SMPS dc ac 150w design problems

[lucasrg]

Hi,

iam new to this forum so i would like to say Hi to every one on this forum.

I have been trying to put together a inverter with little success. first i put together the design made on the tahmidmc blog https://tahmidmc.blogspot.com/2013/01/using-sg3525-pwm-controller-explanation.html in this blog he explains every thing related to the design of this push-pull design. After getting this to work (getting some output voltage) i started to put some resistive loads to test how much power can this put out and i realised that i was getting very little output. I started verifying the control loop and i can se that the voltage drops dramatically on the voltage divider putting the PWM on 48% all the time and even with this it can not reach the desired volta output.

what can i do to get this to work or what is this design missing so i can star building confidence with this type of circuits.

i like to work with hydro power and solar as hobby and i am always in need of a inverter because the commercial always get burned out and maybe with my own i can fixit more quickly.

regards

 

[kam1787]

If the commercial units always burn out, I suspect you are doing something very wrong. Maybe it would be better to find out why those burned out first.

 

[lucasrg]

the got burned out because of a grounding problem but i have sorted that out. my point was that they aar very hard to fix and almost every time the PWM chip is the one broken along with the dc input mosfets.