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Rectangular Pulse Train Creation

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Hello,

I am attempting to create a pulse train for my model. I am new to introducing pulses and would like an equation to place on my electrcial potential module to create the following:

Rectangular wave: a) On for 0.1 sec at a voltage (VD), on a 1 second duty cycle (so on for 10% of a cycle)
b) repeating 10 times

Where; VD is my voltage applied.

Thanks for any help you can provide; I know how to create a single rectangle pulse and set voltage paramaters etc.

Regards,
Mike

4 Replies Last Post 10.10.2016, 20:03 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 20.12.2012, 02:12 GMT-5
Hi

Check the Forum, it has been discussed several times ;) you can obtain such "pulses" by combining the step or rect with an analytical function, you have also the advance make periodic options tab to play with

--
Good luck
Ivar
Hi Check the Forum, it has been discussed several times ;) you can obtain such "pulses" by combining the step or rect with an analytical function, you have also the advance make periodic options tab to play with -- Good luck Ivar

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Posted: 8 years ago 09.10.2016, 12:01 GMT-4
Hi,

I went through the posts in www.comsol.com/community/forums/general/thread/2924
where pulse train has been discussed in good detail. Thank you.

However,

In using COMSOL Analytic function with mod(t, value)
where value is less than 0.05 I am getting a straight horizontal line as output.

My pulse width (On time) is in micro seconds and would like to get 100 microsecond pulse width for 200 ms period.

Is it not possible to use mod function in this case ?

PS: I am unable to find "reply" option in the previous discussion thread,

Thanks,
Hi, I went through the posts in https://www.comsol.com/community/forums/general/thread/2924 where pulse train has been discussed in good detail. Thank you. However, In using COMSOL Analytic function with mod(t, value) where value is less than 0.05 I am getting a straight horizontal line as output. My pulse width (On time) is in micro seconds and would like to get 100 microsecond pulse width for 200 ms period. Is it not possible to use mod function in this case ? PS: I am unable to find "reply" option in the previous discussion thread, Thanks,

Jeff Hiller COMSOL Employee

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Posted: 8 years ago 10.10.2016, 08:12 GMT-4
Hello AJ,
Using mod is not recommended. Instead, see my post in this thread:
www.comsol.com/community/forums/general/thread/103901/
Best regards,
Jeff
Hello AJ, Using mod is not recommended. Instead, see my post in this thread: https://www.comsol.com/community/forums/general/thread/103901/ Best regards, Jeff

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Posted: 8 years ago 10.10.2016, 20:03 GMT-4
Hello Jeff ,

I am unable to give a On time (pulse width) of 100 microseconds.

I see only options of angular frequency and smoothing can be changed.

How do I change the pulse width (on time) ?
I am using rect() . it does not accept microsecond range. It gives a straight line. for values less than 0.0055

with 100 microsecond pulse and getting 100 pulses for a seconds seems to be not working when I try to plot by Jeff's method.

Is it a graphical limitation ?

I can get only upto 13 pulses in a second. not more than that
Hello Jeff , I am unable to give a On time (pulse width) of 100 microseconds. I see only options of angular frequency and smoothing can be changed. How do I change the pulse width (on time) ? I am using rect() . it does not accept microsecond range. It gives a straight line. for values less than 0.0055 with 100 microsecond pulse and getting 100 pulses for a seconds seems to be not working when I try to plot by Jeff's method. Is it a graphical limitation ? I can get only upto 13 pulses in a second. not more than that

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