Owl eyes. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Beginner radio amateur
Comments on the article
This toy (see figure) differs from similar "flashing lights" that control LEDs in that both LEDs flash at the same time, and then their brightness gradually decreases until completely extinguished, followed by a relatively long pause.
If the LEDs are fixed in place of the eyes of some soft children's toy, for example, an "owl", it will give the impression that it, as it were, reluctantly and briefly opens its eyes, after which it closes them smoothly, again falling into a dream.
The basis of the device is a digital microcircuit KR512PS10 built using CMOS technology. It is an RC oscillator and a controlled frequency divider with a switchable division factor [1]. In the proposed use of the microcircuit, one of its control inputs is switched on so that the division factor changes cyclically during operation [2]. When output pin 9 is logic high, it goes to input 26 (pin 1). The division factor of the microcircuit counters is 131072. If a low level appears on pin 9, the division factor drops to 2048.
The second output of the microcircuit (pin 10) is inverse, compared to the first. Since the counter division ratio is switched, the high level on it is shorter than the low level by 64 times (131072:2048 = 64). At a clock frequency of the microcircuit generator of 4900 Hz, the high level at the second output lasts 0,2 s, the low level lasts about 13,5 s.
A short high-level pulse charges the oxide capacitor C1 through diode VD3 and resistor R3. The composite transistor VT1VT2 opens, the LEDs HL1, HL2 light up. At the end of the pulse, the capacitor C3 begins to gradually discharge through the resistors R4, R5 and the emitter junctions of the composite transistor. The current through the junctions drops, the brightness of the LEDs gradually decreases and soon they go out.
The duration of the LEDs is about 2 s, and the pause between their flashes is about 12 s. Diode VD1 prevents the discharge of the capacitor C3 through the microcircuit and VD2 protects the microcircuit from the wrong polarity of the power supply connection.
Transistors - any of the KT342, KT3102, KT3130 series with a base current transfer coefficient of at least 150, VD1 diode - any low-power silicon, for example, KD103, KD521, KD522, VD2 series - indicated on the series diagram or KD202, KD209, KD212. LEDs - any yellow or green glow. Large LEDs look spectacular - with a diameter of 10 mm. Capacitors C1, C2 - any ceramic, C3 - K50-16, K50-35, resistors - MLT. The power supply can be made up of three or four cells 343 or similar connected in series.
With an average current consumed by the device of not more than 3,5 mA, such a source will last for several hundred hours of continuous operation.
A properly assembled device does not require adjustment. If you want to change the frequency of LED flashes, you can choose a resistor R1 with a resistance of 30 ... 150 kOhm.
Literature
- Biryukov S. Frequency divider generator KR512PS10. - Radio, 2000, No. 7, p. 51-53.
- Biryukov S. Application of the KR512PS10 chip. - Radio, 2000, No. 8, p. 44.
Author: Zh.Mikheeva
See other articles Section Beginner radio amateur.
Read and write useful comments on this article.
<< Back
Latest news of science and technology, new electronics:
Traffic noise delays the growth of chicks
06.05.2024
The sounds that surround us in modern cities are becoming increasingly piercing. However, few people think about how this noise affects the animal world, especially such delicate creatures as chicks that have not yet hatched from their eggs. Recent research is shedding light on this issue, indicating serious consequences for their development and survival. Scientists have found that exposure of zebra diamondback chicks to traffic noise can cause serious disruption to their development. Experiments have shown that noise pollution can significantly delay their hatching, and those chicks that do emerge face a number of health-promoting problems. The researchers also found that the negative effects of noise pollution extend into the adult birds. Reduced chances of reproduction and decreased fertility indicate the long-term effects that traffic noise has on wildlife. The study results highlight the need ... >>
Wireless speaker Samsung Music Frame HW-LS60D
06.05.2024
In the world of modern audio technology, manufacturers strive not only for impeccable sound quality, but also for combining functionality with aesthetics. One of the latest innovative steps in this direction is the new Samsung Music Frame HW-LS60D wireless speaker system, presented at the 2024 World of Samsung event. The Samsung HW-LS60D is more than just a speaker system, it's the art of frame-style sound. The combination of a 6-speaker system with Dolby Atmos support and a stylish photo frame design makes this product the perfect addition to any interior. The new Samsung Music Frame features advanced technologies including Adaptive Audio that delivers clear dialogue at any volume level, and automatic room optimization for rich audio reproduction. With support for Spotify, Tidal Hi-Fi and Bluetooth 5.2 connections, as well as smart assistant integration, this speaker is ready to satisfy your ... >>
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 ... >>
| Random news from the Archive Silver nanowire instead of ITO film
12.11.2013
Today, the Indium Tin Oxide (ITO) conductive film technology, which is used in the production of transparent electrodes for liquid crystal screens, OLEDs, touch displays, as ohmic contacts to solar cells, as well as in other optoelectronic devices, may lose its position more advanced alternative solutions capable of entering this market and pushing out the ITO technology that has been established there.
