Menu English Ukrainian russian Home

Free technical library for hobbyists and professionals Free technical library

Free library / Schemes of radio-electronic and electrical devices

Universal power supply, 2-300 volts 0,9 amps (2-22 volts 6 amps). Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Power Supplies

Comments on the article Comments on the article

Every radio amateur knows: one cannot do without a source of constant and alternating voltages of various values ​​in practical work. It is needed to set up radio structures, repair equipment, charge batteries, test electric motors and relays, and conduct physical experiments. All this can be done using a universal power supply, the description of which we bring to the attention of readers.

The device allows you to receive smoothly varying voltages in the range of 2-300 V up to 900 mA AC and 600 mA DC or 2-22 V at a current of up to 6 A.

Universal power supply, 2-300 volts 0,9 amps (2-22 volts 6 amps)
Rice. 1. Schematic diagram of the power supply (click to enlarge)

Using switch S6 (Fig. 1), the power supply mode is set to five positions, as indicated by the corresponding lamps H1-H5.

The voltage in the range of 2-22 V is selected in steps of 2 V by switching S4, and in the range of 2-300 V - S3 through 26 V.

Toggle switch S2 transformer T1 is transferred to autotransformer mode to power more powerful current consumers.

Alternating current is converted to direct bridge rectifiers on diodes V1-V4 and V5-V8. To exclude the possibility of failure of the filter C1, V9, C2, a toggle switch S5 is installed, which must be in the "off" position when the high-voltage load is disconnected.

Rectifier V1-V4 operates in universal mode. In the fourth position of switch S6.1, a voltage of 2-22 V is supplied. In the third position of S6.1, with the toggle switch S5 closed, the high-voltage winding of the transformer is connected to the bridge.

The rectified voltage in the 2-300 V mode from the filter C1, V9, C2 is supplied to the output terminals of the power supply. In the 2-22 V mode, a constant voltage is supplied to the second filter, made on transistors V12, V13.

The rectifier on diodes V5-V8 is connected to T1 permanently.

The values ​​of voltages and currents are controlled by two pointer indicators PV1 and PA1. The ammeter scale has two measurement limits: 0-900 mA and 0-6 A. To measure currents up to 90 mA, the S7 toggle switch includes an additional shunt that divides the instrument readings by 10.

Construction and details. Perhaps the most time-consuming process is the manufacture of a transformer. TS-180-2 is taken as a basis - a power transformer from black-and-white TVs. It has a tape magnetic circuit SL21X45 made of steel E-310-0,35.

The transformer is disassembled, secondary and additional network windings of 58 turns are wound from its frames (pins 2-3). And the network windings of 375 turns of wire PEV-1 0,69 (pins 1-2) are left unchanged. Then, on one of the frames, sections XXII-XVII, XII, XI, X, IV, III, II (563 turns) are placed in the indicated sequence, on the second - XVI-XIII, IX-V (508 turns).

Sections II to XI contain 96 turns each, and XII has 34 turns of PEV-1 0,69 wire. The winding of ХХШ-XIII is wound with PEV-1 wire 1,5, 7 turns in each section. It can be wound with two wires of a smaller cross section, for example, PEV-1 0,74.

Each winding row is insulated with 2-3 layers of oiled transformer paper. The conclusions are soldered to the petals located on the frames and marked.

Between the joints of the U-shaped halves of the tape magnetic core, if necessary, lay 2-3 layers of capacitor paper so that the gap is 15-30 microns. Then the "buzz" of the transformer will become much weaker. After completing the assembly, connect the network windings together as shown in the diagram.

Transistors and diodes D242 are mounted on heat sinks (see Fig. 2) - an aluminum plate 90X50X1 mm in size for the first and two aluminum plates 2 mm thick stacked together for the second.

Universal power supply, 2-300 volts 0,9 amps (2-22 volts 6 amps)
Rice. 2. Power transformer with installed elements: 1 - heat sink for D242 diodes, 2 - heat sink for transistors, 3 - panel with KD202M diodes, 4 - panel with resistors R3-R6, 5 - getinax board.

Instead of the P4BE transistor, it is permissible to use GT701A, P209, P210, and instead of P201, P213, P214, P216, P217 with any letter index are suitable. Diodes KD202M can be replaced with KD202K, KD202L or D226B, KD105, connected two in parallel; D242 - on KD206 with any letter index or D243, D244, D245; D9E - any series D2 or D9.

Capacitors C1, C2 K50-12 have a common housing. They can be replaced with any others with an operating voltage of at least 350 V. Instead of capacitors K50-6 (C3, C4), K50-3 can be used. Fixed resistors MLT-1 or VS-1.

S1 - push-button switch from household electrical appliances, S2 - toggle switch TP-1-2, S3, S4, S6 - toggle switches, S5, S7 - toggle switches TV2-1.

PV1 - voltmeter Ts4200 with a full deflection current of the arrow 250 μA, RA1 - M4207 microammeter with a full deflection current of 50 μA. These measuring devices can be replaced by any other within the specified sensitivity. Indicator scales are made independently in accordance with the general drawing.

Shunts R7, R9, R10 are wound with nichrome wire Ø 0,3 mm on the cases of resistors BC-0,5 with a conductive layer previously removed. The shunt resistor R0,15 is also wound with the same wire, but Ø 11 mm. Shunts R8 and R12 are pieces of nichrome wire Ø 0,7 mm and 2-3 cm long. Nichrome wire can be replaced with manganin or constantan, but then the winding length will need to be doubled, since the resistivity of these materials is less. Shunts are installed on switch S6.

H1-H5 - KM 2 switching lamps are designed for a voltage of 24 V. They can be replaced with any others by removing the appropriate voltage from the transformer.

The power supply unit is housed in a duralumin case measuring 190X180X125 mm. In its side walls, 7-8 longitudinal ventilation slots 80x2 mm in size are made, and in the base - 2-3 holes Ø 20 mm.

The unit does not have a special chassis. The supporting elements are the front panel and the power transformer. Installation is made with stranded wires assembled in bundles.

The front panel measuring 180x170 mm is made of sheet duralumin 2 mm thick. A sheet of whatman paper with inscriptions made in black ink is superimposed on it, and covered from above with plexiglass 2 mm thick.

Pushbutton switch S1 is mounted on top of the housing.

If the installation is done correctly and all parts are in order, the power supply starts working immediately after it is connected to the network. It will be necessary to adjust only the values ​​​​of additional resistors and shunts for dial indicators.

Author: A.Medvedev

See other articles Section Power Supplies.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Blinking of the magician and his audience 19.05.2024

Magic and illusions have always captured the attention of the public, but what happens behind the scenes of the magician and in the brains of his audience? Scientists from the UK decided to solve this mystery by conducting a new study involving ten illusionists of varying experience. Illusionists, some of whom had been practicing magic for more than half a century, others for only six months, were invited to demonstrate the same trick - the popular coin trick. Recordings of their performances during training and on stage showed that each of them began to blink significantly more often at the moment of performing the trick. The study's findings indicate that magicians' blink rate may be related to unconscious aspects of their performance. At the same time, as scientists have found, spectators also begin to blink more often, following the movements of the illusionist. This observation supports the idea that magicians may be catalysts for blinking in audiences. Additional research has shown that magicians blink more often during ... >>

Ultrasonic coffee machine 19.05.2024

Iced coffee has become an integral part of coffee culture in recent years. Therefore, engineers from the University of New South Wales decided to improve its preparation. They have developed an ultrasonic coffee machine that reduces the cold brew time for ground coffee beans from 12-24 hours to significantly less time. Iced coffee, or "Cold brew", is popular due to its smoothness, low acidity and low bitterness. It is prepared by steeping ground coffee in cold water for a long time. Unlike traditional hot brewing, which often imparts bitterness to coffee, cold brewing extracts more delicate and complex flavors from the coffee beans. The innovative system, presented by a team of engineers, introduces ultrasonic technology into the coffee preparation process. The system uses ultrasonic waves to speed up the process of extracting oils, flavor and aroma from ground coffee. This allows you to significantly reduce the time ... >>

The speech of sperm whales is similar to that of humans 18.05.2024

In the world of the ocean, where the mysterious and unknown coexists with the studied, sperm whales, with their huge brains, are of particular interest to science. Researchers, working with a huge array of audio recordings collected during the Dominica Sperm Whale Project (DSWP) - more than 8000 recordings, seek to unravel the secrets of their communication and understand the structure and complexity of the language of these mysterious creatures. By studying in detail the recordings of 60 sperm whales in the eastern Caribbean, scientists have revealed surprising features of their communication, revealing the complexity of their language. "Our observations indicate that these whales have a highly developed combinatorial communication system, including rubato and ornaments, which indicates their ability to quickly adapt and vary during communication. Despite significant differences in evolution, sperm whales have elements in their communication that are characteristic of human communication," says Shane Gero, a biologist at Carleton University and director of the CETI project. Issl ... >>

Random news from the Archive

Atomic clocks confirm the theory of relativity 22.03.2019

The reliability of watches is supported by a principle known as Lorentz symmetry. This principle was the basis for Einstein's special theory of relativity, which describes the physics of travelers traveling at nearly the speed of light.

Lorentz symmetry states that the rules of physics should remain the same whether you are standing still or moving at breakneck speed, and no matter which direction you are oriented. The clocks kept running together as the Earth rotated, supporting this idea.

Two ytterbium ions - positively charged atoms - absorbed and emitted light at a certain frequency, functioning like a ticking clock hand. The ions, oriented in different directions, rotated as the Earth rotated, making a complete cycle every day. If the ticking of atomic clocks changed depending on their orientation in space, the experiment would show a daily change in the relative frequencies of two clocks - a violation of Lorentz symmetry. But the atomic clocks converged within one tenth of a quadrillionth of a percent, about 100 times the accuracy of previous Lorentz symmetry tests.

Other interesting news:

▪ New synchronous boost converter chipsets

▪ Processors Intel Xeon E5-2600/1600 v3

▪ Lunar ark for biomaterials

▪ World record for underwater life set

▪ A useful variety of corn for popcorn has been developed

News feed of science and technology, new electronics


Interesting materials of the Free Technical Library:

▪ section of the site Home workshop. Article selection

▪ article Signs of the times. Popular expression

▪ article Why do we perceive our voice in a recording differently than when we speak? Detailed answer

▪ article Concrete worker. Job description

▪ article Garland switch on one trinistor. Encyclopedia of radio electronics and electrical engineering

▪ article Rechargeable galvanic cells. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:


Email (optional):

A comment:

All languages ​​of this page

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