The aspects regarding control strategies for Power Factor Correction (PFC) converters are investigated. The major control techniques to absorb sinusoidal input currents in boost PFC's are reviewed and analyzed. Their extension to other converter topologies is discussed and some experimental results for a PFC based on the Sepic topology are reported, which… (More)
— This paper presents the practical implementation of a fully digital control for boost power factor preregulators (PFP's). The control algorithm, which is simple and fast, provides a significant improvement in the system's dynamic performance compared to usual analog control techniques. The paper discusses the design criteria and the actions taken for the… (More)
Switch-mode power supplies represent a particular class of variable structure systems (VSS). Thus, they can take advantage of non-linear control techniques developed for this class of systems. In this paper the so called sliding mode control is reviewed and its application to switch-mode power supplies is discussed. Sliding mode control extends the… (More)
Protons and helium nuclei are the most abundant components of the cosmic radiation. Precise measurements of their fluxes are needed to understand the acceleration and subsequent propagation of cosmic rays in our Galaxy. We report precision measurements of the proton and helium spectra in the rigidity range 1 gigavolt to 1.2 teravolts performed by the… (More)
The use of an active voltage clamp in insulated DC/DC converters allows a limitation of the voltage stress due to transformer leakage inductance, a reduction of the commutation losses, and an increase of the switching frequency. It is therefore important to ensure soft switching in the whole operating range, penalty a considerable worsening of converter… (More)
Cosmic rays are the highest-energy particles found in nature. Measurements of the mass composition of cosmic rays with energies of 10(17)-10(18) electronvolts are essential to understanding whether they have galactic or extragalactic sources. It has also been proposed that the astrophysical neutrino signal comes from accelerators capable of producing cosmic… (More)
We present measurements of radio emission from cosmic ray air showers that took place during thunderstorms. The intensity and polarization patterns of these air showers are radically different from those measured during fair-weather conditions. With the use of a simple two-layer model for the atmospheric electric field, these patterns can be well reproduced… (More)
We review a series of 1,280 operated cases of carpal tunnel syndrome (CTS), with an unexpected high frequency of transverse muscular fibers within the carpal canal (11%), particularly in a group of young male patients under 30 years of age. This abnormal presence of muscle fibers could explain the early development of CTS in young male workers.