Hi!
I downloaded Qspice a day ago and I could not find a way to simulate voltage rated capacitors. How do I do it?
Thanks in advance!
What exactly are you aiming to achieve in referring to simulate a capacitor with a voltage rating?
In simulation, you can apply any voltage value, and the capacitor formula will still hold true. However, in reality, there is a physical limit beyond which the capacitor will be damaged.
The purpose of simulation, is to assist engineers in understanding your circuit before you building it. For example, how high the voltage can be across devices, this enabling them to select the appropriate components or design circuits to prevent overloading the physical components.
In my experience Voltage rated capacitors perform very differently from a capacitor without it in the simulation. This is something that I noticed during my use of LTspice. For example if I have a full wave rectifier and have a capacitor for smooth out the ripple, a voltage rated capacitor can have a small value while providing smooth output. On the other hand, a capacitor without the rating needs that have a higher capacitance for achieving the same smoothness.
I would like to know if Qspice has different characteristics for voltage rating when running simulation. This is the reason behind the original question.
Interesting… well, I just quickly perform a testing in LTspice, where C1 and C2 are both 1uF, with C1 set voltage rating to 100V (i.e. with instance parameter V=100). But I cannot see any different in their current in response to input voltage. Is there certain setup can make a different if voltage rating has value set? As from my impression, the instance parameter “voltage rating V” is only for display purpose and have no effect in simulation. But based on your input, it seems I am wrong but the problem is that I cannot observe different with and without this value from the simulation setup.
This rectifier looks identical whether the voltage rating value is set or not in capacitor.
And in this reference, instance parameter V is for BOM only and not used in simulation.
https://groups.io/g/LTspice/message/151577
I see what I did wrong. There are two things that caused this discrepancy
- I always assumed that the components after the rectifier and the Capacitor will have same resistance as the generic load used during the simulation of the rectifier. It had nothing to do with the voltage rating of the capacitor. Often time this new resistance due to component is lower than the simulated resistance, therefore, lowering the voltage.
- Its silly but in some places I did change capacitance, which actually caused the error in the first place. Once again this has nothing to do with the voltage rating.
I really appreciate for all the support. I will consider this issue to be solved.
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