Original file (958 × 797 pixels, file size: 81 KB, MIME type: image/png)
Summary
English: Principle of the intersective pulse width modulation (PWM). Created with maxima.
Author Original: CyrilB Vector: Krishnavedala
Source Code sawtooth(t) := t - floor(t); freq : 0.05$ sinesignal(t) := (1/2)+(499/1000)*sin(2*%pi*freq*t); pwm(t) := if(sawtooth(t) >= sinesignal(t)) then 0 else 1; load(draw)$ n : 1e4;kill(crossing); crossing : (x:[0],
for i:0 while i<20*n do
if( pwm(i/n)#pwm((i+1)/n) ) /* detect edge */
then x:append(x,[(i/n)]),
setify(x));
length(crossing); /* copy the x-tics from here */ source : gr2d(
font="Times",nticks=50,
grid=true,ytics={0,1},yrange=[-.25,1.25],
user_preamble="set format x "";set xlabel "" 0,1;
set bmargin 0;set tmargin 0",
xtics= {0,0.592,0.999,1.762,1.999,2.893,2.999,3.973,
3.999,4.998,4.999,5.975,5.999,6.911,6.999,7.816,7.999, 8.698,9,9.567,10,10.432, 10.999,11.301,11.999,12.183,12.999,13.088,13.999,14.024, 14.999,15.001,15.999,16.026,16.999,17.106,17.999,18.237, 18.999,19.407,19.999},
xlabel="",ylabel="source signals", explicit(sawtooth(x),x,0,19), color=red,explicit(sinesignal(x),x,0,19)
)$ pwm_plot : gr2d(
font="Times",nticks=50,
grid=true,ytics={0,1},yrange=[-.25,1.25],
user_preamble="set format x "";set bmargin 2.25",
xtics= {0,0.592,0.999,1.762,1.999,2.893,2.999,3.973,
3.999,4.998,4.999,5.975,5.999,6.911,6.999,7.816,7.999, 8.698,9,9.567,10,10.432, 10.999,11.301,11.999,12.183,12.999,13.088,13.999,14.024, 14.999,15.001,15.999,16.026,16.999,17.106,17.999,18.237, 18.999,19.407,19.999},
xlabel="Time",ylabel="PWM signal", color=magenta,explicit(pwm(x),x,0,19)
)$ draw(terminal=svg,file_name="Pwm",
source,pwm_plot);
Licensing
   | This work is licensed under the Creative Commons Attribution-ShareAlike 2.5 License. |
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 13:55, 30 August 2023 | | 958 × 797 (81 KB) | Isidore (talk | contribs) | English: Principle of the intersective pulse width modulation (PWM). Created with maxima. Author Original: CyrilB Vector: Krishnavedala Source Code sawtooth(t) := t - floor(t); freq : 0.05$ sinesignal(t) := (1/2)+(499/1000)*sin(2*%pi*freq*t); pwm(t) := if(sawtooth(t) >= sinesignal(t)) then 0 else 1; load(draw)$ n : 1e4;kill(crossing); crossing : (x:[0], for i:0 while i<20*n do if( pwm(i/n)#pwm((i+1)/n) ) →detect edge: then x:append(x,[(i/n)]), setify(x)... |
You cannot overwrite this file.
File usage
The following page uses this file:
