0:30 / 6:17 Internal energy release of ferromagnetic resonance materials

[Sandy]

Hi Sandy, just now I noticed that you have a power resistor connected in front of your capacitors, is this to limit the current? So that might be the reason I coudn't get the effect.
Can you please tell me the resistor value, so that I try to replicate your setup exactly?

Thx again,

Dann

Hi Dann.
Resistor is current shunt 1 ohm for scope trace. Does not effect operation.
Kind regards, Sandy

[kloakez]

Hello everyone,

can someone recommend me transformer that I can use for ferroresonance? Some 220V to 12V would be preferable. Or does it not matter that much which transformer I use to get ferroresonance and I can try any that I can get? I am also planning to use it with an autotransformer, to control input voltage, so I guess 220V to 110V transformers would do too.

What is the rotoverter or transverter supposed to do? (except sounding awesome in australian accent) I have been looking at the schematic for some time and I think it could be getting the transformer into ferroresonance. If it was going into and out of ferroresonance, that would be modulating the inductance of the transformer, which would make what is called parametric resonance, which could totally be a gain mechanism. I just never used a rectifier this way so I am not sure what it does the "other way".

[Sandy]

Hello everyone,

can someone recommend me transformer that I can use for ferroresonance? Some 220V to 12V would be preferable. Or does it not matter that much which transformer I use to get ferroresonance and I can try any that I can get? I am also planning to use it with an autotransformer, to control input voltage, so I guess 220V to 110V transformers would do too.

What is the rotoverter or transverter supposed to do? (except sounding awesome in australian accent) I have been looking at the schematic for some time and I think it could be getting the transformer into ferroresonance. If it was going into and out of ferroresonance, that would be modulating the inductance of the transformer, which would make what is called parametric resonance, which could totally be a gain mechanism. I just never used a rectifier this way so I am not sure what it does the "other way".

I don't know much but if I were to start fresh I would use very small transformer for saturation at lowest possible power for first experiments. Unfortunately this will have low Q so not good efficency but easier to see effect of ferroresonance. I think your idea about the operating principle may be correct. This is all my opinion not solid knowledge. 
Kind regards, Sandy

[kapierenundkopieren]

Hello kloakez, like Sandy said, start small, this means with a transformer smaller than 50VA, it can be any kind of step down transformer (less voltage on secondary means safer to handle).
For the capacitor you can start at 0.5uF (use caps in series for greater voltages) and without a load, just spark the secondary and see if there is change in sound and voltages on primary and secondary.
When the ferroresonance kicks in make sure you dont leave it on for too long or it will fry your transformer (see how fast it heats up).
Be extra carefull if you connect directly to the grid, the effect will be much greater - the other day I tried this with a 50VA transformer and 1uF cap, and the voltage on the primary was 600V+ RMS, so also be carefull to not fry your multimeter or scope (I use probes X100 for this).
Also an adequate circuit breaker directly from your grid socket is a must.

Good luck,

Dann

[kloakez]

Thank you Sandy and Dann. I am only missing the transformer to try the ferroresonance and ferroresonance with a transverter. I guess I will order some and when it arrives, I'll try it out. I will be using a VARIAC with a fuse on the mains side, that should be safe enough I hope Guests cannot see images in the messages. Please register at the forum by clicking here to see images.

[stranger]

Hello,

I am new here. I though a little bit of theory would be useful.
If you know VA curve of your transformer it is easier to guess what input voltage is required to get it into ferroresonace state.

Have fun,
Alexey Guests cannot see images in the messages. Please register at the forum by clicking here to see images. 


  fr.pdf (Size: 295.14 KB / Downloads: 25)

[stranger]

   

I made many experiments before with ferroresonance, but it never came to my mind to connect load in parallel to the coil. Quite interesting results.

   

Here how it looks

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[Sandy]

I made many experiments before with ferroresonance, but it never came to my mind to connect load in parallel to the coil. Quite interesting results.



Here how it looks

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Hi Alexey. Thanks for sharing the pdf and the photos of your experiments. Nice result. Are you sure you had ferroresonance not LC resonance? Looks like your series LC circuit resonant frequency would be 50hz but you operating at 71Hz (parallel load pulled inductance lower?) Did you have to do anything other than turn on power to get it resonating? Primary input waveforms look like classic LC resonance waveform.


I struggled to replicate the HOLDER demonstration but evrntually succeeded with a different transformer. Ran out of time and did not connect oscilloscope. Circuit pulls a lot of current from source and efficency is terrible but it was good food for thought regarding schematics you showed previously.


]Are these circuits just series LC resonant circuits and the saturation lowers inductance to meet the capacitor value for the given frequency?[/size]
[size=1]Has anyone here achieved the ferroresonance without the series cap?

During session today, before I found a transformer that would do it like HOLDER, I tried with different 15VA transformer which would give a slight burst of brightness in the load when the secondary was momentarily shorted. I took oscilloscope shot of a single event. Between arrows is on (secondary shorted) time. Yellow is load volts, blue is input current, pink is input voltage.

Kind Regards, Sandy

[stranger]

I made many experiments before with ferroresonance, but it never came to my mind to connect load in parallel to the coil. Quite interesting results.


Here how it looks

Guests cannot see images in the messages. Please register at the forum by clicking here to see images.

Hi Alexey. Thanks for sharing the pdf and the photos of your experiments. Nice result. Are you sure you had ferroresonance not LC resonance? Looks like your series LC circuit resonant frequency would be 50hz but you operating at 71Hz (parallel load pulled inductance lower?) Did you have to do anything other than turn on power to get it resonating? Primary input waveforms look like classic LC resonance waveform.
I struggled to replicate the HOLDER demonstration but evrntually succeeded with a different transformer. Ran out of time and did not connect oscilloscope. Circuit pulls a lot of current from source and efficency is terrible but it was good food for thought regarding schematics you showed previously.
 
Are these circuits just series LC resonant circuits and the saturation lowers inductance to meet the capacitor value for the given frequency?
Has anyone here achieved the ferroresonance without the series cap?

During session today, before I found a transformer that would do it like HOLDER, I tried with different 15VA transformer which would give a slight burst of brightness in the load when the secondary was momentarily shorted. I took oscilloscope shot of a single event. Between arrows is on (secondary shorted) time. Yellow is load volts, blue is input current, pink is input voltage.

Kind Regards, Sandy

Hi Sandy,

when core starts saturating you see that current become more like triangle and voltage closer to rectangular
(see picture)

   

If you continue increasing input voltage then oscillations became more chaotic (similar to what you show on the picture).

Usually I tune LC resonance on very low power and then just increase input power.

My understanding is that LC resonance helps increase voltage and current in the circuit and make easier to achieve core's non-linearity. Without capacitor you can have non-linear scope traces but there will be no resonance. See fr.pdf I shared earlier, there is good explanation how negative resistance occurs.

I measured inductance and calculated needed capacitor value for 50hz, but then it appeared that maximum amplitude is at 71hz, my L meter not very good for large coils.

Regards,
Alexey



PS something wrong with text formatting, can't see your message properly at the beginning

[Jim Mac]

PS something wrong with text formatting, can't see your message properly at the beginning

It looks like the text was copied from somewhere that brought along size formatting..  I edited the post and removed the formatting fragments.