Among elastic oscillations of air, ultrasound (from Latin ultra — beyond, more, above), inaudible to the human ear and with a lower frequency limit conventionally taken as 20 kHz, has long attracted special interest. Insects, bats, and even cetaceans make successful use of this natural gift: some for communication, others for hunting, others for locating Read more…
I made this soil-working tool to lighten the hard work, since digging the ground with an ordinary shovel—constantly bending and straightening—had become harder and harder over the years. The device itself is a modest invention (an author’s certificate was obtained for it), but it is useful: now my back does not hurt even after long Read more…
“The school automatic weather station, constructed by students of secondary school No. 5 in the city of Klin, is of technical interest. The precipitation sensor and its registration on the control panel are originally conceived and implemented. The wind direction and speed indicators, as well as the thermometer, are interesting. Such weather stations can also Read more…
Biogas. Used as far back as ancient China and then “rediscovered” millennia later as a “non-conventional, environmentally clean energy source of the 21st century,” it is attracting growing attention in our country too. Evidence of this is, in particular, the steady rise in publications related to biogas—including in the pages of Modelist-Konstruktor (see, for example, Read more…
It would seem that a shovel is such a simple tool that changing or improving its design is hardly possible. A handle and a blade—that’s the whole device. Nevertheless, there are many variations of this rather ancient farming (and not only!) implement. And the search for its modernization continues. Including by our readers, as evidenced Read more…
A jigsaw is a common tool. However, when working with it, one often runs into certain difficulties: the blade breaks, slips out of the clamps, and when cutting along a curved contour it often twists, which makes it hard to keep the desired direction. It is much more convenient to use an electrothermal (hot-wire) jigsaw, Read more…
Among self-defense devices, electroshock units (ESU) are far from the least notable, especially in terms of psychological impact on attackers. They are, however, quite costly, which motivates radio amateurs to build homemade analogues (see, for example, the detailed article on this in issue No. 5’99 of “Modelist-Konstruktor” magazine). Without claiming to be highly original or Read more…
The grass collector is designed to gather mowed stems; it has a cage welded from metal rods onto which the cut plants fall. There is also a control mechanism for the collector: a chain drive, a gear reducer, and a pair of rods bent at a right angle that act like a crank. Deflecting the Read more…
Motion sensor DD-010 disassembled with the control board removed and an additional siren (100 dB sound level) type KPS-4510 connected. Motion sensors (DD) based on Fresnel lenses and pyroelectric detectors can be used not only for their intended purpose – to turn on lights or as an element of a security alarm installed indoors. Cars Read more…
Perhaps this mechanism is the lightest in its family of counterparts: even a schoolchild can lift and carry it if need be. Low weight and utmost simplicity of construction—these are the qualities of the bicycle plow that drew the attention of visitors to the exhibition of young technicians’ work, participants in the All-Union rally of Read more…
