in this paper, the results of design and implementation of the subsystems for generating loran pulse are proposed based on method of carrier’s pulse width change. in order to generate the desired pulse, firstly a pwm signal generated and then it is applied to a class-d switching amplifier. the results show that by generating appropriate pulses in digital fpga subsystem for application in switch...

this paper presents a novel control method to improve the efficiency of low-voltage dc-dc converters at light loads. pulse width modulation (pwm) converters have poor efficiencies at light loads, while pulse frequency modulation (pfm) control is more efficient for the same cases. switching losses constitute a major portion of the total power loss at light loads. to decrease the switching losses...

This paper presents a novel control method to improve the efficiency of low-voltage DC-DC converters at light loads. Pulse Width Modulation (PWM) converters have poor efficiencies at light loads, while pulse frequency modulation (PFM) control is more efficient for the same cases. Switching losses constitute a major portion of the total power loss at light loads. To decrease the switching losses...

Soft Switcing techniques have recently been applied in the design of dc-ac converters, in order to achive better performance, higher efficiency, and power density. One of the soft switching techniques uesd in inverters is resonant dc links. These topologies have some disadvantages such as irregular current peaks, large voltage peaks, uncotrollble pulse width, etc. Another soft switching method ...

Soft Switcing techniques have recently been applied in the design of dc-ac converters, in order to achive better performance, higher efficiency, and power density. One of the soft switching techniques uesd in inverters is resonant dc links. These topologies have some disadvantages such as irregular current peaks, large voltage peaks, uncotrollble pulse width, etc. Another soft switching method ...

in this paper, we investigate the parameters affecting total harmonic distortion (thd) and power supply rejection ratio (psrr) in pwm class d amplifiers (cdas) on the basis of linear models with feedback. from our mathematical analysis, we show that the thd of a pwm class d amplifier with feedback can be improved by increasing the gain of the integrator through adding another amplifier at the o...

This paper proposes a single-phase five-level inverter with a modified pulse width-modulated (PWM)control scheme. The modified pulse width-modulation technique is developed to reduce switching loss.Also, the proposed multilevel inverter can reduce the requirement of power switches compared to aconventional cascaded multilevel inverter. The modes of operation, control signals, and operatingprinc...

One of the best vibration control methods using smart actuators are semi-active approaches which are as strong as active methods and need no external energy supply such as passive ones. Compared with piezoelectric-based, magnetostrictive-based control methods have higher coupling efficiency, higher Curie temperature, higher flexibility to be integrated with curved structures and no depolarizati...

This paper describes the passive Qswitch, based on polymer and organic dye BDN, of a pulsed Nd:YAG laser. Pulses of 27ns duration and peak power of 1.7MW for initial transmission of Q-switch 18.4% 0 T = have been obtained. We have obtained Q-switching efficiency of 77% for train of pulses of 31 and 76.2% 0 T = at the pump energy of 98J. We have also obtained the dependency of laser pulse charac...

This Paper Presents a comparative study of Constant Switching frequency Multicarrier Pulse width Modulation and Variable Switching frequency Multicarrier Pulse width Modulation. The emergence of Multilevel converter has been in increase since the last decade . These new type of converters are suitable in high voltage & high power application due to their ability to synthesize waveforms with bet...