“Ah, summer red, I would love you, if not for the heat, and dust, Yes mosquitoes, Yes flies”. And although the high poetry of the great poet little combined with the dry prosaic lines, technical articles, these words can be safely put as the epigraph to this material. To stop the change of seasons in nature is impossible, and every year we have a “happening” summer, and with it come the usual worries of relief and localization of negative emotions, invariably manifested in humans with the appearance of annoying flying insects — mosquitoes, flies and other midges. To protect yourself from them, in nature and even at home someone buys a mosquito net, others treat themselves and family members with special insect repelling creams and formulations. However, possessing the skills, you can build a simple circuit protection device against mosquitoes, operating by using of ultrasonic radiation. What is ultrasound?A RESTFUL SLEEP IS GUARANTEED
“Ah, summer red, I would love you, if not for the heat, and dust, Yes mosquitoes, Yes flies”. And although the high poetry of the great poet little combined with the dry prosaic lines, technical articles, these words can be safely put as the epigraph to this material. To stop the change of seasons in nature is impossible, and every year we have a “happening” summer, and with it come the usual worries of relief and localization of negative emotions, invariably manifested in humans with the appearance of annoying flying insects — mosquitoes, flies and other midges. To protect yourself from them, in nature and even at home someone buys a mosquito net, others treat themselves and family members with special insect repelling creams and formulations. However, possessing the skills, you can build a simple circuit protection device against mosquitoes, operating by using of ultrasonic radiation. What is ultrasound?
Nine Eagles Galaxy Visitor 2 – a miniature copy of the legendary DJI Phantom quadrocopter, has no analogues in its class. The best engineers of the famous company proudly presented model, at small sizes has a number of features previously available only for the serious techniques of the professional level. The Galaxy Visitor 2 has functions such as hold the direction of flight, regardless of the spatial position and automatic return. Because of this quadcopter is not only simple and affordable for beginners – every pilot will appreciate the ability to save models with a complete loss of spatial orientation. Now at a great distance, You can easily capture footage! You like a spectacular night flights? An elaborate illuminated housing ensures excellent readability in the dark.
The proposed device is designed for “soft” on various radio and electrical household AC voltage of 220 V it is Known that the moment of switching devices containing a primary or secondary power circuits the capacitors of large capacity (high power audio amplifiers, switching power supplies and other devices), accompanied by a cast of current, which can reach tens of amperes.
In Amateur practice it is often required to provide an audible alarm, activated when the lighting of any object, the device responds to sudden illumination luminous flux working (photosensitive) surface of the photoresistor.
Probably you are familiar with simple electrical device for training “the steadiness of the hand” — a metal panel with a narrow winding slot, along which, without touching its edges, it is necessary to hold the pivot-pin. One careless touch probe to the edge and flashes the warning light. Such devices form the basis of the various attractions and special equipment. This principle is valid for our slot machine.
Electromechanical meters (hereinafter — meters) are used in industry to control the state (account) and hold the value of any device. Whenever the effects of a constant voltage to the coil (inside the housing of the Electromechanical counter) is changing its digital readings on one. This is achieved by using a winding with the armature, which, in turn, acts on the lever spring retainer, holding the counter wheels bearing digits. The control winding is a direct current. With each exposure to the appropriate stress occurs only one pulling and one releasing of the armature coil of the counter.
Designed and made by me lighting device externally, and by construction, some nodes resembles the flashing beacons of special machines. But the purpose of it almost the opposite — creating a smooth bright light, and at low power lamps — at a considerable distance. Well, since the scope of the devices are different and their structures are substantial, but rather fundamental differences.
Did you know that at the time shortwave Amateur radio communication, uniting hundreds of thousands of people in almost all countries of the globe, was to some extent the prototype of the Internet and current provider? In particular, short wave periodically going kind of forums (then they were called “round tables”), which discussed mainly technical issues related to the design of short-wave equipment and the passage of radio waves. On short waves to new friends and keep in touch with old And just this would need a homemade radio transmitter power from 10 to 40 watts and the HF-receiver. A thin “thread” of human relationships extends directly from one user to another without any intermediaries or service providers, without fiber and satellite communication and mobile phone companies.
Electric circuit “call” usually with a tester or device with audible indication. The probe, about which we talk today, informs about the health of an electric circuit with a light signal. He exhibited at the 29th all-Union exhibition of creativity of radio fans-designers. With such a device it is easy to find broken or short-circuited sections in strings and cables, checked relays, resistors, capacitors, fuses, light bulbs, determine the status of the p-n junctions for diodes and transistors. An indicator is a miniature light bulb, for example, CMH10-50.
If the stock is illiquid. burden burden of low-power portable radio (or a set of two stations), designed for communication in civil band 26,9 — 27,2 MHz, offer the option of their useful lives. Often, ham radio is both a car owner and cottager, who, as a person concerned for the safety of your car or suburban house. Besides there are many other areas of application of the proposed security devices on the basis of two portable radios. The main difference from other security systems is that the “alarm” signal is passed through the radio channel and range of action of the protection system depends on the power of radio transmitters and features of the passage of radio waves in the area of application of the system Even if there is only one radio station (CBS stations), is also not a problem as the receiver can use an all-band multimode transceiver type Kenwood FH-7E, Yaesu or similar (more about that below) in the circumstances, the transceiver is programmed to receive the appropriate frequency 27,175 MHz. Automatic shutdown function in the transceiver neutralized.