79. Electronic circuits for controlling external devices are...
Transistors are elementary semiconductor devices, which today are the main elements for building logic chips, memory, processor and other computer devices.
System buses- These are sets of conductors for transmitting data, addresses and control signals between computer devices.
Controllers – CORRECT ANSWER
80. An intermediate buffer with fast access, containing a copy of that information that is stored in memory with less fast access, but with the greatest probability can be requested from there, is called ...
External memory is a non-volatile memory designed for long-term storage of programs and data. External memory devices include hard disk drives, floppy disk drives, optical compact discs, magnetic tape drives, and flash drives. It is significantly slower than internal RAM and ultra-RAM cache memory.
cache memory – CORRECT ANSWER
81. The integrated programming system includes...
text editor -CORRECT ANSWER
calculator
link editor –CORRECT ANSWER
graphics editor
Solution:
The process of creating programs includes the following stages: composing the source code of the program in a programming language; translation stage necessary to create the object code of the program; creation of a boot module ready for execution. In the most general case, to create a program in the chosen programming language you need to have the following components: 1. Text editor
2. Compiler. The source text is translated into intermediate object code using a compiler program.
3. Link editor, which links object modules and machine code of standard functions, finding them in libraries, and generates a working application as an output - executable code.
82. If the cluster size on the hard disk is 512 bytes, and the file size is 864 bytes, then _______ cluster(s) will be allocated on the disk for it (that is, inaccessible to other files).
Solution:
Each hard drive consists of a stack of platters. On each side of each plate there are concentric rings called tracks. Each track is divided into pieces called sectors, with all tracks on the disk having the same number of sectors. A sector is the smallest physical unit of data storage on external media. The sector size is always a power of 2, and is almost always 512 bytes. Groups of sectors are conditionally combined into clusters. A cluster is the smallest unit of data addressing. 
When a file is written to disk, the file system allocates an appropriate number of clusters to store the file's data. For example, if each cluster is 512 bytes, and the size of the file being saved is 800 bytes, then two clusters will be allocated to store it.
Let's say your file is located in 10 clusters of 1024 KB in size, and in the last - tenth cluster it occupies only ten bytes. What happens to the remaining almost free kilobyte? Nothing. It simply disappears for the user.
83. Using a digital camera, an image with a resolution of 3456x2592 pixels and a color depth of 3 bytes/pixel was obtained. For viewing, a monitor is used with the resolution settings set to 1280x1024 and 16-bit color rendering. The information volume of the image when displayed on this monitor will decrease by _____ times (round the resulting value).
Solution:
To calculate, it is necessary to take into account the resolution and color depth of the image and the monitor, and we find the ratio: 
Here the color depth is reduced to a single value - bits, which is used for calculation. So, the image will have dots, and for one point it will be highlighted 
, then the image size is Similar for the monitor, but here, when displayed on the screen, 16 bits are allocated per point.
DIY motion sensor connection diagram
It happens that you need to install lighting in your dacha or in your home. will be triggered by movement or a person or someone else.
A motion sensor, which I ordered from Aliexpress, works well with this function. The link to which will be below. By connecting light through a motion sensor, when a person passes through his field of vision, the light turns on and stays on for 1 minute. and turns off again.
In this article I’ll tell you how to connect such a sensor if it doesn’t have 3 contacts, but 4 like this one.
DIY power supply from an energy-saving light bulb
When to get 12 Volts for LED strip, or for some other purpose, there is an option to make such a power supply with your own hands.
DIY fan speed controller
This regulator allows for smooth adjustment variable resistor fan speed.
The circuit of the floor fan speed controller turned out to be the simplest. To fit into the case from an old Nokia phone charger. The terminals from a regular electrical outlet also fit in there.
The installation is quite tight, but this was due to the size of the case..
DIY plant lighting
DIY plant lighting
There may be a problem with lack of lighting plants, flowers or seedlings, and there is a need for artificial light for them, and this is the kind of light we can provide on LEDs with your own hands.
DIY brightness control
DIY brightness control
It all started after I installed halogen lamps for lighting at home. When turned on, they often burned out. Sometimes even 1 light bulb a day. Therefore, I decided to make a smooth switching on of the lighting based on a brightness control with my own hands, and I am attaching a diagram of the brightness control.
