Pulse Width Modulation(PWM)

Discussion in 'The Projects Forum' started by micro, Apr 30, 2006.

  1. micro

    Thread Starter Member

    Feb 10, 2006
    Thanks, I have read the article called Pulse Width Modulation written by
    By Michael Adler and Tim Surtell at http://www.eleinmec.com/article.asp?28. May I know the mean of "The motor will work perfectly well, provided that the frequency of the pulsed signal is set correctly, a suitable frequency being 30Hz."? How do I set the frequecy to be 30Hz and how do I know my frequency is at 30Hz after setting? Thanks for your kind help. :D
  2. Papabravo


    Feb 24, 2006
    I did not find the phrase you quoted in the article, but the frequency is adjusted with the 470 K Ohm variable reisitor connected to pin 7 of the first 555 timer chip. You can look at the 555 output on pin 3, with an oscilliscope or a frequency counter. I think if the frequency is anywhere close to 30 Hz. say 20-40Hz you will be just fine.