Reactive power - Reactive Generator research from GotoLuc - discussion thread

[penno64]

Was thinking exactly the same thing. Aussie gear.

Penno

[gotoluc]

Interesting Luc.

There are a number of things going on that are affecting the scope measurement. Also note that most of the power from the FG is being wasted inside the FG's 50 Ohm output resistor.

If you look at the wave forms when the circuit is connected, you will notice that the math trace indicates almost as much negative power as positive power. You judge this by estimating the area inside the trace. It comes down to comparing the area inside the positive triangular shape vs. the area inside the long/shallow negative shape. They seem pretty close, but I would guess judging by eye (not always a reliable method) that the positive area is larger. A good indicator if you are searching for OU.

Another way you can try to see what the net MEAN is, is to adjust the time (horizontal axis) so that precisely one cycle is displayed on the screen. You may have to go out of horizontal cal for this. Then see what the math mean indicates.

The "modulation" you are seeing can be due to one of two things, or even both; 1) Moire patterns and 2) undersampling in the scope. The fact that the mean varies so much as you change the time base settings is cause for concern. When those math peaks appear and disappear, or seem to jump up and down in amplitude, that is usually the result of undersampling. The longer you make the time base setting to display more cycles, the worse the problem becomes. If the scope has a relatively short or small memory depth then these problems can rear their ugly heads.

Thanks for the reply and information poynt

I was doing like you say (looking at the surface area of consumption and return) and why I started the video that way so you could see how close they are.

I'll try it with one cycle to see what the math comes up with but I think I did try that already and the math mean wasn't stable.
I think you're right,  there must be a sampling limit and that's why the data changes so much.

I was testing the toroid today with 12vdc pulses and collected the flyback to another 12vdc battery using my best Shottkey diode.
At 650Hz with 10% duty cycles I was able to collect back around 95% of the energy after dc rectification. I didn't bother calculating the LED power, which I don't think is much, as you know these LED's make a good show with short pulses in the 1khz with next to no power.

After spending the day doing tests I've concluded it's under unity but one of my better power return scores.

Thanks for your reply

Luc

[verpies]

I think one point that should not be overlooked is that when Itsu tuned it to full resonance the bulb in the primary glowed a bit, showing more input at full resonance than when just off a fraction.

That is because the system is not tuned precisely under load.
 
Itsu is using two identical caps and loosely coupled coils but the current flowing in the secondary winding under load, effectively DECREASES the inductance of the primary winding (due to Lenz law, reflected impedance, etc...)

If Itsu had searched for the precise primary LC resonance frequency (f_P) under load  - while the secondary winding was connected only to the output bulb (no cap), then he would find that f_P is higher with a loaded secondary winding than with an unloaded or open secondary winding.

Finally, if he tuned* the secondary LC tank's resonance frequency (f_S) to be equal to the primary resonance frequency (f_P) under load, according to the procedure just outlined above, then the whole system would behave more perfectly (like in the first video).


P.S.
* e.g.: by decreasing the series capacitance in the secondary LC tank.

[itsu]

By the way Itsu how did you get an Oscilloscope with "Australian Defence Force" written on it ? 

Cheers

Simple:

http://www.ebay.com/itm/Tektronix-TDS3054B-Digital-Phosphor-Oscilloscope-/321215388314?pt=AU_B_I_Electrical_Test_Equipment&hash=item4ac9edda9a


Regards itsu

[itsu]

That is because the system is not tuned precisely under load.
 
Itsu is using two identical caps and loosely coupled coils but the current flowing in the secondary winding under load, effectively DECREASES the inductance of the primary winding (due to Lenz law, reflected impedance, etc...)

If Itsu had searched for the precise primary LC resonance frequency (f_P) under load  - while the secondary winding was connected only to the output bulb (no cap), then he would find that f_P is higher with a loaded secondary winding than with an unloaded or open secondary winding.

Finally, if he tuned* the secondary LC tank's resonance frequency (f_S) to be equal to the primary resonance frequency (f_P) under load, according to the procedure just outlined above, then the whole system would behave more perfectly (like in the first video).


P.S.
* e.g.: by decreasing the series capacitance in the secondary LC tank.

Thanks verpies,

my idea was that i had created an overcoupled bandpass filter, but i can have a go at your suggestion/solution.

Regards Itsu