Q3 is backwards, you need to connect emitter to minus and add a resistance on the collector. You are back biasing the transistor, an unpredictable state.

You could reverse it a bit like so...

Use 6.2V zeners. They will prevent shoot through. I have never tried this circuit.

One thing that stood out was polarity of the transformer, you need to be very careful there.

i couldn't make it..it's not working could u pls try it in your simu program? i'm reallly desperate now... if i cant do this i cant graduate...

 

Sorry guy, my simulator is between my ears. If I need to check a circuit out I draw it up thusly and then build it...

Just a suggestion, stick some resistors that would allow your circuit to dissipate the same wattage instead of the transformer. Like I said earlier, inductance doesn't really enter into this as much as you think. If their isn't a load on the output side the input side (via counter EMF) is basically open. A transformer isn't a coil in the classic sense, it resembles a motor more. If there is a load on the secondary it is feed through, if there is no load then the input of the transformer will absorb almost no current. This is a counter EMF phenomenon, not an inductive one.

 

thanx man for everything but i think i cant do this circuit with simulator...i tried so many things but its not working..

 

Have you replaced the coils with resistors in the transformer area?

 

if you say i replace resistor to output yes i did...

 

Like this?

 

its working man thanx but still i have problem with transformer.. i write 1:2000 its working but i have 100mV output and it doesnt like square wave what propotion i need to write...

and could you pls write why you add zeners (CR1, CR2),diodes(CR3, CR4) and resistors (R3 and the last two)..do u have formulas for that...

 

Does anyone send me a link which is about transformer design pls?... deadline is tomorrow i need to design the transformer today...

 

Just a suggestion, start a new thread in the homework forum. Use everything you have here, and list the SPICE software you are having problems with.

This thread is in the projects forum, so everyone concentrated on the circuit. It sounds like you are having problems understanding and using your SPICE package for a homework assignment.

 

thank u man..i'm doing it right now...