Need help in multisim 11? I want to get the transient response of RL circuit....

[praga]

Need help in multisim 11?
I want to get the transient response of RL circuit....i can get the increasing exponential graph in multisim 7 during simulation.....but i am getting a decreasing exponential curve(i.e,decay response) in multisim 11 when i do the same procedure as i did in multisim 7.....how can i get the initial or growth transient response for RL circuit in multisim 11 so that i can get increasing exponential curve....which satisfies time constant = L/R

[Miguel_V]

Hello!

A properly set-up transient analysis or oscilloscope should be able to provide you with the information you're looking for. I have some information on setting up a transient analysis as well as a lab to follow if you need guidance on the process (ignore the NI Elvis requirement, just set up the parts on multiSIM and follow it). Incase you can't resolve the issue, it would be helpful for me to see the circuit that you are talking about so as to help you more. You can PM it to me or post it, your choice.

Laboratory

http://www.ni.com/white-paper/4944/en 

Analysis Tutorial

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA03q000000YH7lCAG&l=en-US

[praga]

pls refer this attachment

[Miguel_V]

Hello,

The process is the same for any circuit (in this case it is an RC circuit which you sent me). You can find the response on the voltage (which I think it's what you're looking for) at any point of the circuit, as well as any parameter really (R,V,I,L..etc).

Please refer to the image attached (an analysis on the voltage at an inductor and the wires connected to it).

The way to set it up (once you're in the transient analysis set up) is, select the Output tab, under Variables in circuit, you can select which parameters to take. V(1) and V(2) refer to the voltage in the circuit at Net 1/2 (or wire 1/2).

This differs from the voltage change within the capacitor/inductor/resistor. If you would like to see the voltage change of an inductor/capacitor/resistor/etc, you can select under the More options box, the button Add device/model parameter, which will take you to a window to select the device type, its name (in the circuit) and the parameter which you wish to analyse. Once you click on Simulate, you can select Cursor >> Show Cursors, to view information for y and x axis (like rise time, decay time, voltage difference...etc)

Hope this helps,

[praga]

hi sir...

in my college ...dey are asking me for a plot between time and current....they taught me in multisim 7 and when i do  the same in multisim 11 ...iam getting an increasing exponential curve for rc and decreasing exponential curve for rl....but actually...what the required response tat i needed is an increasing exp curve for rl and decreasing exp curve for rc.....plot b/w (I) and t....

[Miguel_V]

Hello,

I found out why you are getting that response in your circuit. I made an RL circuit myself and it seemed to work perfectly. In your case, it is the voltage source. Try either of two things, either flip the terminals of the voltage source (you can do this by disconecting the wires, selecting the source then either rotate it with ctrl+r, or flipping it on the y-axis with alt+y), or switch positions with the resistor in the circuit. Then do a transient analysis again.

Cheers,