In the old days tresses are able to sharpen many, although it is not easy: before you bring the blade up to the ringing of the sharpness of the grindstone, it beat with a special hammer on a rounded anvil. Now, few people know the art of hitting. And it would be necessary. For example, in collective farm “Progress”, sponsored our Cuto, in the time of haymaking on the fringes of the forest and other uncomfortable for the Parking the grass mowed manually. KOs, of course, a lot, and the old man who knows how to discourage them, a few units do not have until the new dawn, the bot came to us farmers to help mechanize the process.THE FOCUS WITH THE FOCUS
If you have a SLR camera and adapter rings, make a photocopy knizhnoi articles, magazine pages, or other reproductions not accounting for labor. However, the camera “Zenit-GP” with lens “Industar-50” for it is not very convenient: it is not easy to find him adapter rings with thread M39. 1, and make them very difficult. But, Read more…
The world’s first experimental jet aircraft is Not. 178 flew in Germany on 27 August 1939, Quite apart from him in “Gloucester” (UK) was established aircraft E28/39 with a turbojet engine (TRD), which took to the skies in may 1941, the Third aircraft with a gas turbine engine, patented F. Willem, soared in the United States. It happened October 2, 1942 the First combat aircraft with turbojet was Me.262, created under the leadership of V. Messerschmitt.
For years, the rubber motor due to its ease of use and low cost were the main engine modelers. But now, with the abundance of micro-motors boat and car with rubber motor find its ardent supporters, as evidenced, in particular, and editorial mail. Among your questions, dear readers, the most frequent two. So T zavgorodnego from Volgograd, E. Shcherbina from Semipalatinsk, A. Zhdanov of Moscow and other interested in how to calculate the number of turns of the rubber motor to maximize its energy, and what is its maximum energy efficiency.
To build and repair electronic equipment needs generators low and high frequencies. A simple device, a scheme which offers the British magazine “Radio Electronics Constructor”, replace them at first. The single junction transistor V1 performs the functions of the relaxer. The value of resistor R1 and capacitor C1 determine the value of the audio frequency (about 1 kHz). It change the selection of capacitor C1. Using an isolating capacitor C3 of the low-frequency signal is supplied to the output socket. And since it has a sawtooth form, that contains a large number of higher harmonics.