So I'm just wondering cuz it works as physical circuit but output in Ltspice is just a flatline on like 800mv?

Also I know air core xfmr doesn't have anywhere near unity coupling coefficient but I'm sure that's not problem with simulation! So thanks in advance if u can help

 

PS also I'm starting PSU at 0V cuz I know some oscillator simulations are fussy abt that!

 

The value of R2 seems a little high.

Post your .asc file.

 

The value of R2 seems a little high.

Post your .asc file.

Crutschow R2 is just arbitrary high impedance load to try and make simulator happy by closing secondary circuit! So the real oscillator runs w/o any connection to top of secondary at all

So fwiw HP was saying feedback is cuz of parasitic capacitance between upper part of secondary and Gnd giving secondary something to work against. But I don't know how to simulate that and she insists on making homework exercise out of everything cuz I'm like a perpetual kid in her eyes! But that's her bid not mine so tnx for reading post and whatever help you can give!

Crutschow I'll try to upload schematic file but I'm having problems with connection as usual So tnx anyhow and I'll keep trying!

 

Post your .asc file.

Crutschow I'll try to upload schematic file but I'm having problems with connection as usual So tnx anyhow and I'll keep trying!

Success!

 

So I just substituted a small capacitance C1, for R2 to simulate the parasitic capacitance you mentioned.

 

Cruchow tnx! Cuz I never thought to just add lumped capacitance to end of secondary! I was trying to think of way to have capacitance continuous along length of coil so I was over-complicating it

So anyhow now I'm playing with simulation and smaller cap gives higher voltage which I say is more to do with higher freq than just less loading cuz XC is tuned out at resonance anyhow So I'm happy that Ltspice is more fun now that I'm getting feel for it!

 

See

 

I beg your pardon. The third inductance has no magnetic coupling.

 

I just took crutschow's first bit of advice and changed R2 to 22k.Works fine.

 

I just took crutschow's first bit of advice and changed R2 to 22k.Works fine.

Indeed! What @Aleph(0) was 'missing' was the fact that even an 'open' secondary is capacitively loaded - and, considering the frequencies involved, to significantly lower impedance than 10MΩ

Best regards
HP

 

Cruchow tnx! Cuz I never thought to just add lumped capacitance to end of secondary! I was trying to think of way to have capacitance continuous along length of coil so I was over-complicating it

So anyhow now I'm playing with simulation and smaller cap gives higher voltage which I say is more to do with higher freq than just less loading cuz XC is tuned out at resonance anyhow So I'm happy that Ltspice is more fun now that I'm getting feel for it!

Further to that, please be advised that much of the 'demonstration phenomena' (i.e. brilliant illumination of linear florescent lamps, etc) owe far more to the circuit's relatively high operating frequency than to its (decidedly modest) output EMF (With attention to the former's role in 'enhanced' electrostatic coupling, radiation/transmission line effects, etc...)

Very best regards
HP

 

View attachment 129646

Indeed! Placement of a diode across the b-e junction is essential to even the most basic design!

Best regards
HP

 

and she insists on making homework exercise out of everything cuz I'm like a perpetual kid in her eyes!

Heaven forbid I dare you to think! -- Shall I take 20 lines?

TTFN
HP

 

Heaven forbid I dare you to think! -- Shall I take 20 lines?

TTFN
HP

Thinking is highly overrated and should be discouraged at any level of growth.