Preliminary study on pulse width adjustable pulse generator based on the magnetic switch and metal-oxide varistor

Adjustable Speed Drive Control Based on Random Pulse Width Modulation

The Pulse Width Modulation (PWM) power electronics systems often produce objectionable acoustic noise at the PWM switching frequency. For example, in a fan / blower drive, the drive used for the blower should use “spread spectrum PWM” technology (also known as Random PWM) where acoustic noise radiating through the duckwork is a very seriously concerned. This paper shows the theoretical basis fo...

Preliminary Design of Spacecraft Attitude Control with Pulse-Width Pulse-Frequency Modulator for Rest-to-Rest Maneuvers

In this paper, the preferred region of design parameters for quasi-normalized equations of single-axis attitude control of rigid spacecraft using pulse-width pulse-frequency modulator (PWPFM) is presented for rest-to-rest maneuvers. Using the quasi-normalized equations for attitude control reduces the system parameters, that is, the moment of inertia, the filter gain, and the maximum torque of ...

Design of Monophasic Spike-Exponential Waveform for Functional Electrical Stimulator Based on Pulse Width Modulation

The Functional Electrical Stimulator design using monophasic spike-exponential waveform was proposed and described in this study. The monophasic square waveform has benefit in generating an action potential, but it could cause side effects such as toxic caused by the electrode polarization. The square waveform signal which the frequency and pulse width could be modulated was manipulated to be t...

Metal Oxide ZnO-Based Varistor Ceramics

Picosecond Laser Source with Single Knob Adjustable Pulse Width

We describe and demonstrate a system which can be used with many types of actively modelocked lasers to create a source of variable width picosecond pulses. This system is an active compression scheme which incorporates a resonant electro-optic quadratic phase modulator to impart the linear frequency chirp on an optical pulse. To demonstrate, we used the modulator to chirp the 85 ps pulses from...