Reactive power - Reactive Generator research from GotoLuc - discussion thread

[itsu]

This is briefly the tuning process, if you have questions please ask.

Gyula

Hi Gyula,

i followed your instructions, but i do not see a clear point where the right bulb starts to decrease while getting both coils closer together.
Still the left bulb is showing an increase in voltage (not visible anymore in the bulb itself because of the moved cores to the outside).

I have 7 cores in each coil, measuring 9.33mH each, see end of the video.

Video here: http://www.youtube.com/watch?v=gIOWQntycJA&feature=youtu.be

Regards Itsu

[gyulasun]

Hi Gyula,

i followed your instructions, but i do not see a clear point where the right bulb starts to decrease while getting both coils closer together.
Still the left bulb is showing an increase in voltage (not visible anymore in the bulb itself because of the moved cores to the outside).

I have 7 cores in each coil, measuring 9.33mH each, see end of the video.

Video here: http://www.youtube.com/watch?v=gIOWQntycJA&feature=youtu.be

Regards Itsu

Hi Itsu,

Unfortunately, the dip at the original resonant frequency is small,  this means the change in the brightness can only be also very small and hard to notice by the eye, perhaps by monitoring the AC voltage by an analog voltage meter and not relying on the bulb brightness could help notice the dip by watching the needle.  Here is a dip in the center frequency of an overcoupled, mutually coupled two LC tanks: http://www.crystal-radio.eu/koppelinghoog.jpg

However, in your video I noticed the double peak behaviour which indicates overcoupling: I mean the blue trace which shows the voltage across the left hand side bulb, in video time between 3:02 and 3:10 or so the blue trace shows two peaks as you sweep the frequency in one direction, (I assume you did either upwards or downwards and you did not do it suddenly backwards just after an upwards peak).  And because of the coils are very close in that situation, please increase the distance between the coils and watch the blue trace when the two peaks disappear in the function of the separation, at a certain distance there should be only one peak remain in the blue trace (and not two) at the resonant frequency when you slowly sweep the generator. 
Sorry for this,  and I said the 5cm at random of course, coupling depends on several factors.

rgds,  Gyula

[itsu]

so the blue trace shows two peaks as you sweep the frequency in one direction, (I assume you did either upwards or downwards and you did not do it suddenly backwards just after an upwards peak).

Correct.

please increase the distance between the coils and watch the blue trace when the two peaks disappear in the function of the separation, at a certain distance there should be only one peak remain in the blue trace (and not two) at the resonant frequency when you slowly sweep the generator. 

I did that lateron when moving away the both coils untill the blue line was flat.
However as i mentioned then, there is no light in the right bulb then, so i probably have the correct coupling distance, but the
coupling power is not enough to light the bulb which makes it in this case somewhat useless.

Anyway,  i get the picture, thanks.

Regards itsu

[JulienVictor]

Dear

I am a highschool student and surely don't have that much knowledge as most of here have.
I have seen a video where gotoluc shows how he uses capacitors for having an overunity transformer, I drawed a picture of how I explain it simplfied, is this correct?

Kind regards, Julien

[gyulasun]

Correct.

I did that lateron when moving away the both coils untill the blue line was flat.
However as i mentioned then, there is no light in the right bulb then, so i probably have the correct coupling distance, but the
coupling power is not enough to light the bulb which makes it in this case somewhat useless.

Anyway,  i get the picture, thanks.

Regards itsu

Hi Itsu,

Well, I believe the inherent difficulty in this setup is the use of incandescent bulbs to indicate the tuning process and the power relations...  While the bulbs are spectacular indicators and were introduced in the original video,  the tuning process which is problematic in itself (due to the mutual coupling) is further complicated by the nonlinearly changing bulb resistance as the strength of the current changes:  when the filament is cold or only hardly glow (when the input frequency is coming near to the resonance but not yet spot on), the filament resistance is low,  this is 'good' for input side on the left because input current is not influenced too much.  And the low resistance at right hand side is also good because it does not ruin too much the Q quality factor of the right hand side (series) L2C2 circuit, selectivity is preserved there.
Nearing to resonance and reaching it with the generator, the right hand side bulb's resistance increases to a maximum as it brightens up (this resistance increase is true for the input bulb too but its current is still low due to the resonant impedance of the input parallel L1C1 circuit) and at resonance the Q of the L2C2 circuit gets much reduced because the filament already has its higher value hot resistance in series with L2C2, so the resonant current in L2C2 is limited by the increased bulb resistance.
The best would be to use fix resistors of a few Ohms (say 1 to 5 Ohm) instead of the bulbs and watch current drops across them by the scope. Even so, very careful adjustments  are needed to get the most power out by inductive resonant coupling.

Thanks for all your efforts!

rgds, Gyula