DIY refrigerator thermostat
DIY refrigerator thermostat
It all started when I returned from work and opened the refrigerator to find it warm. Turning the thermostat control did not help - the cold did not appear. Therefore, I decided not to buy a new unit, which is also rare, but to make an electronic thermostat myself using the ATtiny85. The difference with the original thermostat is that the temperature sensor is on the shelf and not hidden in the wall. In addition, 2 LEDs have appeared - they signal that the unit is turned on or the temperature is above the upper threshold.
DIY soil moisture sensor
DIY soil moisture sensor
This device can be used for automatic watering in greenhouses, flower greenhouses, flower beds and indoor plants. Below is a diagram on which you can make a simple sensor (detector) of soil moisture (or dryness) with your own hands. When the soil dries out, voltage is applied with a current of up to 90 mA, which is quite enough, turn on the relay.
It is also suitable for automatically turning on drip irrigation to avoid excess moisture.
Fluorescent lamp power supply circuit
Power supply circuit for a fluorescent lamp.
Often when energy-saving lamps fail, it is the power supply circuit that burns out, and not the lamp itself. As is known, LDS with burnt filaments, it is necessary to supply the network with rectified current using a starterless starting device. In this case, the filaments of the lamp are bridged by a jumper and a high voltage is applied to it to turn on the lamp. There is an instantaneous cold ignition of the lamp, with a sharp increase in voltage across it, upon start-up without preheating the electrodes. In this article we will look at starting an LDS lamp with your own hands.
USB keyboard for tablet
USB keyboard for tablet
Somehow, suddenly, I took something and decided to buy a new keyboard for my PC. The desire for novelty is irresistible. Changed the background color from white to black, and the letter color from red-black to white. A week later, the desire for novelty naturally disappeared like water into sand (an old friend is better than two new ones) and the new thing was sent to the closet for storage - until better times. And now they came for her, she didn’t even imagine that it would happen so quickly. And therefore the name would be even better suited not which is, but how to connect a usb keyboard to a tablet.
DIY clock with IN-14 lamps
DIY clock with IN-14 lamps
I have long wanted to post an article on making DIY watches with IN-14 lamps, or as they say, a watch in the steam punk style.
I will try to present only the most important things step by step and focusing on key points. The clock indication is clearly visible both day and night, and they themselves look very nice, especially in a good wooden case. Anyway, let's get started.
Electronic devices Now you won’t surprise anyone. They are in every home. Therefore, it is not surprising that from an early age many people become interested in electronics. In this case, most often they try to build some more or less complex device, using design descriptions. But first attempts rarely give good results.
But electronics is not at all difficult. All electronic devices, even the largest ones, are always made up of simple elements. There are only a few types of them. They are only connected to each other according to different schemes. That is why they work one way one time and another time another way - depending on the intentions of the designer. But that's not all: large electronic devices are made up of many small basic circuits. Just like using wooden cubes: often even a huge, magnificent palace can be built from identical bricks.
Let's talk about the construction of computers, amplifiers, pulse counters, and much more, about what is built from the basic elements: resistors, transformers, capacitors, transistors and integrated circuits that form the basis of radio electronics. Today's highly developed electronics industry employs tens of thousands of people. Some grow high-purity semiconductor crystals. Others manufacture integrated circuits using high-precision equipment. Still others develop their topology. The fourth are occupied with computer software. There are plenty of classes for fifth graders, sixth graders, etc. But all of them together are erecting one majestic edifice of modern electronic technology, without which not a single branch of the national economy can do without it.
Any modern building, for example a residential building, is built from a limited set of blocks - panels, beams, floors. By arranging these blocks in various combinations, you can build a low, long building and a skyscraper, rising like a tower over the entire city. Even with a limited set of basic blocks, architects are given wide freedom for creativity. So in modern electronics, from a relatively small number of basic basic blocks - “bricks”: transistors, capacitors, resistors, etc., you can create countless numbers: radios, televisions, sound recording and playback devices, data transmission, computers and many, many other. What are these elements?
Resistor
- a structural element of an electrical circuit, the main functional purpose of which is to provide a known resistance to electric current in order to regulate current and voltage. The resistor has the following basic parameters:
Power dissipation- this is the division of resistors by maximum power, measured in Watts.
Tolerance– this is the error of the resistor resistance, indicated as a percentage.
