Rosemary Ainslie Circuit Demonstration June 29, 2013 Video Segments

[TinselKoala]

Part 4ab of the continuing series "works mosfet how dat" Negative Bias explanation of the oscillations in Q2.

http://www.youtube.com/watch?v=kV2ePEbJ76I

[TinselKoala]

Part 4c: Radio NERD: RF power in the Ainslie Q2 circuit, and the common-gate oscillator as RF transmitter.

http://www.youtube.com/watch?v=H14qF_CLHp8

[profitis]

wait a minute wait a minute guys.it has come to my attention that the ainslie resister coil is made of nichrome.nichrome is capable of magnetic allignment thus i just want to put for the record that i may have been wrong to dismiss her circuit too quickly.apologies to her

[TinselKoala]

Does this mean you'll finally get off your butt and go over there and help the poor woman out? Good, because it's really clear that she needs all the help she can get, and the two of you deserve the best: each other.

Meanwhile..... I'll just keep on demonstrating what _really_ happens with "her" circuit. Got any questions about what you've seen so far?

Or are you even bothering to watch?

[TinselKoala]

Maybe profitis could explain Ohm's Law to her, for starters.

You have NOT yet told us what you're using by way of a shunt resistor.  From my perspective it seems that a shunt that can show such major variations to its Ohmage values is somewhat suspect as a reliable measure of anything at all.  And I would have thought that the measurements should be possible - optionally at ANY point on that CSR  including those 'test points'.  If these measurements vary - as they do on your set up - then the shunt is NOT non inductive.  Then.  You recommended that we retain the use of our own CSR type - but that we replace the 4 that we have with a 0.25 Ohm number.  I'm telling you again.  We have a wattage dissipated in excess of 50 watts.  It would be foolhardy to replace this with such a small resistor unless it also has a high wattage tolerance.  We have NOT found such a resistor.

No, Ainslie. You have a MAXIMUM current through your CVR of around 6 amps, even when you are using 6 batteries.
(A total circuit resistance of, say, 13 ohms and a 72 volt supply, if connected by simple wires, will give you a current of I = V / R, or 72/13 = around 5.4 Amps.)
The power dissipated by a resistor is given by Ohm's Law as P = I² R.  Your maximum current is 6 amps and the suggested shunt resistor is 0.25 Ohms.

DO THE MATH.

Oh.. that's right, you cannot. 6x6x0.25 = 9 Watts. There will be a MAXIMUM of 9 Watts dissipated in your "shunt" during a trial with a 72 volt supply. Typically your maximum current is much less.... as you demonstrated quite well on Saturday the 29th of June.

You have been given the part numbers of noninductive shunts that have plenty of power handling capacity and only cost six dollars and you can order them on the internet and have them in your fenced compound in four business days. You have no, zero, zip, zilch excuse for any of this whining and protestation.

http://www.ebay.com/itm/4ps-Caddock-MP816-0-25R-1-non-inductive-resistor-brand-new-/220855731235?pt=US_Amplifier_Parts_Components&hash=item336c070423