Sensors are completely different. They differ in principle of action, the logic of their work and the physical phenomena and quantities to which they are able to respond. Light sensors are not only used in automatic lighting control equipment, they are used in a huge number of devices, from power supplies to alarms and security systems.

A photodetector in a general sense is an electronic device that responds to a change in the light flux incident on its sensitive part. They may differ, both in structure and in principle of operation. Let's look at them. A photoresistor is a photographic device that changes the conductivity (resistance) depending on the amount of light incident on its surface. The more intense the illumination of a sensitive area, the less resistance. It consists of two metal electrodes, between which there is ...

The idea of ​​making a small computer has been in the minds of engineers for many years. One of the most popular types of microcomputers is a smartphone - a symbiosis of a computer with its operating system and functionality and a cell phone. The proliferation of smartphones based on processors with ARM architecture, both processor manufacturers to make miniature but powerful computing systems, and electronics designers to develop in the direction of single-board systems.

System-on-a-Chip (SoC) is the English name for this type of computer. The first Raspberry pi board was announced in 2011 and put into production in 2012. Typically, Raspberry boards come in different versions, differ in the type designation “Model A”, “Model B” and the like, the differences are in the periphery and power.Despite the weak technical characteristics, the community of electronics and computer enthusiasts warmly welcomed such a concept. ...

In repairing equipment and assembling circuits, you always need to be sure that all elements are in good working order, otherwise you will waste your time. Microcontrollers can also burn out, but how to check it if there are no external signs: cracks in the case, charred areas, burning smell, and so on? For this you need: a power supply with a stabilized voltage, a multimeter, an oscilloscope.

A full check of all the nodes of the microcontroller is difficult - the best way to replace it with a known good one, or with the existing one, upgrade another program code and check its execution. In this case, the program should include both checking all the pins (for example, turning on and off the LEDs after a specified period of time), as well as interrupt circuits and other things. The microcontroller is a complex device in it multifunctional nodes. Before proceeding with its diagnosis, you need to familiarize yourself with the technical documentation...

A universal power supply is an indispensable thing that must be present in the workshop of any radio amateur. Test the newly developed circuit, check the device that came to hand, charge the battery, urgently power up some medical device, in which the power supply unit suddenly failed or the batteries simply run out.

But you never know, it may require constant voltage. And it would be good if the value of this constant voltage could be regulated within certain limits, and even better - the presence of a current control unit in the power supply, so that when a certain current value is reached, the voltage would no longer increase, but would be kept at such a level that the in no case would the load current be exceeded.The described needs are fully able to satisfy the laboratory power supply, which is a universal ...

Greenhouses are constructions intended for growing natural vegetables in a shorter period of time than in open ground. The use of greenhouses is common both among private owners and in agriculture as a whole. Many factors necessary for the effective cultivation of vegetable crops require the use of modern automation, for example: automatic maintenance of optimal air temperature, automatic watering, automatic lighting, automatic soil heating.

When growing tomatoes and cucumbers, as the most common crops grown in greenhouses, it is desirable that the air temperature be from +18 to +25 ° C during the day and not lower than +16 ° C at night. Soil temperature is from +10 ° С and higher.Lowering the temperature is carried out using actuators that open the windows of the greenhouse for ventilation when the air temperature rises...

In 1973, an American chemist Paul Lauterbur published an article in Nature magazine titled “Creating an Image Using Induced Local Interaction; examples based on magnetic resonance. " Later, British physicist Peter Mansfield will offer a more advanced mathematical model for acquiring an image of an entire organism, and in 2003, researchers will receive the Nobel Prize for discovering the MRI method in medicine.

A significant contribution to the creation of modern magnetic resonance imaging will be made by the American scientist Raymond Damadyan, the father of the first commercial MRI apparatus and author of the work “Detecting a Tumor Using Nuclear Magnetic Resonance”, published in 1971. But in fairness, it is worth noting that long before Western researchers, in 1960, the Soviet scientist Vladislav Ivanov already outlined the principles of MRI in detail, nevertheless he received an author’s certificate ...

A backlit switch is a convenient and beautiful solution. It is needed in order not to look at night with your hand where the light turns on, randomly clapping on the wall. But with the transition to energy-saving, and then to LED lamps, many encountered the problem that the light is blinking or dimly lit with such a switch. The backlight also causes this effect. In this article, we will explain why the LED bulbs flash when the light is off.

The switches set the backlight of one of two possible types: a neon bulb (glow discharge indicator) or an LED. Light indication on a neon bulb, as well as on LEDs consumes low current (units of milliamps). The neon indicator lights up when the switch is in the “OFF” position, that is, when its contacts are open. When you press a key, closing its contacts, the lamp turns on and the display turns off. The logic of work is elementary ...

To diagnose malfunctions in electrical equipment or electrical installations, it is often necessary to measure currents. There are two options: use an ammeter or using current clamps. The first option can be done using a conventional multimeter, but it is bad in that you need to break the circuit, and this is not always possible and not always convenient for correct measurements. The second method, clamp meters, allows you to find out the current in the circuit without disconnecting it.

The principle of operation of current clamps is based on the phenomenon of electromagnetic induction. The conductor, in which the current is measured, is inserted into the magnet wire, on which the secondary winding is wound.The measured current in this case is called primary, and the current in the measuring coil (secondary winding) is called secondary. Moreover, its value is proportional to the primary current and can be calculated. Previously, clamp meters, for the most part, could only measure alternating current ...