Hi
Madcow, i agree with you that -200v is reflected back to the primary.
However, if diodes D1 and D2 of 2nd page, fig 5 of following
http://www.edn.com/contents/images/47173.pdf
...were on during the off-time of the Mosfet switch's then this would not be possible -since it would be 400V...
If for example as a 2 switch flyback…..
Np = 100
Ns = 10
Vin = 400V
Vout = 20V
…………………………………………..
When mosfets go off…..
Secondary starts conducting.
Vs / Ns = d(phi) / dt (1)
At the same time the primary is conducting through the diodes.
Vp / Np = d(phi) / dt...
I thankyou for this reply, and i am still concerned since as you rightly point out, there is a reflected voltage on the primary from the secondary which happens when the switch is off.
The thing is, the primary can only have one voltage across it at any one time......not two different ones at...
Hello,
I am requesting your assistance if i may as i must make a DCDC converter to have V(in) = 400 Volts and V(out) = 12 Volts.
The high V(in) makes me want to use a 2 switch flyback, as in the following article......
http://www.edn.com/contents/images/47173.pdf
...the two switches, and...