# Drawing Out in ORCAD/PSPICE

1. Nov 14, 2011

### mod31489

I Need to draw this out in pspice and I'm having trouble accomplishing this.

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2. Nov 14, 2011

### Staff: Mentor

Welcome to the PF.

What part are you having trouble with? You will need to figure out the inductor values -- you will need to work backwards from their impedance and the frequency of interest.

3. Nov 14, 2011

### mod31489

I'm having trouble converting the inductors back to hertz, I learned how to do it in a circuits class several years ago but I'm pretty rusty at it and am having difficulty figuring out how to do it. Also when drawing it in pspice the middle row of resistors and inductors runs straight into the middle of the resistor, does this mean i attach that to the end points of the inductor? and lastly are the 125V sources in the scematic and what does the other side of the circuit look liike I know the 14kV is just a 14kV dc source but is there any resistors or inductors on that side?

4. Nov 14, 2011

### Staff: Mentor

I believe that the "125V" notations on the secondaries are to tell you the turns ratio of the ideal transformer. You don't add in any other voltage sources there.

On the main input voltage source, just use an AC source. I don't know if SPICE will throw an error with an AC source connected directly only to an inductor (the jprimary inductance), but if it does, just add a high value resistor in parallel with the primary of the transformer.

When you convert the phasor notation for the inductors to their actual inductance (in Henries), you use the formula for the impedance of an inductor versus frequency. If you don't remember that formula offhand, you can just Google the phrase to find it.

I didn't understand your comments about the middle leg of inductor + resistor running into the middle of a "resistor". Do you mean where they are connected to the center tap of the transformer secondary?

5. Nov 14, 2011

### mod31489

yeah the way they are connected to the center tap of the transformer secondary...i dont know how to draw it in spice

6. Nov 14, 2011

### Staff: Mentor

7. Nov 14, 2011

### mod31489

Thank You, you've been very helpful and I was just wondering one more thing, how would i solve for r1 r2 and r3

8. Nov 14, 2011

### Staff: Mentor

That would depend on what the original problem statement was, or on whatever your goals are for the circuit.

9. Nov 14, 2011

### mod31489

Thanks, I just read through the original problem again, it was mentioned in the very fine print