Anode voltage indicator. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Measuring technology
Comments on the article
This simple indicator was designed to determine the presence and approximate value of voltage at the output contacts of a laboratory voltage source used to power the anode circuits of radio tubes.
After adjusting the values of some elements, this device can be used to indicate the on state of any devices powered by batteries with a voltage of 9 V to 12 V (not tested). It uses a high emissivity LED as an indicator, which periodically generates intense flashes of light.
At an input voltage of 20 V, the frequency of flashes is approximately 1 s (frequency 1 Hz), with increasing voltage, the period of light pulses decreases and at 250 V it is about 0,2 s (frequency 5 Hz). The input current of the indicator is small - from 0,11 mA at an input voltage of 20 V to 1,53 mA at 250 V.
Schematic diagram of the anode voltage indicator is shown in fig. one.
Rice. 1 (click to enlarge)
The operation of the proposed indicator is based on the principle of charge accumulation. Capacitor C1 is charged from a source of indicated voltage with a small current through resistors R1, R2 and diode D1. The voltage from the capacitor C1 through the divider R3, R4 is supplied to the base of the transistor T1. When the voltage on the capacitor C1 reaches a value of approximately 6 V, the transistor T1 ensures the opening of the transistor T2. As a result, capacitor C1 is discharged through transistor T2 and LED D1. After the capacitor C1 is completely discharged, both transistors close, and the capacitor C1 starts charging again.
The details of the indicator are placed on a single-sided printed circuit board. The printed circuit board (a) and the location of the elements (b) of the anode voltage indicator are shown in fig. 2.
Fig. 2
In order for the design to be small, SMD elements are used. The printed circuit board of the indicator can be placed on the rear panel of the device whose supply voltage is to be measured. Assembled without errors and from serviceable elements, the indicator does not require adjustment.
See other articles Section Measuring technology.
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 Fasten your seat belts, backseat passengers
15.07.2002
After studying one hundred thousand car accidents, the Japanese scientist Macao Ichikawa came to the conclusion that passengers in the rear seats should definitely wear seat belts.
In a head-on collision, the front passenger and driver are six times less likely to die if the rear passengers are buckled up. If not, inertia throws them forward. At a speed of 50 kilometers per hour and with an average Japanese weight of 70 kilograms, the push can be fatal for those sitting in front.
Now seat belts are mandatory in only 14 countries around the world.
|
Other interesting news:
▪ Bad sleep hurts love
▪ A supercapacitor is 5 times thinner than a sheet of paper
▪ Antibiotics from cannabis
▪ TV on the wrist
▪ Thinness genes
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ section of the site Consumer Electronics. Selection of articles
▪ article Tripods: what we stand on. video art
▪ article When did you start milking cows? Detailed answer
▪ article Muretia fragrant. Legends, cultivation, methods of application
▪ article The second wind of the refrigerator. Encyclopedia of radio electronics and electrical engineering
▪ article Coin and hat. 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