another small breakthrough on our NERD technology.

[picowatt]

TK,

In the scope shot you posted "bigheatann1", that screen appears to be from March 2011.  Is that correct?  What is the date?  I can't see past one of your reference lines.  Q1 appears to be functioning in that capture.

Also, can you tell what the postive voltage is for the gate drive trace and the CSR trace value in that capture?  It looks like about 8 to10 volts to the gate and the CSR trace is indicating about 2.4 amps (about .6 volts across the CSR).  Do you agree?

PW

[picowatt]

TK,

Did you just now do that test?

Dang,

PW

[TinselKoala]

TK,

In the scope shot you posted "bigheatann1", that screen appears to be from March 2011.  Is that correct?  What is the date?  I can't see past one of your reference lines.  Q1 appears to be functioning in that capture.

The date is the 12th March, 2011, the date of the demo. I think this is a "live" capture, not a stored memory trace like the ones in the papers.

Also, can you tell what the postive voltage is for the gate drive trace and the CSR trace value in that capture?  It looks like about 8 to10 volts to the gate and the CSR trace is indicating about 2.4 amps (about .6 volts across the CSR).  Do you agree?

PW

Gate drive looks like about  8 to ten V to me too. My items 14 and 15. Cursors... foiled again. When I made the annotations I measured as best I could and that's about what I came up with too (but I can't find my annotation captions right now...)
The CVR trace looks like at _most_ 1 and a half minor divs above baseline, for a voltage of 1.5 x .5 or 0.75 V which would be around 3 Amps.
This is one of the very few scopeshots that shows the mosfet common drain trace, the green trace. You can see the voltage drop there as the Q1 mosfet turns on with the positive gate pulse.

[TinselKoala]

TK,

Did you just now do that test?

Dang,

PW

Yup, and it's still running, load oil is at 104 F, inline ammeter 190 mA, batt voltage in-circuit 36.4 V, opencircuit 36.7 V.

My load cell consists of the resistor load, inside a "Fleaker" flask of 300 mL nominal capacity, with 250 mL USP mineral oil. This is capped  with the Fleaker's heavy rubber cap, the wires leading thru drilled holes in the cap, ditto the thermometer. This Fleaker is wrapped with a double layer of thermal barrier material and inserted into a larger 1 L standard beaker which is itself wrapped with a half-inch thick layer of heavy foam rubber material, and then there's a little cap of the thermal barrier stuff for the very top. It's a pretty well-insulated system, unlike what Ainslie used: the naked water heater element.
I have a water heater element that I can use, but just hanging it up and measuring its temperature in the air somehow seems wrong.

[picowatt]

TK,

Excellent write up of that last test.

So, I am now more confused as to why Q1 seems to be performing as expected sometimes, and not so much at other times.  In the captures where Q1 does not seem to be turning on, the gate drive appears higher than the captures where Q1 is obviously functioning.  The higher gate drive should turn it on harder.

Any thoughts?

PW