i need ur help
i m going to design 60 watts power supply with 4 multiple outputs. The specification s given below.
Dc to DC converter.
Input voltage = 170 V to 450Vdc
Outputs; out1:5v/1a
out2: 12/2a
out3: -12v/1a
out4: 12v/1a
My questions are,
1) I designed the power supply in singly switch flyback topology.But now due to high input voltage,i cannot find out the mosfet in 1300 V (its too high). so decided to got to TWO SWITCH FLYBACK topology.
a) All the parameters are calculated for single switch, so what are all the parametrs changes when we go for two switch flyback?
b) Is two-switch flyback advantageous compared with single switch?
c) I can not find the design example and equation for the two switch flyback, can you suggest some papers?
Comments
Ya. you could know this already. In-order to reduce the voltage stress across the mosfet in flyback converter,we choosen this two-switch flyback converter for our application having wide range input voltage 170-450V DC input.
It has following advantages ,
1) due to stress across the mosfet reduced,the conduction loss is reduced, bcoz Rds on resistance is proportional to the BVdss.
2) Them EMI reduced.
3) But the disadvantage is, two-switch rather than one,individual switch pwm control signal should be isolated.
find the attached converter diagram
I see what you mean. Top switch is not a suitable to be used in bridge topology because you cannot synchronize them.
You may take a look to the hipper family for your application
Could you please be more specific when you say " two switch flyback "
can you please post an schematic of this implementation for us to understand better?