Music CD player. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Audio equipment
Comments on the article
The player provides the following service functions: automatic CD loading, normal playback mode, search for the previous or next fragments, accelerated search for fragments with a resolution of 10 s, playback mode for the beginning of each fragment ("REVIEW"), temporary playback stop ("PAUSE") , indication on the panel of the main modes of the PKD robots, electronic adjustment of the analog output signal ("VOLUME"), indication of the fragment number (up to 99 fragments), five modes of displaying time data (total playing time of the disc, playing time of the selected fragment, time until the end of the fragment, time to end of disc, total time to end of disc).
(click to enlarge)
The basis of the controller (see figure) is an AT8C89 51-bit microprocessor from ATMEL. The player's algorithm is implemented in software, which greatly simplifies the circuit itself. The controller itself is connected to the CD-ROM drive via a K555AP6 bidirectional bus driver with a 40-wire cable. Registers 03, 04 and 05 are responsible for the dynamic indication of the time counter and track number. The PKD is controlled by 10 switches with normally open contacts.
Indication of the basic operating modes of the PKD ("STOP", "START", "FAST-FAST-BACK") is made on four single LEDs. The track number and playing time indicator is digital, six-digit, where two digits indicate the track number (up to 99), and the rest indicate the playing time in minutes and seconds.
All elements of the circuit (except indicators) are placed on a double-sided printed circuit board measuring 75 x 75 mm. Connector X1 can not be installed, but the cable can be soldered directly to the board. The processor can be used any 51-compatible with a program memory of at least 2K. Single indicators can be of any type, digital with a common cathode, 9-digit, located on a separate board (used in caller IDs). You can also use single 7-segment indicators by connecting the pins of the same name together.
The printed circuit board is designed for the use of resistor matrices, but it is possible to use single resistors. They are soldered to the board with one output, and all together they are soldered "in the air" and connected to the positive power wire. A properly assembled circuit practically does not need to be adjusted. When you first turn it on, you need to check the current consumption (maximum 100 mA) and make sure that there is a generation of a quartz resonator The power supply of the VRM must provide at least 1A for 12V and 0,8A for 5V.
See other articles Section Audio equipment.
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 Magnetic nano-probes for cell research
29.03.2020
Most likely, in the near future, so-called nano-bots will be actively used in practical medicine - special nanoscopic micro-robots that can be used to deliver medicinal compounds bypassing all barriers, because such things are being developed and tested now. However, the application of the standard procedure for placing nano-bots in a living cell is rather complicated, primarily from an energy point of view. Therefore, a team of scientists from the University of Toronto presented their new method of such delivery and more precise movement, as well as direct control of a nano-bot inside a cell.
The use of a standard type of such a nano-bot involves the use of a sufficiently concentrated and energy-consuming laser beam, with which you can control the movement of the robot in a cage, but with known limitations and low accuracy. This can be corrected by increasing the concentration of the beam, but at the same time, the likelihood of seriously harming the cells increases.
That is why the Toronto experts have presented their new approach to such movement by increasing the degree of magnetism of their drug delivery nano-bots. The scientists created several units of these sub-700nm micro-bots and placed them in live cancer cells - and then moved the entire system onto special chemical pallets. By observing the movement of the bots inside the cages, the specialists were able to accurately and quickly control their movement using magnetic coils installed outside the cages. With this selection, they managed to significantly increase the accuracy and responsiveness of the movement of nano-bots, which made them more efficient.
A new drug delivery system of this type is becoming more efficient and interesting in absentia, including from the point of view of the resources spent. Despite some mistakes and unfinished moments, even now such a system demonstrates a really great potential for its subsequent application in practical medicine.
|
Other interesting news:
▪ Experiments with e-waste
▪ Microsoft is blocking the installation of Linux on its tablets
▪ An energy explosion has been recorded in the Earth's magnetosphere for the first time
▪ OneXGPU graphics card with built-in SSD storage
▪ Efficient artificial photosynthesis
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ section of the site Data transfer. Article selection
▪ article Panic fear. Popular expression
▪ article How many crocuses do you need to collect to get a kilogram of saffron? Detailed answer
▪ article Electric winch driver. Standard instruction on labor protection
▪ article Transformerless voltage converter. Encyclopedia of radio electronics and electrical engineering
▪ article A simple voltage regulator with short circuit protection, 15-38 volts 3 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