Electronic volume control on the KA2250 chip. Encyclopedia of radio electronics and electrical engineering

Encyclopedia of radio electronics and electrical engineering / Tone, volume controls

 Comments on the article

Hi all. Tired of spinning? Want to press? No problem. Now I will tell you how to make a push-button two-channel volume control on just one chip. There is such a Korean office - Samsung. This office produces unremarkable household crafts like mobile phones and tanks. But they also have something nice to offer. This time it is the KA2250 chip.

The microcircuit is an electronic volume control with the following parameters:

Adjustment range, dB 0…66
Adjustment step, dB 2
Operating frequency band, Hz 20…20000
Harmonic coefficient, % 0,005
Supply voltage, V 3…16

Schematic

(click to enlarge)

No, no, no need to be scared - I said - Koreans. They, apparently, have their own, specific idea of ​​​​the convenience of the location of the pins of the microcircuit and the topology of the circuit. Well, okay - the main thing is not too many attachments, so the chance to get confused is still reduced. Actually, there is nothing special to describe - we give a signal to the corresponding conclusions, everything is regulated by two buttons - S1 and S2.

Since our brothers in mind did not provide non-volatile memory in the microcircuit, one could conclude that the volume would have to be set anew every time the circuit was turned on. But no - they got out of this situation in their own way, in Korean. When the power is turned on, the capacitor C9 is charged. As soon as the power is lost and the log level leaves the output of the 7th microcircuit. 1, the microcircuit immediately blocks all its inputs and outputs and switches to the nanocurrent consumption mode. At the same time, she takes them, of course, from the capacitor C9. To be honest, I don't know how long such a system will be able to keep it all in working order. Perhaps this is just protection against short-term interruptions in the power supply.

Plate with a list of elements

Added from forum

I found this circuit and the question arises: when there is a “plus” on the 7th output relative to zero (the one on 4 and 13), then the mikruha works properly. But in this circuit, the resistor divider R3 and R1 are connected so that the resistance of R1 is less, and it is connected to the minus of the power supply, that is, there will be a minus on the 7th output relative to zero, the mikruha is blocked. Shouldn't these resistors be swapped?

Answer: You put paw No. 9 directly on switch S1, (+), from it C8 R6, then from it a resistor for 33k VD1 all this to switch S2, (-), and from paw 10 a diode to the same S2. And replace the diodes with kd521. The anode of one through a 33k resistor on the 9th paw, its cathode on the "-" switch. The second one is an anode for 10 paws, a cathode for the cathode of the first one. 9 paw is obtained directly on the "+" switch.

Author: Zero998, Associate Professor; Publication: radiokot.ru

See other articles Section Tone, volume controls.

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 Eye protection when working at a computer 02.04.2013 Visual impairment due to constant work at the computer is one of the biggest problems of our time, but it may soon disappear. American scientists have found a way to simply but effectively reduce eye fatigue. Researchers at the University of Texas came up with a simple strategy called "20-20-20-20". The bottom line is that a person working at a computer needs to take a break every 20 minutes and examine objects located at a distance of 20 feet from him (about 20 m) for 6 minutes. In this case, it is necessary to blink about 20 times. The effectiveness of such exercises is explained very simply. Blinking is a natural way to keep the surface of the eye moist. Doctors advise doing such exercises not only for regular computer users, but also for all those who want to preserve their vision for a long time. The new exercise helps prevent dry and tired eyes, headaches, neck and joint pain. Usually, neck discomfort and headaches due to overexertion are intermittent, but for many people it becomes a daily problem, leading to the daily use of painkillers and the need to see doctors. Those who spend three or more hours a day at the computer are at maximum risk. The 20-20-20-20 strategy may seem rather strange at first glance, but American scientists are confident that their technique works. It is noted that these exercises are especially important for office workers, developers, CAD engineers, programmers, etc., who spend most of their time at computers in rooms with dry and cold air from the air conditioner.

Other interesting news:

▪ Growing wood without a tree

▪ Canyon Wasabi smart watch

▪ The timing and quality of sleep varies by gender.

▪ Cotton as a semiconductor

▪ Convertible necklace headset from Samsung

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ website section LEDs. Article selection

▪ article by Titus Lucretius Car. Famous aphorisms

▪ article How does a seismograph measure earthquakes? Detailed answer

▪ article Industrial ventilation and air conditioning repairman. Standard instruction on labor protection

▪ article Tuning the computer system unit. Encyclopedia of radio electronics and electrical engineering

▪ article The disappearance of a glass of water. Focus Secret

Leave your comment on this article:

All languages ​​of this page

Arabic	Hebrew	Polish
Bengali	Hindi	Portuguese
Chinese	Italian	Spanish
English	Japanese	Turkish
French	Korean	Ukrainian
German	Malay	Vietnamese

Home page | Library | Articles | Website map | Site Reviews

www.diagram.com.ua
2000-2024