Now you can find both microminiature SMD resistors and powerful ones in a ceramic case. There are non-flammable, explosive and others, it would take a very long time to list them, but their basic parameters are the same.
Varicap - a capacitor in the form of a semiconductor diode, the capacitance of which nonlinearly depends on the electrical voltage applied to it. This capacitance represents the barrier capacitance of the electron-hole junction and varies from units to hundreds of picofarads. Varicap parameters:
Maximum reverse DC voltage– this is the maximum voltage that can be supplied to the varicap. Measured in Volts.
Nominal capacity of varicap– this is the capacitance of the varicap at a fixed reverse voltage.
Overlap coefficient is the ratio of the maximum capacity to the minimum.
In addition to conventional varicaps, dual and triple varicaps with a common cathode are used. Most often they are used in radio receiving devices, where it is necessary to simultaneously tune the input circuit and the local oscillator using one potentiometer. But they also make assemblies of several varicaps in one housing.
Transistor
- semiconductor triode - a radio-electronic component made of semiconductor material, usually with three terminals, allowing input signals to control the output current in an electrical circuit. Typically used to amplify, generate and convert electrical signals.
Main parameters of the capacitor:
Rated voltage- this is the voltage value indicated on the capacitor at which it can operate under specified conditions during its service life while maintaining parameters within acceptable limits.
Tolerance– this is the deviation of the actual capacity from that indicated on the case, indicated as a percentage.
Everything is constructed from a very modest set of basic elements at the disposal of radio engineers. From the electronic doorbell playing a melody to the complex synthesizers of modern bands; from a phone charger to a personal computer that can play a game of chess with you. But in modern construction, not only bricks are used, but also all kinds of blocks.
So what are these “building blocks”? Integrated circuits. Some of them are shaped like a small plastic brick with two combs of leads. According to their functional purpose, integrated circuits are divided into two main groups: analog, or linear-pulse, and logical, or digital, microcircuits. Analog microcircuits are intended for amplification, generation and conversion of electrical oscillations of different frequencies, for example, for receivers, amplifiers, and logical ones for use in automation devices, in devices with digital timekeeping, in computers.
Integrated circuit
is a miniature electronic unit containing transistors, diodes, resistors and other active and passive elements in a common housing, the number of which can reach several tens of thousands. One microcircuit can replace an entire unit of a radio receiver, computer and electronic machine. The “mechanism” of a digital wristwatch, for example, is just one chip.
The main element of analog microcircuits are transistors. The difference in transistor manufacturing technology significantly affects the characteristics of microcircuits. Microcircuits based on field-effect transistors are the most economical in terms of current consumption.
What is inside the radio-electronic element? The raw material for them can be ordinary sand. Don't believe me? Sand is silica SiO2 . And silicon is the basis for the production of the vast majority of semiconductor electronics elements. Of course, other materials are also needed: plastic, ceramics, aluminum, silver and even gold. It is best to cut a silicon wafer carefully and accurately with a diamond saw.
All this led to the emergence of micromodules, circuits on thin films, molecular blocks - these are all different ways to reduce the size of electronic devices. Since modern technology is faced with complex tasks, the implementation of which requires thousands of hours of trouble-free operation from electronic devices. Only miniaturization can improve the quality and reliability of elements. The smaller the dimensions of electronic devices, the more monolithic their structure, the easier they withstand shock and vibration loads. Monoblocks are not afraid of high temperatures, and their reliability is simply amazing - they can work without failure for tens of thousands of hours!
Miniaturization also affects the radioelements of circuits, simplifying their production, reducing their size, increasing productivity and reliability, which has helped man create the entire technology architecture necessary for any branch of his activity.
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Full review of the powerful Chinese 12-220 1000 watt converter. Testing the inverter, disassembling and inspecting the printed circuit board with parts.Since you have decided to become a self-taught electrician, then probably after a short period of time you will want to make some useful electrical appliance for your home, car or cottage with your own hands. At the same time, homemade products can be useful not only in everyday life, but also made for sale, for example. In fact, the process of assembling simple devices at home is not difficult at all. You just need to be able to read diagrams and use the ham radio tool.
As for the first point, before you start making electronic homemade products with your own hands, you need to learn how to read electrical circuits. In this case, ours will be a good helper.
