This article discusses the modeling of a 4th order Butterworth bandpass filter, with the Sallen-Key topology, composed of 2 stages with a bandwidth from 31.5 Hz to 8.5 kHz, designed to work as part of a digital noise level meter . Modeling was carried out in a modern computer-aided design package Filter Design Tool from Texas Instruments. The simulation results are presented, a conclusion is made about the correspondence of the parameters of the simulated filter to the calculated ones. The filter has a satisfactory quality factor, amplitude deviation in the passband, is quite simple and economically acceptable from the point of view of its implementation.

Keywords: noise meter, bandpass filter, Butterworth filter, Sallen-Key topology, modeling, CAD

This article discusses the development of a digital weather station with the measurement of geomagnetic field parameters. The advantage of the developed device is the possibility of simultaneous stable and correct operation of several sensors (namely 15), measurement accuracy at long distances (up to 300 meters). Structural and functional diagrams of the device have been developed. The voltage regulator of the device is designed in the Micro-Cap circuit analysis program. Experimental studies of the finished device were carried out.

Keywords: digital weather station, geomagnetic field, magnetic sensor, Arduino

This article considers the development of an information-measuring system for determining the thermophysical parameters of electrical devices. The developed functional diagram of the device is presented. Experimental studies were carried out in the COMSOL program. As a result of an experimental study of the transfer of heat from one part of the electromagnet to another, namely from the magnetizing coil, through the core to the environment, it was concluded that the best location of the temperature sensors is in the upper part of the body of the electromagnet EM-34-5. The data obtained can be used to determine the thermophysical parameters, in solving problems of the theory of inverse problems of heat transfer and heat transfer.

Keywords: information-measuring system, electrical devices, thermophysical parameters, COMSOL