Improvement of the electronic voltage stabilizer. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Automobile. Batteries, chargers
Comments on the article
It has been established that the battery lasts more reliably and longer if the regulator of the electrical system maintains the on-board voltage, which varies depending on the temperature. Serial automotive equipment cannot provide this.
The author of the published article managed to obtain, by simple means, the temperature coefficient of the onboard voltage close to the optimum.
The disadvantage of domestic electronic automotive voltage stabilizers, in particular, mass-produced Ya112 and Ya120. is that they do not provide the necessary temperature dependence of the onboard voltage [1; 2].
On fig. 1 shows a typical diagram of a traditionally built voltage regulator threshold assembly. The law of change of the stabilized voltage here mainly determines the silicon zener diode VD1, and it does not correspond to the solution of the problem either in value or in sign of the temperature coefficient of the stabilization voltage.
This leads to the fact that the electrolyte in the battery boils in summer, and in the cold season it remains undercharged.
I propose to build the voltage stabilizer threshold node a little differently (Fig. 2). In this embodiment, the transistor VT1 still serves as the threshold element, and the stabistor VD1 operates in the standard mode provided by the resistor R4. It is easy to see that the current through the stabistor depends little on the base current of the transistor.
At voltage Upit. less than the set one, the transistor is closed by a voltage drop across the stabistor. When the voltage Upit, increasing, reaches the set value, the voltage at the base will be sufficient to open the transistor.
With the described version of the threshold assembly, a sample of an on-board voltage stabilizer for a passenger car was made and tested. The scheme of the device is shown in fig. 3. The stabilizer was installed on the generator 29.3701 instead of the dismantled R112.
While the onboard voltage is low, the transistor VT1 is closed, and VT2 is open. Current flows through the excitation winding of the generator. therefore, the voltage Upit increases. As soon as it exceeds the threshold level, the transistor VT1 opens, and VT2 closes - the voltage begins to decrease until the transistor VT1 closes.
The electrical "hysteresis" required for stable operation of the stabilizer for switching transistors in the stabilizer is obtained automatically due to the non-zero resistance of the connecting conductors. For this reason, the R1R2 input voltage divider should not be connected directly to the battery terminal, as is often recommended to improve voltage stability.
Diode VD2 is designed to reliably close the transistor VT2 when the transistor VT1 is open. Diode VD3 extinguishes voltage surges of self-induction of the excitation winding of the generator when the transistor VT2 is closed.
The stabilizer is assembled on a printed circuit board made of foil fiberglass with a thickness of 1,5 mm. The drawing of the board is shown in fig. 4. Transistor KT829A can be replaced by KT890A.
The required switching voltage of the stabilizer is set when adjusting the selection of resistor R2. The adjustment process has been repeatedly described in the journal (for example, in [3]), so it is omitted here. With a properly adjusted stabilizer at a temperature of +40 ° C, the voltage supported by the generator is 13,6 V. and at -20 ° C - 14,5 V.
Tests showed that the voltage instability did not exceed ±1.5%. For a stabilizer with a traditional threshold node, this figure reached ± 5%.
The best results in the operation of the stabilizer can be achieved by providing thermal contact between the transistor VT1 and the stabistor VD1 with one of the side walls of the battery.
Literature
- Lomanovich V. Thermally compensated voltage regulator. - Radio, 1985. No. 5. p. 24 - 27.
- Biryukov S. A simple thermally compensated voltage regulator. - Radio, 1994. No. 1.p.34,35: No. 10, p. 43.
- Korobkov A. Automotive voltage regulator. - Radio, 1986. No. 4, p. 44,45.
Author: V. Dobrolyubov, Korolyov, Moscow region.
See other articles Section Automobile. Batteries, chargers.
Read and write useful comments on this article.
<< Back
Latest news of science and technology, new electronics:
Artificial leather for touch emulation
15.04.2024
In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>
Petgugu Global cat litter
15.04.2024
Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>
The attractiveness of caring men
14.04.2024
The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>
| Random news from the Archive Pregnancy and childbirth changes a woman's brain
26.12.2016
Scientists from the Autonomous University of Barcelona (Spain) have shown how the structure of a woman's brain changes during pregnancy. It also turned out that the changes persist for two years after the birth of a child - perhaps longer.
The authors of the work, using magnetic resonance imaging, compared the brain structure of 25 women before and after their first pregnancy. As controls, brain scans were also taken by their male partners, as well as another 20 women who were not pregnant, and their partners.
Among the results of the study, a reduction during pregnancy of the gray matter of the brain in the medial frontal and posterior cortex, as well as in certain areas of the prefrontal and temporal cortex in pregnant women was recorded. Scientists believe that this is a picture of adaptation to future motherhood. "These changes may reflect, at least in part, the mechanism of synaptic pruning that is also characteristic of adolescence - weak synapses disappear, giving way to more efficient and specialized neural connections," explained Elseline Hoekzema, one of the authors of the work.
The researchers showed that gray matter contraction affected areas of the brain that were active during functional neuroimaging, during which mothers were shown pictures of their babies. According to scientists, these zones are associated with processes involved in social cognition and self-awareness.
The researchers did not observe any changes in memory or other functions during pregnancy, so the loss of gray matter does not imply any cognitive impairment, but only speaks of actual adaptive processes.
|
Other interesting news:
▪ Barrier for rodents
▪ Metals in champagne
▪ Strength sports are not suitable for children
▪ Nanocooling
▪ Convert infrared light to image
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ section of the site Children's scientific laboratory. Article selection
▪ article Staircase-wonderful. Popular expression
▪ article What is Wall Street? Detailed answer
▪ Manicurist article. Job description
▪ article Device for searching for biologically active points. Encyclopedia of radio electronics and electrical engineering
▪ article Overturning bottles. Focus secret
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