Claimed OU circuit of Rosemary Ainslie

[Rosemary Ainslie]

GUYS - I stated that 'results weren't out yet'?  Gross misrepresentation.  Poynty needs to check the link reference posted by Fuzzy.  We're nearly there Poynty Poynt.  Brace yourself.  I test down and 3 to go and THEN - you'll need to do some serious barrel scraping.

[Rosemary Ainslie]

Hi Wilby.     I'm learning more about you.  At last. LOL  Another couple of really excellent links.  Golly. That was really good.  Many thanks.  You see.  There's still hope for this thread - thank goodness.

And just watched the Dolphin bubble show.  That was really cool.  THANK YOU WILBY.  Definite mood lift.  Feel I can smile again with a little more conviction.

[poynt99]

The oscilloscope shots appear unchanged for the most part. An indication that Fuzzy's previous shunt resistor inductance itself may not have been contributing substantially to the skewed current/voltage phasing.

However, since a single-ended probe (assumed) is still being used, there is the ground lead still at issue, and I am somewhat curious where the ground lead is being connected; to the negative side of the shunt (assumed), or some AC ground point?

The probe location for the battery voltage should be indicated.  Where is the ground lead for this probe located?

A photo of the test setup would be appreciated, showing where the battery is and where the scope probes and their associated ground leads are located.

Any temperature readings, CONTROL tests etc? Or was this test simply to compare the shunt resistors?

.99

[poynt99]

Also Fuzzy,

Could you please post the model number of the probes you have (are they in fact the P6139A's?) and also what the length of the probe's ground leads are.

Thanks,
.99

[poynt99]

@Harvey,

It does not matter if the inductance is in the shunt resistor itself, or in the probe's ground lead, each plays it's own part in distorting the current (and hence power) measurement.

The shunt resistor can have 0uH, but unless the probe (even a diff probe) is placed directly across the resistor as close to the body as possible, it is a wasted effort to use this non-inductive resistor. Fuzzy needs to show exactly where his probe tip and ground lead are placed on this new shunt resistor.

The probe ground lead inductance has it's own set of concerns, and that is it forms a resonant tank with the probe's capacitance, causing ringing and phase shifts. This get's thrown into, and becomes part of the measurement. Once it's there, there is no distinguishing it from the true signal, and it will be the cause of an erroneous measurement of these transients.

Unless both these issues are addressed, the current measurement remains questionable.

Then there is the battery voltage probe, which I mentioned above. We need to know exactly where the probe tip and ground lead is located relative to the battery terminals.

.99