12v-24v to 230v smps inverter

[thameesha7]

Rogelio can you tell me please how do you do this calculation and what is your formular
how do you select wire awg valuve
how i am convert this awg valuve to swg
can you explane me your calculation please
thanks

 

[derrihj]

Voltage in

I think your Vin(min) should be around 21v to 22v since you have used Vin as 24volts in your formula.

 

[derrihj]

Hi
i need to make 12V-24V DC to 230V DC
inverter so i make one like this
i use Push-Pull topology and this circuit for it
http://2.bp.blogspot.com/-IGrcj4RjyY...cuit
+50kHz.png
and i use ER35 core
this is my formula Npri
http://3.bp.blogspot.com/-
vEX8Rr_RdD...alculation.png
i enter my valuve like this Vin(nom) = 24V, F
= 50000, Bmax = 1500(guass), Ae = 1.07
then my Npri = 8
and i want output like 230V 25W so i get
maximum duty cycle = 98% and my Vin(min)
= 11
so 0.98*11=10.78 and i get voltage ratio
(secondary : primary) = 250v:10.78 = 23.1
Nsec = N * Npri = 23.1*8 = 184.8
then my Nsec = 185
i get swg 26 as pri and swg 34 as sec
when i supply 12v my FET are not heat and
work fine
when i supply 24v inverter work but FET gone
heat
what is the wrong in my circuit can someone
help me please
(my english knowledge is not good sorry
about it)

I think you use Vin(min) as 21 or 22v since your Vin is 24v

 

[thameesha7]

i rewind my transformer using Rogelio's information then i supply 24v now fet has normal heat but 7805 regulator too heat more why it is heat more can i make this without heat
please help me
i only want 15w cfl light up using 24v so is there any another way for do that tell me please

 

[Rogelio]

What your purpose of placing a 7805 in your circuit? How was it connected?

 

[thameesha7]

ops i am sorry not 7805 it is 7812 it is connect for supply 12v to ic circuit

 

[Rogelio]

You don't need to place 7812 for the pin 13 Vs supply of SG3525 ic. You can connect 24V with 100 ohm series resistor to pin 13. SG3525 can handle supply 8V to 35V. Don't complicate your circuit by adding unnecessary components. See Datasheet of SG3525 for reference.

 

[thameesha7]

if i supply 24v to circuit directly pin 11 and 14 output voltage will gone high so if you think it is enough drive fet gate i think fet will be burn
i am don't know more electroni if i wrong please kindly help me

 

[thameesha7]

i change R10 resistor i replace 47k for that because i think transformer out is calculate for 230v and it is heat more i think i have to use 47k 1w resistor it is right

 

[Rogelio]

if i supply 24v to circuit directly pin 11 and 14 output voltage will gone high so if you think it is enough drive fet gate i think fet will be burn
i am don't know more electroni if i wrong please kindly help me

Just try it. Then observe. Be sure to place 100 ohm in series for the +24V for ic.

 

[thameesha7]

thanks every one specialy Rogelio thanks bro my inverter is work fine

 

[Rogelio]

Your welcome.

 

[GEORGEOS]

me too, I'll say thanks to Mr. Rogelio, And will ask him to do the same calculation for transformer primary and secondary to get 100 W output capacity in two cases:
case 1 trafo type is ERI 35
case 2 trafo type is EEI 35

Best regards