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EN
At carrying out the experiments to determine the losses for heating of magnetic nanoparticles (MNP) and composites on their basis, which are commonly used in the cancer treatment, it is necessary to reduce the number of manually regulated processes, e.g.: frequency change and resonance adjustment, alternating magnetic field strength amplitude change, as well as the measurements. In present article structural diagram of device for such purposes with improved automation level is presented and circuit engineering solutions for main measurement and automation nodes are proposed. There is an attempt to perform a purely electronic control of current flowing through the heating solenoid coil to adjust the magnetic field strength applied to the MNP sample without using any additional power electronics components.
EN
The paper presents complete, software-hardware solution of real-time measurement of frequency and amplitude of energic voltage signal besed on DSP processor. the hardware contains DSP board with A/D converter and 8051-based daughterboard with LCD and small keyboard. The software consists algorithm approximating sampled data of the valtage signed by a sinus function. This algorithm uses modified steepest descent method for error function minimization. An innovative modification was developed in order to reduce direction oscillations in the steepest cescent method. The modification increases the speed of function minimization by factor between 4 and 22. Results such as speed and accuracy are far better than in counting method of frequency measurement. Speed of about one measurement per secont was achieved using a 40 MHz TMS320c32 DSP processor. The maximum relative error of frequency measurement amounted to 0,56% at 60 samples of measured signal and 0,18% at 100 data samples.
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