# Urgent: Series LC Resonance in PSPICE !!!!!!!!!!!!!

Discussion in 'General Electronics Chat' started by Management, May 13, 2009.

1. ### Management Thread Starter Active Member

Sep 18, 2007
306
0
Can some people help me with this please?

I want to model the coil on the left and what I currently have is what is on the right.

I probably should add some switches to model the ac voltage applied to the coil but lets just say the coil is closed and the L's & C's should resonant at 64 MHz and cause some current to be flowing around in the loop, correct?

From an LC calculator, @ 64 MHz and a C value of 30 pF, the L value required for resonance is 206 nH. As you can see the values of the C's, when you set the value of the inductors, 2 for each transformer, I set them all to 206 nH. Was that correct?

How can I see that they are resonating at 64 MHz? Did I place my GNDs and that 1 Ohm resistor in the right place?

I only put those 100 Meg Ohm resistors because PSpice kept telling me that 8 nodes were floating. Did I even need those?

Some serious and quick help on this would be appreciated.

Thanks.

Sep 18, 2007
306
0
No takers?

3. ### Management Thread Starter Active Member

Sep 18, 2007
306
0
The coil on the left is exposed to 250V @ 64 Mhz of RF voltage. To get current running through the coil, the coil is tuned to resonate at 64 MHz. When it is de-tuned then the coil is "invisible". I'm just looking at the tuned aspect.

I figured that this would be a good way to model it in Pspice but I guess I'm wrong. Right?

What I wanted to be able to do later was add a switch in the "coil" loop. That adds some high impedance, isolation, and de-tunes the "coil" and no current runs through the loop.

How can I make this transformer setup work? The traces of the coil should be modeled with inductors and the total inductance is 206 nH. One inductor in each corner yields 51.5 nH. Each Capacitor is 120 pF. This should resonate the coil at 64 MHz and cause significant current flowing through the coil, correct?

Does me setting my transformer inductances to 51.5 nH give me that? For each transformer both inductors are set to 51.5 nH to have a complete transfer of energy.

I should change those caps to 120 pF each as well.