Among the tools for novice electricians, you will need a soldering iron, a set of screwdrivers, pliers and a multimeter. To assemble some popular electrical appliances, you may even need a welding machine, but this is a rare case. By the way, in this section of the site we even described the same welding machine.
Special attention should be paid to available materials, from which every novice electrician can make basic electronic homemade products with their own hands. Most often, old domestic parts are used in the manufacture of simple and useful electrical appliances: transformers, amplifiers, wires, etc. In most cases, novice radio amateurs and electricians just need to look for all the necessary tools in a garage or shed in the country.
When everything is ready - the tools have been collected, spare parts have been found and minimal knowledge has been obtained, you can proceed to assembling amateur electronic homemade products at home. This is where our small guide will help you. Each instruction provided includes not only a detailed description of each stage of creating electrical appliances, but is also accompanied by photo examples, diagrams, as well as video lessons that clearly show the entire manufacturing process. If you don’t understand some point, you can clarify it under the entry in the comments. Our specialists will try to advise you in a timely manner!
The author has developed a program and device for controlling various electrical and radio devices using a computer. The device is connected to one of the COM ports, and the devices can be controlled using both on-screen keys and external sensors.
The device diagram is shown in Fig.1. Its basis is the 74HC595 chip, which is an 8-bit shift register with serial input and serial and parallel information outputs. Parallel output is carried out through a buffer register with outputs that have three states. The information signal is supplied to the SER input (pin 14), the write signal to the SCK input (pin 11), and the output signal to the RSK input (pin 12). The DA1 chip contains a 5 V voltage regulator to power the DD1 register.
Figure 1. Device diagram
The device is connected to one of the COM ports of the computer. Information signals arrive at pin 7 of the XS1 socket, information recording signals go to pin 4, and information output signals go to pin 3. COM port signals, according to the RS-232 standard, have levels of about -12 V (log.1) and about +12 V (log.0). These levels are paired with the input levels of register DD1 using resistors R2, R3, R5 and zener diodes VD1-VD3 with a stabilization voltage of 5.1 V.
Control signals for external devices are generated at outputs Q0-Q7 of register DD1. The high level is equal to the supply voltage of the microcircuit (about 5 V), the low level is less than 0.4 V. These signals are static and are updated when a high level arrives at the RSK input (pin 12) of the DD1 register. LEDs HL1-HL8 are designed to monitor the operation of the device.
The device is controlled using the UmiCOM program developed by the author. The appearance of the main program window is shown in Fig.2.
Figure 2. Appearance of the UniCOM program
After starting it, you should select a free COM port and output switching speed. The state of each of the device outputs is entered into the table rows (high level - 1, low level - 0 or empty). The program “sorting” through the table columns in the operating cycle sets the corresponding logical levels at the device outputs. The information entered into the table is automatically saved when the program is terminated and loaded again the next time it is launched. For clarity, on the left side of the program window the numbers of outputs on which the high level is set are highlighted.
Devices can also be controlled using external contact sensors, which are connected to inputs 1-3 and the +5 V line. They must operate to close or open contacts. An example of a sensor connection diagram is shown in Fig.3.
Figure 3. Connecting contact sensors
When you press the "Input Setup" softkey, the "Input and Output Assignment" window opens ( Fig.4.), where inputs are selected that will change the state of the outputs. You can simulate the operation of the inputs by pressing the screen keys “1”, “2”, “3” of the main program window. In cases where devices cannot be controlled using logical levels, a relay should be used, the connection diagram of which is shown in Fig.5, or transistor optocoupler ( Fig.6.).
Figure 4. Input and output matching
Figure 5. Relay connection diagram
Figure 6. Transistor optocoupler connection diagram
Most of the parts are mounted on a printed circuit board made of single-sided foil fiberglass laminate with a thickness of 1...1.5 mm, the drawing of which is shown in Fig.7. Resistors R1-R6 are mounted on the terminals of socket XS1.
Figure 7. PCB drawing
The device uses resistors C2-23. MLT, oxide capacitors - K50-35 or imported, XS1 socket - DB9F. In addition to the zener diodes indicated in the diagram, you can use BZX55C5V1 or domestic KS174A, any LEDs. The device is powered from a stabilized or unstabilized power source with a voltage of 12 V and a current of up to 100 mA.
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