Pulse charger for NiCd batteries. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Chargers, batteries, galvanic cells
Comments on the article
Widespread small-sized NiCd and NiMH batteries have a "memory effect", i.e. loss of capacity during incomplete discharge and subsequent charging.
To eliminate it, it is recommended to completely discharge the cell to a voltage of 1 V and then charge it with current pulses that have a negative (discharge) component. We offer a small-sized charger and recovery device for one NiCd cell.
The required power of the transformer T1 to charge one battery is 1 ... 3 W. The phase regulator of the charging current is connected to the transformer T1 through a half-wave rectifier on the diode VD1 and contains the transistor VT1, the phase shifter R2-C1, and the diode VD2, which increases the threshold of the regulator. This is followed by a composite emitter follower (power amplifier) on transistors VT2, VT3. From the emitter VT3, the charging current enters the element G1.
The level of charging current is controlled by the simplest pointer microammeter RA1, shunted with a low-resistance resistor R6 to obtain the desired measurement limit. With the help of a variable resistor R7 and a diode VD3, a negative current pulse is formed in the corresponding half-cycle of the mains voltage.
The SA2 toggle switch turns on the negative component of the charging current after setting the main charging current. The charging current is taken equal to 0,1C (C is the nominal capacity of the battery). After turning on the negative component, the charging current should decrease by 10%. This value is set by the resistor R7. Charging time is 12...15 hours.
Authors: Ya.Partin, L.Partina, Yekaterinburg
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 Self-driving Volvo cars with all-round visibility
01.03.2015
Volvo's self-driving cars, recently introduced by the company, have the means to provide precise location and a full 360° view. These are radars, cameras and laser sensors. A duplicated network of computers processes information, forming a map in real time, which displays moving and stationary objects around the car. The pinpoint location feature uses information about objects around the vehicle, as well as GPS data and a high-resolution XNUMXD digital map that is constantly updated with real-time data. The system is quite reliable and does not require driver control.
The 76 GHz continuous-wave radar and camera are mounted on the windshield - exactly the same solution used in the new Volvo XC90. This system reads road signs and monitors road bends, detects other road users and other objects on the road.
The front and rear bumpers are chosen to house four radar antennas capable of detecting objects in all directions. Radars cover 360°. The same angle, that is, a circular view is provided by four cameras, the task of which is to monitor objects in the immediate vicinity of the car. Two cameras are installed under the exterior mirror housings, the third - in the rear bumper, the fourth - in the grille. These cameras also monitor road markings. The manufacturer notes that the large dynamic range allows the cameras to quickly adjust to changing lighting, for example, when entering and exiting a tunnel.
At the front of the vehicle, under the air intake, there is a multi-beam laser scanning sensor. Its field of view is 140°, the range is 150 m. The sensor allows you to detect and recognize objects in front of the car.
A three-focus camera is installed at the top of the windshield. This is essentially three cameras in a single body: one with a wide 140° field of view, another with a 45° field of view, and a third long-range camera with a narrow 34° field of view, which is necessary for more accurate depth perception and distance estimation. objects. The camera is able to detect suddenly appeared on the road pedestrians and other dangerous objects.
The space behind the car is monitored by long-range radars. There are two of them and both of them are installed in the rear bumper. Their readings are used for vehicles approaching from behind. They are important, for example, when changing lanes.
When driving at low speeds, twelve ultrasonic sensors around the perimeter of the car come into play. They resemble the sensors of existing parking assist systems, but they use a more advanced signal processing system. Ultrasonic sensors are most relevant in situations where a pedestrian or other object suddenly appears near the car.
Using a high-resolution XNUMXD digital map, the vehicle obtains information about the environment, including elevation, road curves, lane count, tunnel geometry, guardrails, signs, ramps and more. In many cases, positioning is taken into account with an error measured in centimeters.
The operation of the vehicle location system is based on the indications of GPS, a three-axis accelerometer and a gyroscope. By comparing the images received from cameras and sensors with the image on the map, the car accurately determines its location in relation to surrounding objects. This allows you to choose the best route in real time, taking into account variables, including road bends, speed limits, sign coverage, and other factors that affect traffic flow.
|
Other interesting news:
▪ Urbanista Phoenix TWS earbuds with built-in solar battery
▪ Transformer on vegetable oil
▪ Pocket cinema
▪ Biodegradable sneakers
▪ Ozone on Venus
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ site section Parameters of radio components. Article selection
▪ article Hydroelectric power plant. History of invention and production
▪ article Where was the custom of self-immolation of women spread? Detailed answer
▪ Article Common basil. Legends, cultivation, methods of application
▪ article solar energy. Impact on the economy, ecology and employment of the population. Encyclopedia of radio electronics and electrical engineering
▪ article Voltage stabilizer with double protection, 40/3-30 volts 2 amps. 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
www.diagram.com.ua
2000-2024
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese