Testing the TK Tar Baby

[picowatt]

Did it yesterday, 2800pF each side. Rgen=50 Ohm.

Works now, but the turn ON and OFF of the burst envelope are much slower, so I have to lengthen the run time.

.99,

Dang cross posting.  So, you beat us all to the punch line.  Always gotta' save that punch line to the very end.

So, are you saying that the burst envelope of the sim is slower than the NERD waveforms?

Next question, can you tell what values are being used for Coss in the MOSFET sims?

PW

[picowatt]

Did it yesterday, 2800pF each side. Rgen=50 Ohm.

Works now, but the turn ON and OFF of the burst envelope are much slower, so I have to lengthen the run time.

.99,

Is this sim your single MOSFET burst osc or the NERD circuit?

What freq of osc did you end up with?

PW

[MileHigh]

I hope Rosie Posie is taking notes!  lol

It's still drilled into me.  The impedance of a capacitor at zero Hz is infinity.  The impedance of a capacitor at infinity Hz is zero.

What is it....  Impedance = 1/(j * omega * C) = - j/(omega * C)....  something like that?   Multiply by j/j.

Great show guys.

MileHigh

[picowatt]

Did it yesterday, 2800pF each side. Rgen=50 Ohm.

Works now, but the turn ON and OFF of the burst envelope are much slower, so I have to lengthen the run time.

.99,

It looks like you should also have about 140pF gate to drain and about 110pF drain to source if you want to try putting Coss in there (if it isn't already) to see how that performs.  The Coss components are involved in feedback. 

Coss is specified to =250pF
Coss=Cgd+Cds        5% of Ciss=Cgd=140pF,  Cds=250-140=110pF

PW

ADDED: It's a shame you can't model the voltage dependency of these capacitances.  Or can you?

As can be seen, once Vds falls below the knee in the graph .99 posted, Coss/Ciss change rapidly.  In particular, Coss changes rapidly with respect to Ciss.  During large signal swings that may drop Vds below the knee, these values modulate with signal and complicate AC analysis (particularly wrt feedback mechanisms).   If Vbatt is high enough (and/or signal swing low enough) to keep Vgs above the knee, it's a little less so.

[TinselKoala]

I hope Rosie Posie is taking notes!  lol

It's still drilled into me.  The impedance of a capacitor at zero Hz is infinity.  The impedance of a capacitor at infinity Hz is zero.

What is it....  Impedance = 1/(j * omega * C) = - j/(omega * C)....  something like that?   Multiply by j/j.

Great show guys.

MileHigh

Didn't you notice? At one point in my recent demo, the first Cap one I think, the bulb is _brighter_ when connected through the cap than it is when connected directly through the positive bus, with no changes to the FG setting, which is running at something around (secret frequency redacted).

Therefore.... free energy: the cap has _negative impedance_, sucking them zipons from the blogosphere of the Ainsliebrain to light a 3 Watt bulb to about the same brilliance as.... well, as the Ainsliebrain. Three Watts. Or three Joules rather, since 1 Watt = 1 Joule in the Ainsliebrain.

All I need is a million dollars to develop this negative impedance effect in poly caps into a commmercially viable product. Applications would include brighter car lights, faster microwave ovens, and even water pumps in the third world. I've patented the idea but allowed the patent to lapse so that everyone can know what a hero I am. But it's hard to find academics or replicators with the sufficient knowledge enough and picoqualtificiations and Etch-a-Sketch oscilloscopes who simultaneously are stupid enough to fish for that carp.