Magnapack

[tinman]

For some time now i have been messing around with transformers,using magnetic core's.The one described below is the best results so far.The schematic preaty much says it all,in reguards to this setup,except the transformer configuration itself.In reguards to the scope shot's,the yellow trace is across the input resistor,and the blue trace is across the output resistor. The transformer is a 1:1 bifilar type,and has a magnetic core,but not aranged the way you may think.
Although this is more than likely wrong,it seems we have .0158 watts being disipated across the input resistor,and .0363 watts being disipated on the output resistor. You will also clearly see the phase shift between the primary and secondary-maybe due to the high frequency,or the magnetic core?
MH and TK-i would like your opinion on this one.

[tinman]

I forgot to mention that the frequency needs to be fairly close to right,or we dont get good result's. In the below scope shot,i have thrown the frequency out,and it now clearly is using more power than it is outputing.

[tinman]

In the below scope shot,i have replaced the 3 ohm resistors with .1 ohm 5 watt CSR's.Everything else remains the same. The results seem to be better with the lower resistance CSR's.
Im not sure what the noise is you see on the wave form to the right of the scope shot.It seems to flow through the wave's from left to right on the scope-kinda looks like small explosions in the wave forms.
I also had to raise the frequency with the lower resistance,to gain maximum amplitude on the output wave.

[MileHigh]

Tinman:

It's worth it to take a fresh look at this and I will give you a few pointers.

Comparing the power dissipated across the "input resistor" to the "output resistor" is unusual and I fail to see how useful that comparison is.  Look at your schematic; the input power to the circuit is supplied by the signal generator so you should be measuring that.  That input power goes to two places, R1, the "input resistor" and the transformer primary.  So the "input resistor" is just one load among other loads that dissipates power supplied by the signal generator.   The primary of the transformer looks like another load to the signal generator.  That primary couples power to the secondary, and that power gets split between R2 and R3.  In addition, each winding of the transformer has a 0.5 ohm equivalent resistance and those are also dissipating power.

With the understanding of where the power is flowing, what is a meaningful comparison?  Perhaps the input power from the signal generator compared to the power dissipated in R2 and R3?  That's for you to decide but I don't see any merit in your original approach of comparing the power dissipated across the "input resistor" to the "output resistor."  I see the input power from the signal generator being dissipated into five resistive loads (including the winding resistances.)

You are working with sine waves so you are supposed to measure power across resistors based on the RMS AC voltage.  By the same token, you want to look at the phase angle between signal generator voltage and the signal generator current to measure the input power to the circuit.  You also might be interested in seeing how the phase angle (and therefore input power) varies with frequency.

MileHigh

[tinman]

Hi MH
Well im using the .1 ohm CSR's now-is this not how a DMM work's?. From the voltage across resistance,can we not calculate power?
Below is the mod schematic,and scope shot with RMS value,s.