learning about smps , somebody help me

[horizonrays]

hello friend ,
i am just learning about smps ,
so i want to know the difference between these three topologies , when driving the gate transformer
what are differences , what are benefit what are demerits ?

here is the attachment ,

,

and also the difference between driving these ,




thanks you ,

 

[MicrosiM]

Images are very small to see what you are talking about

Please post better images!!

 

[horizonrays]

Thanks for reply , I am rewriting my questions along with new Pictures .

Here are a few questions I would Like to ask :--
1> What's the difference between Driver A and B , I have seen many half bridge SMPS schematic and some use a kind of driver and some use b , I would like to know the basic differences , which one to prefer over other and why ? Which one is more efficient ?

2> Second Question is regarding Snubbers , what is the difference between Snubber A , B , C . Which One is Better and why ?

3> How to calculate Optimum Snubber Resistor and Capacitor Value For Both Step Up and Step Down Half Bridge SMPS design . (Formula Is needed )

4> How to minimize leakage inductance in the SMPS transformer.

5> Many commercial smps do not have any gap between the core , is it necessary to have Gaps in between core if we are dying ?

I would be glad to receive the replies from smsps masters .

 

[szhighstar]

To reduce leakage inducance, you can wind all coils using sandwich method for tansformer, try to reduce transfomer volume, coil is smaller, leakage inductance is more smaller, several strands wire to parallel winding which replaces a big diameter wire.
If it is flyback transformer, the core must has air gap, if it is forward transformer,the core is without air gap.