12-300v push pull voltage booster

[ATIKU]

Thanks for always

Pls, I planned to make DC to DC 12v - 300v voltage booster using push pull configuration.

So now, my push pull secondary side us outputting voltage rating 900ACV, then I use UF5804 in form of bridge rectifier with additional 450v 47uf capacitor

But unfortunately my DC output is around 50DCV, which is very wrong

Pls help, am confused

 

[Magnethicc]

Please add schematic & X'mer specifications.

 

[cupoftea]

Do you need isolation?...if not then just use the cascaded boost converter.
If isolation, then do you closely couple the two primary halves?
Do you use voltage mode?...then beware flux walking.
What is your output power?......beware if it is large then your input current will be very large and high rdson in the pri fets will do no good and will mean you need much bigger turns ratio.

Evn with max 0.7 duty cycle you will need np/ns = [300V/0.7]/12V = 35:1....coupling likely to be poor and big snubbering needed pri and sec.

You might even prefer to dual cascaded boost up to say 100V to 200V or so, and then voltage mode half bridge to go 200V to 300V.

But what is power level?.....if it is 500W then your input current is 500/12 = 42A...you could well be getting big resistive drops in the pri side.

 

[tuchichi takkaida]

Schematics are the language of electronics, please show us what you got.

Please note; the schematic should reflect exactly what you have built and tested.

 

[ATIKU]

Do you need isolation?...if not then just use the cascaded boost converter.
If isolation, then do you closely couple the two primary halves?
Do you use voltage mode?...then beware flux walking.
What is your output power?......beware if it is large then your input current will be very large and high rdson in the pri fets will do no good and will mean you need much bigger turns ratio.

Evn with max 0.7 duty cycle you will need np/ns = [300V/0.7]/12V = 35:1....coupling likely to be poor and big snubbering needed pri and sec.

You might even prefer to dual cascaded boost up to say 100V to 200V or so, and then voltage mode half bridge to go 200V to 300V.

But what is power level?.....if it is 500W then your input current is 500/12 = 42A...you could well be getting big resistive drops in the pri side.

Thanks a lot