The priority direction for ITO technology is the use of films as a coating for touch panels of modern displays. According to IHS Inc.'s Touch-Panel-Use Transparent Conductive Film Report - 2013, electrically conductive ITO films, which combine indium(III) oxide and tin(IV) oxide, account for 95% of the market for transparent conductive coatings for touch screens. But there is a high probability that by the end of 2017, an alternative technology may enter this segment and displace ITO from the position of the undisputed undisputed leader.
Such an alternative can be the use of silver nanowire, copper and silver mesh, silver halide. These technological solutions are predicted to be able to capture about 2017% of the market by 34, leaving 2/3 for ITO. Such a prospect could hit ITO positions hard, because even now the supply of films without the content of indium oxide and tin oxide compounds in their composition is on the way to a large-scale jump, which, according to reports for this year, has already amounted to 320%. This indicator is a record of annual growth in the market of modern technologies according to IHS experts.
The ITO compound is applied in two components: film and glass. The specific surface resistance of the film is very large and equals 100 Ohm/m2, which means that the limit of using such material in touch panels is limited to a diagonal of 15". As for ITO-glass, its resistance is 2 times less than the resistance of the film - 50 Ohm/m2, therefore such glasses are used in panels with a diagonal of more than 15". Despite technological shortcomings, the use of ITO glass is possible up to 30" displays.
The main stumbling block in the development of ITO technology for touch displays, as the main component, is the sharply increasing demand for touch panels with large diagonals. "Here, ITO has serious functional weaknesses and limitations," said Irene Heo, principal analyst for display materials and components at IHS, in a presentation. The main purpose of touch panels until recently were devices that used small displays - smartphones, tablets, car navigation systems, ATM displays. But the need for the production of large-scale touch panels is becoming more relevant and necessary every year. The increased demand for devices such as electronic whiteboards and All-in-One personal computers is pushing the manufacturer to abandon ITO and stimulate the development of an alternative direction - the use of technology without indium tin oxide.
Coatings without the use of an ITO compound compete with both ITO films and ITO glasses of various sizes, and also fill a free niche for devices with a large display diagonal, where an ITO compound cannot be used in principle. It is this direction that provides today, first of all, the increased demand for alternative electrically conductive films.
It should not be forgotten that the production of ITO coatings is quite expensive and limited due to the rare indium metal, whose oxide makes up 90% of the mass fraction of the compound. Therefore, the use of films without these elements is not only a technically more advanced step, but also an opportunity to obtain a significant economic effect.
|
Other interesting news:
▪ The world's largest wave power plant will be built
▪ Sound can travel even in a vacuum
▪ Microcontroller Toshiba TMPM46BF10FG
▪ Laptops instead of seismographs
▪ Transcend TS128GMTS810 Solid State Drive
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ section of the site Civil radio communications. Article selection
▪ Article Investments. Lecture notes
▪ article What familiar object helps to see through opaque frosted glass? Detailed answer
▪ article Mechanized complex-tool. home workshop
▪ article Device for the selection of containers. Encyclopedia of radio electronics and electrical engineering
▪ article Power amplifier KB transceiver. 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