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How to apply ac voltage

Posted 29 gen 2010, 08:45 GMT-5 Low-Frequency Electromagnetics, Structural Mechanics Version 4.2a 3 Replies

Indhuja T
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Hi all
I want to apply ac voltage(using piezoelectric excitation) to an accelerometer to perform transient analysis.
I have tried the SPICE circuit editor, but it supplies only dc voltage.
Is there any way to apply a periodic input to the device.

Indhuja
3 Replies Last Post 17 ago 2012, 15:57 GMT-4
David Smith
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Posted: 1 decade ago 14 feb 2010, 06:17 GMT-5
Hi Indhuja,

You can supply an AC voltage to your model simply by entering a function for AC.

I'm not sure how your model is setup, but if you have entered a DC voltage you can change the function to AC.

For example, Vac = V*sin(2*pi*f*t), where V = amplitude, f = frequency, t = time (variable).

I hope this helps.

David.
Hi Indhuja, You can supply an AC voltage to your model simply by entering a function for AC. I'm not sure how your model is setup, but if you have entered a DC voltage you can change the function to AC. For example, Vac = V*sin(2*pi*f*t), where V = amplitude, f = frequency, t = time (variable). I hope this helps. David.
Arjan de Wildt
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Posted: 1 decade ago 16 ago 2012, 06:56 GMT-4
Dear Ivar,

I have a question that is sort of related to the one in this thread. For a cantilever that I am modeling that is subject to a constant DC current causing Joule Heating, I would like to determine the transient behavior. This means I want to see how the current, and with that the temperature and stress in the material, developes over time under influence of this voltage.

When running the time dependent study however I got the message that the solver could not evaluate the ec.DY (electrical displacement field in Y direction) variable. Because my model is quite complex I made a new simple model to investigate this. So I just have a rectangle (2D) that is fixed (SM) and has a potential over it (20+40*sin(1000*2*pi*t)). I defined a domain point probe and have done a time-dependent study again, but also here the same errors keep poppin up.

Why does this not work, what is not defined such that the electrical displacement field cannot be evaluated?

Could really use your help in this.
Have attached my model.

Thanks in advance.
Regards, Arjan
Dear Ivar, I have a question that is sort of related to the one in this thread. For a cantilever that I am modeling that is subject to a constant DC current causing Joule Heating, I would like to determine the transient behavior. This means I want to see how the current, and with that the temperature and stress in the material, developes over time under influence of this voltage. When running the time dependent study however I got the message that the solver could not evaluate the ec.DY (electrical displacement field in Y direction) variable. Because my model is quite complex I made a new simple model to investigate this. So I just have a rectangle (2D) that is fixed (SM) and has a potential over it (20+40*sin(1000*2*pi*t)). I defined a domain point probe and have done a time-dependent study again, but also here the same errors keep poppin up. Why does this not work, what is not defined such that the electrical displacement field cannot be evaluated? Could really use your help in this. Have attached my model. Thanks in advance. Regards, Arjan
Arjan de Wildt
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Posted: 1 decade ago 17 ago 2012, 15:57 GMT-4
Would anyone have any idea how to solve this?

In addition: if a 5V potential is applied then I reckon that it takes a while for the current to flow fully and thus also for the material to heat up (in the case of joule heating). This is the kind of behavior I would like to simulate, apply DC and see transient responses. Anyone any ideas?

Thanks already.
Would anyone have any idea how to solve this? In addition: if a 5V potential is applied then I reckon that it takes a while for the current to flow fully and thus also for the material to heat up (in the case of joule heating). This is the kind of behavior I would like to simulate, apply DC and see transient responses. Anyone any ideas? Thanks already.

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