Dot convention for power converters

Hello,

I'm new to this forums and I have this problem with dot convention when working on power converters, more in specific where SEPIC, Cûk,ZETA, etc, are involved.

I understand this: "If the current enters the dotted terminal of one coil, the voltage will be positive at the dot on the second coil"

So with voltage is a bit clear but for  example what happens on a SEPIC converter where most manufacturers place the dot at ground point?, also how the voltage is not inverted by supplying both voltage and current to the load???

I'm sorry if this is stupid but it has been driving me nuts for some time here is a typical circuit:

I believe it just means the orientation of the winding,so as to indicate the direction of flux, phase offset, etc.

This article may help explain things better.

http://electronics.stackexchange.com/questions/6657/what-do-phase-dots-on-an-inductor-mean

JHW 3d said:

I believe it just means the orientation of the winding,so as to indicate the direction of flux, phase offset, etc. This article may help explain things better.

http://electronics.stackexchange.com/questions/6657/what-do-phase-dots-on-an-inductor-mean

Click to expand...

Thanks for the link however one of my friends had an experience with a SEPIC two months ago, he just winded the coil the same direction, then when probing the converter, the FET we were using as a switch exploded, well not that intense but yes kind of. Still puzzles me...

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