Two options for turning on the flashing LED. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Beginner radio amateur
Comments on the article
Flashing LEDs are becoming increasingly popular with radio amateurs. I offer two options for their inclusion.
In the first variant (Fig. 1), the flashing HL4 LED is connected in series with three ordinary ones (HL1-HL3) and is the "leading" one for them. Now regular LEDs will flash in sync with blinking.
Flashing LED - imported red glow, its diameter is about 5 mm. The rest of the LEDs, it is desirable to choose with the same brightness, not necessarily the same glow color. If one of them shines noticeably brighter than the others, it is shunted with a resistor of several hundred ohms (R2).
The number of conventional LEDs, if desired, can be reduced, while it is necessary either to reduce the supply voltage, or to install a larger resistor R1. By the way, this resistor is selected so that the current through the LEDs in the on state does not exceed 20 mA.
Having made several of these garlands, you can hang them on a miniature tabletop Christmas tree.
In another variant (Fig. 2), a two-phase generator of light pulses is obtained. When the flashing HL2 LED is not lit, the voltage at its terminals is maximum, the current through it is minimal, so the HL1 LED is also not lit.
The voltage between the negative power wire and the left terminal of the resistor according to the circuit increases, the stabistor VD1 opens, which leads to the flashing of the LEDs HL3, HL4.
As soon as the flashing LED turns on, the HL1 LED lights up. The voltage on the left output of the resistor according to the circuit decreases, the stabistor closes, the LEDs HL3, HL4 go out. Thus, the left and right LED strings flash alternately.
The stabistor can be replaced with three or four low-power silicon diodes, for example, KD103A, KD522A, connected in series. The number of diodes should be such that the LEDs of the right string go out when the LEDs of the left string flash. As in the previous case, the resistor must be of such a resistance that the current through the LED strings does not exceed 20 mA.
Author: A.Butov, village of Kurba, Yaroslavl region
See other articles Section Beginner radio amateur.
Read and write useful comments on this article.
<< Back
Latest news of science and technology, new electronics:
A New Way to Control and Manipulate Optical Signals
05.05.2024
The modern world of science and technology is developing rapidly, and every day new methods and technologies appear that open up new prospects for us in various fields. One such innovation is the development by German scientists of a new way to control optical signals, which could lead to significant progress in the field of photonics. Recent research has allowed German scientists to create a tunable waveplate inside a fused silica waveguide. This method, based on the use of a liquid crystal layer, allows one to effectively change the polarization of light passing through a waveguide. This technological breakthrough opens up new prospects for the development of compact and efficient photonic devices capable of processing large volumes of data. The electro-optical control of polarization provided by the new method could provide the basis for a new class of integrated photonic devices. This opens up great opportunities for ... >>
Primium Seneca keyboard
05.05.2024
Keyboards are an integral part of our daily computer work. However, one of the main problems that users face is noise, especially in the case of premium models. But with the new Seneca keyboard from Norbauer & Co, that may change. Seneca is not just a keyboard, it is the result of five years of development work to create the ideal device. Every aspect of this keyboard, from acoustic properties to mechanical characteristics, has been carefully considered and balanced. One of the key features of Seneca is its silent stabilizers, which solve the noise problem common to many keyboards. In addition, the keyboard supports various key widths, making it convenient for any user. Although Seneca is not yet available for purchase, it is scheduled for release in late summer. Norbauer & Co's Seneca represents new standards in keyboard design. Her ... >>
The world's tallest astronomical observatory opened
04.05.2024
Exploring space and its mysteries is a task that attracts the attention of astronomers from all over the world. In the fresh air of the high mountains, far from city light pollution, the stars and planets reveal their secrets with greater clarity. A new page is opening in the history of astronomy with the opening of the world's highest astronomical observatory - the Atacama Observatory of the University of Tokyo. The Atacama Observatory, located at an altitude of 5640 meters above sea level, opens up new opportunities for astronomers in the study of space. This site has become the highest location for a ground-based telescope, providing researchers with a unique tool for studying infrared waves in the Universe. Although the high altitude location provides clearer skies and less interference from the atmosphere, building an observatory on a high mountain poses enormous difficulties and challenges. However, despite the difficulties, the new observatory opens up broad research prospects for astronomers. ... >>
| Random news from the Archive Keyboard and mouse are the best indicators of stress
21.04.2023
Scientists at the Swiss Federal Institute of Technology in Zurich (ETHZ) have conducted a new large-scale study, the results of which show that exactly how we interact with the keyboard and mouse can tell a lot about our stress levels. Moreover, the researchers believe that this method is even more effective than tracking heart rate.
At the first stage, scientists conducted a study in which 90 people took part. They were asked to perform simple office tasks such as scheduling appointments, recording data, and doing data analysis. The participants were also divided into two groups - some worked unhindered, while others were distracted by chat messages or asked to interrupt for meetings.
During the study, the scientists also observed the behavior of the recipients - recorded their interaction with the mouse and keyboard, tracked their heart rate, and also asked how tense they were.
The scientists later used the data and machine learning to develop a new model for measuring job stress based on how people type and interact with the mouse. According to study author and mathematician Mar Neguelin, he and his colleagues found that the way we type and move the mouse can actually be an effective indicator of work stress levels, even better than heart rate.
The results of the study indicate that people suffering from chronic stress, as a rule, move the mouse pointer more often and less accurately; cover large distances on the screen with the mouse pointer; errors are more often made when typing; write in fragments with many short pauses. At the same time, calmer people also make pauses in typing, but there are much fewer of them, and the pauses in typing themselves are longer and more thoughtful.
According to study co-author, psychologist Jasmine Kerr, this relationship between stress levels, keyboard and mouse can be explained using the so-called neuromotor noise theory. The fact is that high levels of stress have a negative impact on our brain's ability to process information, as well as our motor skills.
Researchers now estimate that one in three workers in Switzerland suffers from workplace stress, so effective ways to detect increased stress need to be developed. Scientists note that usually a tired person cannot understand that his resources, both physical and mental, are being depleted until it is too late.
|
Other interesting news:
▪ Brain in a test tube
▪ The human brain is connected to the internet
▪ Magnetic spray creates robots
▪ Transmission of electricity from space to Earth
▪ Sex problems on Mars
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ section of the site Data transfer. Article selection
▪ article General Frost. Popular expression
▪ What was the Tower of Babel made of? Detailed answer
▪ article Warty euonymus. Legends, cultivation, methods of application
▪ article Treatment and finishing of sheepskins after drying. Simple recipes and tips
▪ article Scheme, pinout (pinout) of cable for Motorola d520, m3100 phones. 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