Push pull topology using SG 3525

[pakkiboy]

Dear members , I have designed push pull converter using SG3525 for pure sine wave inverter ( this is first step for it ) with specs
Input Voltage = 12 V DC
Output voltage = 300 V DC
transformer = ferrite core
Mosfets = IRFZ44N
( i didnt used any inductor at output after rectification , just used capacitor for filtration purpose )
Mine main problem that it work well under No load condition , but when i connect it to any load , a very sharp voltage drop occurs ( form 300 DC to even less then 100 V DC ) as i have used already built in feedback in sg3525 . Can you plz help me . I shall b very thankful to u all
Circuit Diagram
https://obrazki.elektroda.pl/3757925700_1379687360.png

 

[Audioguru]

When the inverter is loaded, does the 12V drop to 4V?

 

[pakkiboy]

voltage at high side of transformer drops , and large current flows , as a result input voltage also drop to about 8 ( approx )

 

[pradeep.g.belchada]

their is a problem in your battery

 

[pakkiboy]

No sir , i have used both power supply and battery ... but same issue , i think there is some problem in feedback ,,, do u think ????

 

[pradeep.g.belchada]

if yo used 12v 50ah battery for testing then in any condition its voltage will not drop to 8v

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if inverter draws a large current more than 50amp then also voltage will not drop to 8volt.

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faulty & weak battery's voltage will drop

 

[Audioguru]

If the power supply or battery voltage drops then the power supply or battery cannot supply that much power.