Not going to be that simple -- Laplace transforms are for linear circuits and that diode makes it nonlinear. Also, modeling the switch with a transform isn't going to be easy.Laplace transforms ...
This is a sufficiently advanced problem that you should have at least some ideas on how to start doing something one it.
The circuit is kind of DC converter.This is a sufficiently advanced problem that you should have at least some ideas on how to start doing something one it.
Can you explain qualitatively what the circuit does and how it does it?
What kind of model are you using for the diode?
What if the problem was simplified and just asked you to find Vo(t) after the switch is closed (and remains closed)?
Hi,Not going to be that simple -- Laplace transforms are for linear circuits and that diode makes it nonlinear. Also, modeling the switch with a transform isn't going to be easy.
Hi,
I have learned how to solve boost,buck and cuk converter.Hi,
First, "I NEED HELP" is a really bad choice of thread title. It is obvious that anyone who posts here needs help and you are supposed to use a more descriptive title.
But as to the solution, what techniques have you learned in the past, such as averaging techniques or something? What kind of converters have you analyzed in the past?
Hello,I have learned how to solve boost,buck and cuk converter.
We draw the figure of current and voltage with straight line.(using L*ΔI/Δt = V)
I don't know if it is averaging techniques.
sorry for the title.But, it seems that I cant change the title as I post the thread.
ya it seems like that.
Hello,
Well then maybe you could show some work with what you did with the Cuk or maybe the boost and buck too. That way we know what method is acceptable for you.
At least show the work for the boost but since the Cuk is somewhat similar that would be good to show your work for also.
Hi,here is what I did to solve a boost converter
View attachment 196249
And this one is the job done to the buck converter
View attachment 196251
Looks like it add inductor and capacitor to the buck circuit.
I found that cuk is kinda different from boost and buck,as I solve it with capacitor current rather than inductor one.Hi,
Ok great, and yes that is averaging, however, we still need to see your work on the Cuk. Those two circuits can both be solved by assuming the switched state of the diode, while the Cuk may require that you solve for that too. So i'd like to see how you worked out when the diode is on and when it is off so you can write the averaging expressions. Perhaps you were able to come up with some reasoning that allows you to assume the diode state.
So seeing the work you did on the Cuk would help a lot here.
Hello again,I found that cuk is kinda different from boost and buck,as I solve it with capacitor current rather than inductor one.
View attachment 196300
I am wondering if I can apply the same thing to my problem.
Ya. My classmate found the diode act like what u said using mathlab simulation.Hello again,
Ok that's interesting. With the Cuk your work shows that the diode switching states are synchronized with the actual switch switching states. That means that you can choose whether the diode is on or off based on the switch switching state and that means we have two distinct modes of operation:
1. Switch on, Diode off.
2. Switch off, Diode on.
This makes it easy to solve using several methods.
How
However, in this new circuit, the subject of this thread, the diode switch state is only partially sync'd to the switch state. We actually end up with three different modes of operation:
1. Switch on, Diode off.
2. Switch off, Diode on.
3. Switch off, Diode off.
So it looks like when the switch is off you will have to find a way to determine when exactly the diode is on and when it turns off . It seems clear that the diode turns on when the switch first turns off, but it is then not as clear when the diode turns off.
So the main question is, can you determine when the diode turns off when the switch is off?
(That would be some time during mode 3).
Hi,I got stuck here as I don't know how to determine when the diode turns off.
View attachment 196326