Browsing by Author "Kolář Milan"
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- ItemContinuous research report - project Drives No. 1/2015(2015-01-01) Kolář Milan
- ItemContinuous research report - project Drives No. 3/2015(2015-01-01) Kolář Milan
- ItemContinuous research report 2015_1 reliability TSR, ground fault analysis and possibilities of archivation on OS Linux(2015-01-01) Bedrník Tomáš; Kolář Milan; Kukačka Leoš; Černík Martin
- ItemContinuous research report 2015_2 Development, research and verification parameters of samples from platform F7 and F4.(2015-01-01) Bedrník Tomáš; Kolář Milan
- ItemExperimental Investigations and Modelling of a Composite Piezoceramic Disc with Different Modes of Vibrations(2017-01-01) Sikorová Iveta; Nosek Jaroslav; Kolář MilanThis contribution deals with the experimental investigations and modelling of the mechanical vibrations of the piezoelectric disc-shaped resonator, attached to a mechanically clamped metal membrane, which creates the composite resonator structure, the so called ultrasound therapy transducer. This transducer vibrates with a certain acoustic intensity at the typical frequency of 1 MHz, and the ultrasound waves are propagated into biologic tissue. The piezoelectric element in the composite structure is made from PZT ceramics; the clamped titanium membrane is tuned to the frequency of the resonator. Since a precise adjustment of the frequency of the transducer (which is exposed to the acoustical milieu of the air and other substances) is required, it is necessary to know the frequency spectrum of the vibrating composite resonator. This is influenced by a number of parameters. Tuning this composite structure is not a simple step in the manufacturing process, because the machining of the membrane is irreversible. In this paper, the completed investigations of the approach to the analytical solution of coupled vibrations of the piezoelectric resonators are presented, including the frequency spectra of the PZT disc-shaped resonator with a defined ratio of the diameter/thickness. However, this approach fails in the case of the real ultrasound transducer resonant structure (i.e., the disc-shaped resonator attached to the mechanically clamped metal membrane). Therefore the behavior of the vibrating structure has to be solved by some FEM method. In the described case the standard IEEE impedance/admittance measurement method and FEM simulation were used. The results allow an assessment of the suitability of the composite piezoceramic resonator in the terms of resonant frequencies, and tuning of the metal membrane to the appropriate resonant frequency.
- ItemExtra Low Voltage DC Grid LED Lighting Systems: Photometric Flicker Analysis(TU of Liberec FMMIS - ITE, 2015-01-01) Kukačka Leoš; Zissis Georges; Kraus Jan; Dupuis Pascal; Kolář Milan
- ItemFinal report - project Drives 2015(2015-01-01) Herajn Pavel; Černohorský Josef; Kolář Milan
- ItemLED Drivers: the Role of the Rectifier on Flicker Immunity in ELV DC Environment(IEEE, 2018-01-01) Kukačka Leoš; Dupuis Pascal; Zissis Georges; Kolář Milan; Kraus Jan
- ItemOn correct evaluation techniques of brightness enhancement effect measurement data(SPIE-Intl Soc Optical Eng, 2017-01-01) Kukačka Leoš; Dupuis Pascal; Motomura Hideki; Rozkovec Jiří; Kolář Milan; Zissis Georges; Jinno Masafumi
- ItemRequirements for the design of the HW-FM controller and the tyrisor switch module to compensate reactive power(2018-01-01) Novák Miroslav; Kukačka Leoš; Bedrník Tomáš; Černík Martin; Kolář Milan; Kraus Jan; Sopr Milan; Bleha Milan
- ItemResearch report - OptiMod project 2016(2016-01-01) Kolář Milan
- ItemRetrofit LED Lamps - Photometric Flicker Analysis(IEEE Industry Application Society, 2015-01-01) Kukačka Leoš; Dupuis Pascal; Zissis Georges; Kolář Milan
- ItemReview of AC power theories under stationary and non-stationary, clean and distorted conditions(IET Generation, Transmission & Distribution, 2016-01-01) Kukačka Leoš; Kraus Jan; Kolář Milan; Zissis Georges; Dupuis Pascal
- ItemThree-Phase Power Network Load Balancer(2016-01-01) Svoboda Miroslav; Slavík Lubomír; Kolář Milan