The energizing of large power transformers has long been considered a critical event in the operation of an electric power system. When a transformer is energized by the utility, a typical inrush current could be as high as ten times its rated current. This could cause many problems from mechanical stress on transformer windings to harmonics injection, and system protection malfunction. There h...

Transformers are normally designed and built for use at rated frequency and sinusoidal load current. A non-linear load on a transformer leads to harmonic power losses which cause increased operational costs and additional heating in transformer parts. It leads to higher losses, early fatigue of insulation, premature failure and reduction of the useful life of the transformer. To prevent these p...

Low-power dichroic halogen lamps, usually used for display lighting, have low-voltage filament. The lightweight electronic transformer (ET), based on self-oscillating half-bridge high frequency inverter, are used to replace bulky and heavy conventional 50160 Hz step-down transformer. But their lamp current are rectangular like shape, leading to generate high electromagnetic noise and increase t...

The DC/AC inverters are used in grid-coupled Photovoltaic (PV) energy fabrication systems as the power meting out interface between the PV power source and the electric grid. Compared to the grid-coupled PV inverters that have galvanic separation (either on the DC, or on the AC side),the transformer-less PV inverters have the advantages of lower cost, higher efficiency, smaller size and lower w...

A new synchronous rectifier (SR) driving method is proposed using primary current sensing in this paper. Because the magnetizing current of transformer is included in primary winding of transformer, it can’t be used to generate the driving signals of SRs directly. A current compensating winding in current transformer is used to cancel out the magnetizing current and generate suitable driving si...

Ultrasound methods are currently employed in a wide range of applications. They integrated complex electronics systems, like clinical echographs, but also small and compact boards, industrial sensors, embedded portable devices. waves typically generated by energizing piezoelectric transducer through high-voltage sequence sinusoidal bursts. Moreover, several applications, the ultrasound board sh...

Toroidal transformers are used to measure the beam current in beam lines and accelerators. Placing such a transformer hi the feedback loop of an operational amplifier will increase the useful frequency range (active current transformer). A magnetic modulator can be added to extend the response to DC current, maintaining with a control loop the transformer core at a zero flux state. The magnetic...