09-14-2024, 08:28 PM (This post was last modified: 09-14-2024, 08:34 PM by Sandy.
Edit Reason: Added some info i forget and grammatical correction
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Hi Alexey,
Thanks for answering.
Here is my latest. Please, what is your interpretation of the waveforms here? Am I correct in thinking that the average input power is close to 0? Ignore the voltages for now as I only have 1 functioning low voltage probe and used high voltage probe for yellow trace.
Also, thanks to admin for correcting formatting errors.
Kind regards, Sandy.
You have close to 90 degrees phase shift between voltage and current, your circuit tuned to resonance,
so most energy going back and forth between power supply and circuit.
You could say that power is 0 if waveform would be symmetrical, but there are small asymmetry (I marked with green color). So it is close to 0.
Regards,
Alexey
BTW current and voltage shapes are sine, it is not ferroresonance
09-15-2024, 05:24 AM (This post was last modified: 09-15-2024, 05:28 AM by Sandy.
Edit Reason: Added note
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(09-15-2024, 02:26 AM)stranger Wrote: Hi Sandy,
You have close to 90 degrees phase shift between voltage and current, your circuit tuned to resonance,
so most energy going back and forth between power supply and circuit.
You could say that power is 0 if waveform would be symmetrical, but there are small asymmetry (I marked with green color). So it is close to 0.
Regards,
Alexey
BTW current and voltage shapes are sine, it is not ferroresonance
Thanks. I'm sorry there is something wrong with my scope or new probes or user error. I was confused by these measurements and now I cannot get the channels in phase with a resistive load. Please ignore my last schematics and scope pictures.
Thanks,
Sandy
Edit...
High voltage probes were shifting phase measurements 90 degrees. Ha too good to be true. Is this a common occurrence?
(09-15-2024, 05:24 AM)Sandy Wrote: High voltage probes were shifting phase measurements 90 degrees. Ha too good to be true. Is this a common occurrence?
So far haven't seen this issue with HV probes, but it probably depends on model/construction/purpose of the probe
Here is data sheet on the ferrite material specifications used for them where such cores natural mechanical resonant frequency is mentioned in Page 3: https://elnamagnetics.com/wp-content/upl...cation.pdf
And a formula is given to calculate the resonant frequency of the core, depending on the mechanical sizes.
Philips was bought by Ferroxcube long ago and unfortunately Ferroxcube finished manufacturing the 3R1 material used for this ferrite core.
The way I understood the transcript, they say they want to bring the power factor up to 1 and even higher (wt?). Doesn't sound like COP 1 to me, rather COP 0. I remember I once followed a plan by that Kelly collection, involving a diode and a transformer. That transformer rattled like a bike engine and AFAIR a fuse blew. Basically preventing any current from flowing back, although just in one polarity. I'd assume any resonance at the input of an unloaded primary can mess up your power factor, which, without a load, would otherwise be ideal, or near zero. Current within the resonant echo may pose almost diode-like features for a current that flows in opposite direction in the same wire, like the reactive current that is out of phase.
Maybe worth trying to phase-shift the primary to PF 1 that way, so a load at the secondary will/may further shift it to 90 or 270 degrees. But then again, being fully in phase just means the coil has lost it's impedance and acts like a bifilar that's wired anti-parallel.
Well, TBH this isn't my field of expertise. But neither seemed these Chinese guys to know what they were elaborating about, unless they weren't after excess energy at all. Sure it's an interesting experiment. But was it about free energy at all?
according to a book on power supply design, cores should have specs on their resonance. and based on that spec the supply design should stay far below and even stay away from harmonics of the core resonance spec. all pretty much to say that the core ferro resonance will affect the workings of the supply design....
so if you want to experience ferro resonance, you will need to drive it at spec freq or a lower harmonic of that spec, not just high saturation of the core.
Here is another way to go about it. I threw this experiment together quickly. I am currently lacking power resistors and undamaged oscilloscope probes so I'm not making any claims here but for those of you who actually do experiment, this looks quite promising to me. If we drive our transformer with a load that slightly overpowers it, (17 watts on a 15 watt transformer, in the example shown here) then the pulse from the capacitor might drive the transformer into the negative resistance portion of the VA curve as described in Alexey's PDF. The good thing about doing it this way is that we are adding energy to the load to achieve the saturation, rather than taking it away. It would make a good experiment for those of you skilled in power electronics who already have HV high power H bridge IGBT switch modules at your disposal. Remember that if replacing the spark gap with a solid state switch, the switch should probably conduct in both directions to mimic the behaviour of the spark gap. Please understand that I am sharing my ideas and do not have a working device. Please use great caution with HV caps and spark gap!
09-23-2024, 04:34 AM (This post was last modified: 09-23-2024, 04:34 AM by Sandy.)
(09-22-2024, 06:57 PM)Sandy Wrote: Hi folks,
Here is another way to go about it. I threw this experiment together quickly. I am currently lacking power resistors and undamaged oscilloscope probes so I'm not making any claims here but for those of you who actually do experiment, this looks quite promising to me. If we drive our transformer with a load that slightly overpowers it, (17 watts on a 15 watt transformer, in the example shown here) then the pulse from the capacitor might drive the transformer into the negative resistance portion of the VA curve as described in Alexey's PDF. The good thing about doing it this way is that we are adding energy to the load to achieve the saturation, rather than taking it away. It would make a good experiment for those of you skilled in power electronics who already have HV high power H bridge IGBT switch modules at your disposal. Remember that if replacing the spark gap with a solid state switch, the switch should probably conduct in both directions to mimic the behaviour of the spark gap. Please understand that I am sharing my ideas and do not have a working device. Please use great caution with HV caps and spark gap!
Hi folks. I got new oscilloscope probes today and my results were very different and not worth pursuing. New probes do not show the big gain in amplitude across the load demonstrated in the video. I apologise!
Kind Regards, Sandy.
