouraging. Farmers such as Filiberto Montanari, who has used a Florix machine for several years, have reported a significant reduction in the time and labor required to thin flowers. ... >>

Advanced Infrared Microscope 02.05.2024

Microscopes play an important role in scientific research, allowing scientists to delve into structures and processes invisible to the eye. However, various microscopy methods have their limitations, and among them was the limitation of resolution when using the infrared range. But the latest achievements of Japanese researchers from the University of Tokyo open up new prospects for studying the microworld. Scientists from the University of Tokyo have unveiled a new microscope that will revolutionize the capabilities of infrared microscopy. This advanced instrument allows you to see the internal structures of living bacteria with amazing clarity on the nanometer scale. Typically, mid-infrared microscopes are limited by low resolution, but the latest development from Japanese researchers overcomes these limitations. According to scientists, the developed microscope allows creating images with a resolution of up to 120 nanometers, which is 30 times higher than the resolution of traditional microscopes. ... >>

Air trap for insects 01.05.2024

Agriculture is one of the key sectors of the economy, and pest control is an integral part of this process. A team of scientists from the Indian Council of Agricultural Research-Central Potato Research Institute (ICAR-CPRI), Shimla, has come up with an innovative solution to this problem - a wind-powered insect air trap. This device addresses the shortcomings of traditional pest control methods by providing real-time insect population data. The trap is powered entirely by wind energy, making it an environmentally friendly solution that requires no power. Its unique design allows monitoring of both harmful and beneficial insects, providing a complete overview of the population in any agricultural area. “By assessing target pests at the right time, we can take necessary measures to control both pests and diseases,” says Kapil ... >>

Random news from the Archive

Bananas in containers 11.06.2000

One of the German shipbuilding companies handed over to the customer - the American company "Dole" two of the world's largest container ships for the transport of bananas from Costa Rica.

Each of the 205-metre-long ships carries thirty thousand tons of bananas loaded into a thousand containers (twice as many as the largest banana carriers in existence). The ship's speed is 21 knots (about 40 kilometers per hour). On the way, bananas are cooled, and the total capacity of refrigerators is about 15 megawatts.

The banana car is supplied with electricity from five diesel generators.

Other interesting news:

▪ TV Philips 55PUS9109 on Android

▪ Gold from phones

▪ Bats' immunity to transmissible viruses explained

▪ Accurate map of the ocean floor

▪ Optoma UHZ50 Smart 4K UHD Laser Projector

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ site section Power Amplifiers. Article selection

▪ article Not at ease. Popular expression

▪ article Why do clouds have different shapes? Detailed answer

▪ article Fragrant annual savory. Legends, cultivation, methods of application

▪ article A simple microcontroller programmer. Encyclopedia of radio electronics and electrical engineering

▪ article Three voltages from one Krona. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews