Simple automatic charger. Scheme, description

Free technical library

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

Simple automatic charger. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Chargers, batteries, galvanic cells

Comments on the article

The device has control and charge control units and a battery desulfation mode by charging it with a current with a discharge component. Despite all the complications, the charger remained quite simple in design, easy to set up and easy to use.

(click to enlarge)

The control unit monitors the voltage on the battery during charging, turns it off when it is fully charged and signals this by turning on the LED.

The desulfation mode allows in some cases to restore the capacity of batteries, the operation of which did not fully comply with the established rules. In this mode, the constant charging current is replaced by a charge-discharge current. The ratio of charging and discharging current in this mode is 10:1. This mode can also be useful in the prevention of good batteries.

The charging pulsating current supplied to the battery is taken from the secondary winding of the step-down transformer T1. In normal mode, the triac VS2 opens in both half-cycles of the AC mains voltage. Resistor R3, which is part of the control unit, can regulate the charging current within certain limits.

With a heavily discharged battery, the current can reach 5 A, decreasing as it charges up to 1 A, while the voltage, on the contrary, increases to 15,8 ... 16,2 V, which makes it possible to fix the moment the charging process ends. The control unit is made on the comparator DA1. The comparator threshold is set by a variable resistor R12.

As soon as the voltage on the battery exceeds the threshold, the comparator will switch and a high voltage will appear at its output. As a result, thyristor VS2 will open and relay K1 will operate. With contacts K1.1, it will open the control circuit of the powerful triac VS1, it will close and de-energize the load.

Contacts K1.2 of the relay will turn on the LED "END OF CHARGE" HL2, indicating that the battery is charged, and K1.3 open the circuit of the discharge resistor R8. The "NETWORK" HL1 LED lights up only when the T1 transformer is connected to the network, and the "READY" HL3 indicator lights up, indicating that the battery is connected to the device in the correct polarity and it is not too discharged.

The charger protects fuse F2 from connecting the battery in reverse polarity.

If the battery is disconnected for any reason during charging, the voltage at the positive load terminal will increase, which will trigger the DA1 comparator. Therefore, the triac VS1 will immediately close and the HL2 LED will turn on.

The desulfation mode is switched on by the SA2 toggle switch. In this case, contacts SA2.1 open and SA2.2 closes. The triac will turn on only for half the period of the mains voltage, and during the second half-cycle, a discharge current will flow through the battery and resistor R8. The triac works as a rectifier in this mode, and the diode bridge VD3 -4 VD6 only provides the necessary polarity of the charging voltage.

After the automation unit is triggered and the battery is charged, it will be loaded with the HL3 LED circuit. Despite the completely insignificant current through this LED, it is better to immediately disconnect the charged battery from the charger. If timely shutdown cannot be ensured, in series with the battery, at point A, a powerful diode (for example, D242A) should be turned on with the cathode towards the bridge VD3 - VD6.

In order to reduce the tendency of the comparator to "bounce" near the trigger zone, a capacitor C3 is connected to its inputs (pins 4 and 3). The capacitance must be determined experimentally (starting from 10 pF).

When the charger is turned on, in the absence of a rechargeable battery, the HL2 LED "END OF CHARGE" turns on. This is not a sign of a malfunction of the device, but the result of an increase in voltage at its output without load. As soon as the battery (discharged) is connected to the charger, the LED will turn off.

Device setup

Setting up the charger consists in setting the voltage to 8 V at pin 3 of the DA1 comparator.

Details

Transformer T1 must have a power of at least 160 watts.

The triac can be any for a current of at least 10 A. It is advisable to install it on a heat sink with a useful area of \u100b\uXNUMXbabout XNUMX cm. Powerful diodes should also be equipped with heat sinks.

Relay K1 - RES22, passport RF4.500.13Sh2. It can be replaced by the RES9 relay, passport RS4.529.029-11, while the R6, HL2 circuit must be connected in parallel with the K1 relay winding.

Author: Shelestov I.P.

See other articles Section Chargers, batteries, galvanic cells.

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

Office building could be 3D printed 16.07.2015

Dubai could be the city with the world's first 3D printed office building. The unusual project is meant to stimulate the development of a technology that, over time, could become a fast and cost-effective way to build buildings.

Volumetric printing technologies that allow the formation of material objects based on computer drawings are becoming increasingly popular in various industries, but they are not yet widespread in construction.

A one-story building in Dubai with an area of approximately 185 m2 will be printed in layers using a printer approximately seven meters high. Then, within a few weeks, the layers will be collected at the permanent location of the building. Furniture and interior elements will also be 3D printed. Reinforced concrete, reinforced gypsum and plastic will be used as materials.

The project is a joint brainchild of the city authorities and the Chinese company Winsun, which specializes in the use of 3D printing in construction. The use of 3D printing is said to reduce construction time by 50-70% and labor costs for builders by 50-80%.

Other interesting news:

▪ The main reason for being overweight

▪ Electrical Brain Stimulation Improves Cognitive Ability

▪ Video camera for animals with built-in feeder

▪ Scottish Atlantis

▪ Restarting the Large Hadron Collider

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Funny puzzles. Article selection

▪ article Bloch to shoe. Popular expression

▪ article What French word, being in Russian, was borrowed back by the French? Detailed answer

▪ Article Assistant to the head of the enterprise. Job description

▪ article Bandwidth Throttling. Encyclopedia of radio electronics and electrical engineering

▪ article Scheme, pinout (pinout) of the Sagem 6xx, 7xx, 8xx cable. 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