The simplest electrical devices that our magazine offered to beginners work from a 3336L battery for a pocket flashlight. But it cannot provide much energy: after several hours of continuous operation, the battery “runs down”, and then it needs to be replaced. It is much more convenient to power homemade devices from a constant source 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…
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…
A vehicle’s electrical system can be supplemented with a device whose schematic and wiring are within reach of even a beginner. This device is a controller whose value is clear: its status LEDs give constant, reliable information on the condition of the stop lamps, with minimal draw from the onboard supply. When the brake pedal Read more…
