Hello all, I am a first year electrical engineering technician student and currently working on my final assignment for computer applications class. I was given three hand-drawn circuits and have to draw them in AutoCAD and build them in Multisim, do a simulation and record my observations in excel and microsoft word. They are basic circuits with a two resistors, a switch and a capacitor. The objective of the assignment is to show the difference in charging times for the capacitor with different resistor values.
Some of the marks for the assignment require oscilloscopes to be connected and working to show the charging for the capacitor. When I connect the A channel across the capacitor and run the simulation with the switch in a position that should not be allowing the capacitor to charge, the oscilloscope shows that it is charged. Therefore it is not demonstrating a charge/discharge cycle. However, on my other two circuits below the one I just mentioned I have connected voltmeters across the capacitors in the same way, along with oscilloscopes. Now when I run the simulation I get the desired result on the oscilloscope, with the charge/discharge showing when I operate the switch. Why is this? Am I missing something? All that is changed is an added voltmeter. I appreciate any help.
I also am wondering why I am getting a voltage of 0.909 volts across the capacitor when it is not charging?
Thanks very much. I have attached my multisim file.
This is happening because you are using the default settings of the Interactive simulation. To see how the capacitor charges, you have to modify the simulation settings. Follow the link below for further information.
How Do I See the Charging of a Capacitor in Multisim?