As promised, some measurements using my little VNA on my received 0.1 Ohm bare metal csr (see picture 1) as used by CaptainLoz during his COP=2 measurement.
I am using the "Shunt-Thru" measurement method with the VNA as that is the preferred one for doing impedance measurements on low Impedances, see the below attached PDF.
I build a test fixture so to be able to use as a reference plane initially the csr resistor only, so not any connecting pcb traces, pins and scope (ground) leads.
For reference plane see:
https://zone.ni.com/reference/en-XX/help/373153D-01/vnahelp/reference_plane/The screenshot-1 below shows the major values like inductance (nH), resistance (mOhm) and reactance (mOhm) of this 0.1 Ohm csr ONLY, so without PCB etc.
Sweep was from 10KHz (minimum) to 10MHz, markers at 1) 800KHz, 2) 5MHz and 3) 10MHz.
Marker 1 shows the operating frequency of the CaptainLoz device (800KHz).
It shows the inductance ("Series L" = 35nH) stays stable across the sweep frequency.
The resistance ("Series R" = 101 mOhm to 239 mOhm) shows an increase with frequency
The reactance (Z= 210 mOhm to 2.2 Ohm) shows the expected increase due to inductance/frequency.
So the values at the 800KHz working frequency shows a 2 times (210 mOhm) higher impedance then expected from this 100 mOhm csr at DC.
Something member "Picowatt" already mentioned months ago here:
https://overunity.com/18617/rant-caffe-asylum/msg551145/#msg551145So when using this csr AND when measuring the voltage DIRECTLY across it using an RF probe, then the registered voltage should be taken times 5 to correct for the 0.2 Ohm csr, NOT times 10 (for a 0.1 Ohm csr).
But.... as CaptainLoz was NOT using an RF probe, but instead a normal voltage probe with long tip and ground leads AND using a PCB with copper traces, connection pins etc. see picture 2, there will be a large extra inductance and resistance thus impedance to be accounted for, see picture 3.
The 2th screenshot then shows the values taken with such an extra PCB where the csr was mounted on and measured with a normal voltage probe/ground lead.
It shows the inductance ("Series L" = 169 to 153nH) across the sweep frequency.
The resistance ("Series R" = 136 mOhm to 2.3 Ohm) shows an increase with frequency
The reactance (Z= 874 mOhm to 9.8 Ohm) shows the expected increase due to inductance/frequency.
So at the 800KHz working frequency, the 0.1 Ohm at DC csr now measures as a 0.874 Ohm csr which is almost 9 times higher as expected.
So instead of using a 1:10 correction to compensate the scope for the 0.1 Ohm csr, we actually need to use only a 1:1.1 correction.
This could mean that the current fed into the scope math function was 9 times lower which probably will result in a 9 times lower power calculation, so instead of the calculated 38W output it should be more like (38/9=) 4.2W.
Of course there could be some differences in used probe tips/leads and pcb connection etc. so my measured value's will differ from CaptainLoz his, but it won't be much.
Hopefully when the Captain is ready to do some testing with me (
https://www.overunityresearch.com/index.php?topic=3951.msg85440#msg85440 ) we can sort this out and either provide me with a COP = 2 device or show the Captain where he went wrong.
Regards Itsu
Author
Topic: Itsu's workbench / placeholder. (Read 137458 times)
