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...

The Raman-induced spectral shift of ultrashort pulses, having its origin in the phenomenon of intrapulse Raman scattering occurring inside silica fibers, has been mostly studied in the context of optical solitons. We use the moment method to show that such a spectral shift occurs both in the normal and anomalous-dispersion regimes and depends not only on the pulse width but also on the frequenc...

Metamaterials are an active area of interest currently due to their exotic electromagnetic properties not readily found in nature. In this report, the transmission line approach is used to design a Complementary Right Left Handed (CRLH) Transmisssion line. The characteristics of a modulated pulse propagation are studied. We look at how the variation of pulse width, centre frequency and pulse re...

A duty cycle control circuit for clock signals is presented. The proposed circuit uses a rising edge detector to generate one shot output signals which have the same frequency of the input clock signal. A pulse width controllable monostable multivibrator converts the one shot signals into rectangular pulses. By the feedback control voltage from an operational amplifier, the pulse width of gener...

introduction: effect of tripolar tens of vertebral column on slow and fast motoneurons (mns) activity of soleus muscle was previously investigated. in this study for better differentiation of the behavior of slow and fast mns, we exploited h-reflex recovery curve recording in two muscles of soleus and lateral gastrocnemius, respectively as the representatives of slow and fast muscles. methods: ...

In this paper, we present an ultra-wideband (UWB) pulse generator based on the step recovery diode. The principle of operation and the architecture of the developed pulse generator are explained. Furthermore, hardware implementation issues and the details on the generated UWB pulse including its peak voltage equal to 8.9 V, its full width at half maximum (fwhm) equal to 240 ps, and frequency sp...

We developed a new pseudo-attraction force display using four vibrating motors. The advantage of this device is that it uses phase difference control to alter the time width of pulses to generate asymmetric oscillation. It does not require altering the frequency of the vibrating motors. In this study, we investigated the influence of the pulse width generated in the device using vibrating motor...

One of the parameters of the pulsed RADAR that contributes range capability is the average power of the transmitter. The average power can be increased by increasing the peak power or transmitted pulse width or both. The complexity in the design of transmitter components to withstand high peak power is the most challenging task. On the other hand larger transmitted pulse width affects the RADAR...