KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Author: search.filters.author.Wardkein, P.Subject: search.filters.subject.Pulse width modulation

Search Results

Now showing 1 - 2 of 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Pulse position modulation based on phase locked loop
    (2009-10-22)
    Wisartpong, P.
    ;
    Koseeyaporn, J.
    ;
    Wardkein, P.
    It is well know that Pulse Position Modulation (PPM) play an important role in optical and wireless communication, because of they save the power for transmission and obtained the high utilization of bandwidth. Consequently, in this paper PPM based on phase locked loop (PLL) with carrier and without carrier are proposed. It can easily adjust carrier frequency by tuning reference signal frequency of PLL. The proposed circuit is compose of voltage control oscillator (VCO), RC low pass loop filter, two mono stable multi vibrator and RS F/F. In order to obtain the PPM with carrier, we only add both output mono stable multi vibrator together. The experimental result show that this proposed PPM circuit work well and it is a compact size, when we compare with various signals that it can generate, such as Pulse Width Modulation (PWM), PPM, with and without carrier. ©2009 IEEE.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Item,
    Low-voltage high-speed PWM signal generations based on relaxation oscillator
    (2002-01-01)
    Siripruchyanun, M.
    ;
    Wardkein, P.
    This paper new two simple PWM (pulse width modulation) signal generations based on a modified relaxation oscillator are introduced. The advantages of the proposed principle are that the precise PWM signal can be easily achieved with a high frequency range up to several megahertz and a low-voltage power supply. The proposed circuits are able to accept either voltage or current modulating signals. They are very suitable for developing into integrated circuit (IC) form in communication applications. The simulation and experimental results are also depicted, and show good agreement with theoretical predictions.