I offer readers of our favorite magazine an automatic plant watering and spraying system of my own design, which has proven itself both indoors and in a greenhouse, winter garden, and flower bed. It consists of two interconnected subsystems: “sensor — water supply” (fig. 1) and an electronic control unit (fig. 2). While the first Read more…
Smartphones look similar on the outside, but the real changes are inside. iPhone 17 teardown — a journey into Apple’s engineering kitchen. Engineers worked hard: fixed old problems, made bold moves. Teardowns help understand “how it’s made” — how long the device will last, how it will survive drops, how painful battery replacement will be. Read more…
A compact incubator in which you can hatch turkeys and chickens, ducks and geese, operates from an AC power supply. The design automatically maintains the required temperature: chicken and turkey eggs are cooled twice a day, and waterfowl eggs — four times. In addition, the machine turns the eggs 180° every hour. If something fails Read more…
This device helps detect hidden large metal objects at depths up to 0.6 m. It is needed by builders, gas service workers, and utility workers to search for metal manholes and covers that, during building construction or street reconstruction, ended up under a layer of earth, asphalt, or were covered by sand. With a metal Read more…
“Open Sesame” — with these words, the resourceful and brave Ali Baba opened the magic door to the cave with treasures. Let’s imagine that Ali Baba is solving a more difficult task — trying to open the door to another cave, the entrance to which is blocked by a magic barrel. It can rotate around Read more…
This device can quickly and accurately measure, for example, the temperature of a human body, water, and air. An electronic thermometer is needed by agricultural workers to determine the temperature of grain, potatoes, and soil, and by medical workers. The thermometer consists of five main units: a temperature-to-frequency converter, a rectangular pulse generator, a pulse Read more…
The automation device I designed is intended for farmers and owners of dachas with an autonomous water supply system whose key elements are a water source (river, lake, well or borehole), an electric pump and a pressure tank. Unlike similar devices, this one not only performs the main function—controlling the electric pump—but also handles security Read more…
When heating a fireplace or sauna stove at a dacha with wood, the combustion process must be monitored from time to time: adding firewood, increasing draft, etc. The proposed electronic device can replace the “owner’s eye” and remind of this by signalling when the flame in the stove (firebox) diminishes. I experimented a bit and Read more…
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…
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…
