square wave train

[payman]

Hello,

I want to create a square wave train with 40 kHz frequency. The problem with the attached worksheet is

1- it doesn't start from zero amplitude

2- I don't know how to add the factor (x-vt) , x= position and v=the sound speed, to simulate the wave train propagation in "x" direction.

Could you please give me some hints.

All the best

Payman

[Fred_Kohlhepp]

Maybe a place to start

[-MFra- · Accepted solution]

Example of voltage step propagation, along a line, in space and time:

[Fred_Kohlhepp]

Fixed to start at zero

[payman]

thank you, the worksheet generates an infinite train , how can I truncate it to 10 periods ?

[LucMeekes]

This should do it, for any frequency Fs, amplitude A, duty-cycle d and number of periods p:

Success!
Luc

[Fred_Kohlhepp]

Nicely done

[prop_design]

hi luc,

your solution to this looks interesting. i'd like to try it out, but i don't see a mathcad file for it. can you post it?

thanks,

anthony

[LucMeekes]

You should be able to type it in yourself.

But, OK, see attached.

Success!
Luc

[prop_design]

thanks luc,

i wasn't sure if there was more to it or not. i played around with the file you posted. it seems to have a lot of odd behavior depending on the inputs used. one odd thing is the duty cycle is at the end of the cycle rather than the beginning. the other odd things seem to be input limitations. kinda hard to explain.

[prop_design]

hi,

here is a modification that works more like what i was expecting. i'll make a new thread using it to drive a mass spring damper. thanks for this. i never would have figured it out without your post.

anthony