Testing the TK Tar Baby

[hoptoad]

snip..
The optoisolators work too well. They cause the mosfet(s) to switch cleanly and more precisely, if with a bit of slow turn-on.
...snip..

LOL - Damn those pesky things doing what they're designed to do, and doing it so well !!.

Cheers

[picowatt]

TK,

It is difficult to know which circuit/claim to test from all the ambiguities and versions.

Regarding the duty cycle I mentioned, I was indeed incorrect with regard to "seconds".

In an RA paper, RA states that "the offset of FG was set to its extremel negative limit".   Also, "the duty cycle is also set to the limit of the FG's shortest on time within each switching period of 2.7 minutes".  (Additional data like FG hi/lo open circuit voltage swing, duty cycle in absolutes, etc are not provided)

I believe this is the setup that RA and .99 were discussing regarding a test of COP=infinity and the scope shots I have seen discuused regarding same.  I could, however, be wrong, as there is a lot of "noise" out there.  Q1 is basically a small player (its Ciss does add to the AC current path during Q2 oscillations) and the Q2 array could have been just as easily biased on with a PWR supply through 50R.

I do not know the "minimum" ON time of RA's FG, but from her paper and at a 10% "on" time, that would be 16.2 seconds of Q1 "on" time alternated with and followed by 145.8 seconds of Q2 biased on time, ad infinitum.

Setting your FG to a long period and minimum duty cycle, output set to -15 volts open circuit during its lo period, and who knows what during the hi period (+5??) would likely produce similar results.  Depending on RA's FG "hi" period voltage setting, Q1 may have never been turning on.  RA states that no current flow was measured during the FG hi period, so possibly the FG output during that time was below the Q1 gate threshold voltage.

MH is correct about the variability of MOSFET capacitances with voltage, that complicates analysis/prediction a bit...  As per some of the RA statements, the FG's offset/level was used to tweak the oscillation/power level.  This would affect both the DC bias setting and vary capacitances a bit a well

At a DC bias setting below 300 ma, the pwr dissipated in the load resistor is minimal at DC, so I suspect the bulk of any greater power dissipated at the load would have been via AC curents from the oscillation.

Ever work on a 60-70's audio amp with a load connected and a dreaded AC oscillation screaming away?  Things get very hot very fast (until one of the outputs hang and then "poof").  Ah... the early days of discrete, those were the days...

PW





 

[TinselKoala]

I'm starting to get confused here. The Ainslie demonstration video shows their function generator set to produce a symmetrical square wave, negative going only, with a frequency of 10 Hz. This is confirmed by the shot of the Instek's panel, showing the figure "10" and some change and by the timebase of the scope shot (13) which is set to 40 ms/div, and the period of the FG's pulses is twelve minor divisions or 100 ms, as confirmed by the cursors (21, 20, 17). They claim in the video that this setting produces heating and battery recharging.  Where did these LONG periods come from that PW is referring to? 

I would much prefer to operate with the same parameters that they have actually _shown_. We know that their reports are unreliable, but scope traces do not lie. They may misdirect and provide cumulus-cloud-like material for projected imaginings, be rife with artefact and irrelevancies... but they do not lie. We know that much of what is "reported" by the NERD RATS is tainted in one way or another, by misobservation, improper interpretation of instrument indications, bad "calculation", math errors, anecdote and post hockery. This is why I tend to disregard everything (especially their "explanations") except what bits of raw reproducible data that can be gleaned from the dross.

Of course I _can_ operate at such weird duty cycles and long periods.... it's just a hassle with this analog scope I have here. And I don't want to generate miles of chart recorder paper like I did with Steorn's eOrbo farce.

Here, once again, is the scope shot from their demonstration, showing what they claim to be a fully operating NERD RAT device in oscillating, battery-recharging, load-heating mode.

Or will they  now claim that this does NOT show an operating NERD device.... ??

[picowatt]

TK,

The referenced RA paper is at the following:

http://www.overunityresearch.com/index.php?action=dlattach;topic=13.0;attach=6766

PW

[TinselKoala]

LOL - Damn those pesky things doing what they're designed to do, and doing it so well !!.

Cheers

I actually was able to get some oscillations while using the optoisolators. They are less consistent and make a more interesting (to me) pattern than the constant squeal of the certified Ainslie NERD oscillations, and are harder to "tune". I think that if I can figure out how to get the opto power and ground return from the main battery supply, this might help to reestablish the genuine NERD feedback. Also, of course the PG50s may behave differently.

Two scope shots showing the oscillations obtained _with_ the opto isolators: