Transformer Design

Hi.. i have design a inverter circuit 12Vdc / 220 Vac 20W... i'm doing it in a simu program (Pspice) but i cant get the signal from output.. i need the inductance formula of transformer.. could u send me the formula pls? if there is something wrong in my design pls say it too.. circuit is this;

Flip Q3 vertically and connect a 1K resistor between its collector and the base of Q4.

Hello,

Here are two links :
one from epanorama :
http://www.epanorama.net/documents/components/transformers.html
And one from electricianeducation :
http://www.electricianeducation.com/theory/electric_transformers.htm

They are talking abou the inductance of a transformer.

Greetings,
Bertus

PS here is hoe i found the links :
http://nl.altavista.com/web/results...la&aqo=&aqn=&kgs=1&kls=0&dt=tmperiod&d2=0&dfr[d]=1&dfr[m]=1&dfr[y]=1980&dto[d]=28&dto[m]=12&dto[y]=2008&filetype=&rc=dmn&swd=&lh=&nbq=10&stq=10

mik3 said:

Flip Q3 vertically and connect a 1K resistor between its collector and the base of Q4.

Click to expand...

thank you i did it but still i dont know what i write to primary and secondary number...

i have found a formula that is;

L = N^2 * μ * A / l

L = Inductance of coil in Henrys
N = Number of turns in wire coil
μ = Permeability of core material
A = Area of coil in square meters
l = Average length of coil in meters

i calculate the primary and secondary inductance with this formula and write it to simu program but still it isnt working.. what am i going to do right now i have no idea... pls help me

Could anybody verify this formula?

I can't help a bit with the PSPICE, but the relationship of inductors to transformers is slim. They don't model that way. The addition of the second coil tightly coupled to the first changes its whole character.