voltage waveform across R and C for ramp input

[GBHT]

if i have a ramp input to a simple first order low pass RC circuit, then what will be the waveforms across R and C ? i am not able to get the ramp input in my simulation software(TINA-student version)..plz help.. thank you..

 

[crutschow]

It depends upon the frequency of the ramp, the RC time-constant, and how the R and C are connected. If you supply that information we can provide more info. ;-)

 

[ZekeR]

When applying a voltage ramp appearing across a series RC network, the voltage across the capacitor will settle to a ramp (with a smooth start), while the voltage across the resistor will settle to a constant voltage.

I prefer to use LTspice rather than TINA, because it is free and fully supported and has a much bigger user community — **broken link removed**.

 

[godfreyl]

i am not able to get the ramp input in my simulation software(TINA-student version)

The trick is to use a pulse (or squarewave) generator. If you set the rise and/or fall times long enough, you can get a triangle or sawtooth output.

Hopefully that will work in TINA. I use SIMetrix SIMPLIS. It's also free, good and easy to use. LTSpice, suggested by ZekeR, is also free and good, but imho much harder to use.

 

[GBHT]

It depends upon the frequency of the ramp, the RC time-constant, and how the R and C are connected. If you supply that information we can provide more info. ;-)

frequency of the ramp?? well the slope of the ramp is 1 and the circuit is 1st order low-pass circuit..1 resistor and 1 cap with a voltage supply.. and RC time constant ? i don't think we really need it here..

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The trick is to use a pulse (or squarewave) generator. If you set the rise and/or fall times long enough, you can get a triangle or sawtooth output.

Hopefully that will work in TINA. I use SIMetrix SIMPLIS. It's also free, good and easy to use. LTSpice, suggested by ZekeR, is also free and good, but imho much harder to use.

there is an option called user defined signal..but i am not able to use it in my circuit.. may be that option is not available for student version.. thank you

 

[crutschow]

frequency of the ramp?? well the slope of the ramp is 1 and the circuit is 1st order low-pass circuit..1 resistor and 1 cap with a voltage supply.. and RC time constant ? i don't think we really need it here..

A slope of 1 tells me nothing rate of rise of the slope. And if you can simulate a circuit without a specific value for the R and C, then you have a very unusual simulator. :-?

 

[GBHT]

A slope of 1 tells me nothing rate of rise of the slope. And if you can simulate a circuit without a specific value for the R and C, then you have a very unusual simulator. :-?

please forgive my ignorance, i am still in the beginning stages, but what do you mean by frequency of the ramp? slope of the signal is 1 means the equation of the signal will be " y=t for t>0 ", so doesn't it completely defines the signal? what other parameter do we need here? and i just wanted to check what will be the waveform across R and C for different values of R and C..so different values of R and C will only change the time taken by the capacitor to charge to the max voltage and since we have a ramp input which is continuously increasing,i don't mind if C takes little more or less time to charge..

 

[BradtheRad]

GBHT, there is an animated simulator you may find easier to use.
It's at the falstad.com website.

You can easily create moving oscilloscope traces.

I have constructed a circuit something like what you are doing. Here is the link. (I used two resistors. I left it for you to substitute a capacitor.)

Click Allow to permit the connection.

https://tinyurl.com/d5vbex7

You can edit components by pressing ctrl (maybe alt) key, and clicking on a component. After making changes it's a good idea to click the Reset button.

Directions are at the website. Also a large library of circuits you can try.

 

[FvM]

F(s) = 1/(s²*(1+RCs))