buck boost

[Adam2014]

HI
through Analyzing & studying buck-boost circuit in continuous mode .
I need help or reference to find:
1.the initial value for each mode (on/off)
2. reverse voltage applied through the transistor and the diode ,,, and its maximum values
3. the input current equation depending on (1.)
4. use power conservation to find the initial value for input current
5. the maximum value of current into transistor

 

[dr pepper]

Heres an interesting site that doesnt sink you in equations:

https://www.dos4ever.com/flyback/flyback.html

 

[simonbramble]

if you are interested in analysing the classic 4 switch (H Bridge) buck boost converter, read the LTC3789 or LT8705 datasheets. You should be able to see that this architecture is nothing more than a buck converter (2 FETs running in anti phase) connected to a boost converter (low side FET and high side rectifier FET operating in anti phase). This will enable you to get your head around what the 4 switches do. I would suggest you use LTspice to simulate it, so you can probe around the circuit to get a real feel for what is happening. Download the LT3789 jig file if you want to get going immediately. See my website for LTspice tutorials