Self running coil?

[mscoffman]

Does this have anything to do with parametric resonance?  If not, then could parametric resonance be beneficial to this system.

Parametric resonance occurs in a system when a it is parametrically excited and oscillates at one of its resonant frequencies.  Parametric resonance takes place when the external excitation frequency equals to twice the natural frequency of the system. Parametric excitation differs from forcing since the action appears as a time varying modification on a system parameter.

http://en.wikipedia.org/wiki/Parametric_resonance

Thanks,

GB

@gravityblock;

There may be some of that going on. Parameteric oscillation are
when some of the component values parmeters shift. For example
the change of mosfet gate or drain-source capacitance with voltage.
It is not just 1f, 2f harmonic systems that can engage in parameteric
oscillation. As pointed out in wiki; Varicap diodes intentionally can
do this change (use spec sheets, if you think this is desired). It looks
like toroid coils themselves would engage in this as the coil magnetic
field strength increses, their inductance would change.

I was pointing out that I didn't think it would be easy to
find changes in component values that would reduce the
current below 49ua easily because other then the mosfet
(a) all the signals are already sinewaves -with no energy
invested in higher frequencies and (b) the two different
frequencies are harmonically related like a musical
instrument.

:S:MarkSCoffman

[gotoluc]

FWI

I've copied this from the energetic forum so you can be updated as to what point I am at this time.

Luc

Hi luc,
First off, genious resonator!  Thanks for trying the cap.  Ive run some math to help maybe.  Im not sure what your inductance in the last test is but im assuming its 200mH.  If thats the case than with the 0.002uf capacitor, the resonant frequancy of the coil should be 7957 Hz.  I find it odd that the calculated frequency of your coil is so far off from the frequency that you have been using :thinking: I wonder if the coils special winding plays a role in that.  Either way this may suggest that the tuning can get better.  You should be able to tune the frequency by putting a potentiometer in series with your oscilating inductor or using a magnet to tune that core.  But i might be wrong, its such a new oscilator, im still trying to wrap my brain around it.   I have figured out where some of your losses have come from by adding the capacitor.  In the tank circuit you now have introduced a circulating current, this current is much larger than the current you are putting into the tank.  We can use ohms law to determin the current. 

V=10.94V rms
R=6.7 ohms (coil resistance)
I=V/R
I=10.94/6.7

I=1.63 amps

Your at a low enough frequency that we dont have to worry about skin effect but your 30 awg wire is not capable of pushing 1.63A.  Maximum amps for power transmission of 30 awg is 0.142A.  So your wasting energy in heat. We can easily correct that be changing the value of the voltage. We can use ohms law again to calculate the maximum voltage you can use in that particular setup.

I=0.142A
R=6.7(coil resistance)
V=IR
V=0.142(6.7)

V=0.95 volts

If you take a temperature reading of your current setup running off 12V you should find that the coil is heating up, and dont forget the capacitor too.  It must be able to withstand the amperage as well.  If it heats up you can use multiple caps in parallel of lesser value to add up to the desired capacitance and give a higher amp capability.  And all wires between coil and cap must be able to handle the power as well.  So if you are pushing your toroid over 0.95 volts, than you are wasting energy in heat.  Please correct me if i have something wrong here.

Hi Cody.

thanks for your interest and help also

The inductance of the toroid coil (with magnets and air gap) in test 13 video is around 26mH + - 1mH

As for the oscillation inductor connected between gate and source. After a full day of playing with this, it seems there is no need for a resistor and the resistance of the inductor does not seem to matter. It's all about Inductance

At this time I'm playing with the circuit and will give you the details of the toroid coils. I say coils because I wound a quick one layer toroid as the mosfet pulse inductor.

The mosfet is a 2SK2806-01
Battery voltage is 12.88vdc
Main Toroid is 6.95 Ohms DC
Its Inductance is 117mH (with magnets)
Pulse Toroid is 0.097 Ohms DC
Its Inductance is 19mH

So using the 2SK2806-01 mosfet which needs min. 2v to trigger the above Pulse inductor specs will do it as long as the input voltage is 12.88vdc and the the main pulse coil inductance is 117mH. The result of this combination will be a sine wave Resonance at 14KHz.

Lower the main coil inductance and you will need to also lower the pulse inductor and the result will be a higher Resonance frequency.

Maybe a formula could be established that one could just input mosfet minimum gate trigger voltage, main coil inductance and source voltage, then it would give you the pulse coil inductance needed and also tell you the resonating frequency. I think this would be possible.

There is no need for the pulse inductor coil to be a toroid. I used one to see if I can find any advantages and see if less resistance used less power. So far I can't see any advantages.

Cody, can you please look this over and recommend the best voltage and frequency I should be using and I could re-tune to see if I can find any advantages. So far the lowest I could get the current down just before the circuit stops pulsing because of not enough pulse voltage produced (at gate) is 30uA @ 12.88vdc. The frequency range I tested is 30KHz down to 14KHz and all are about the same 30uA results.

Thanks for your help and time.

Luc

ADDED

Link to MOSFET pdf:  http://www.skory.gylcomp.hu/alkatresz/2sk2806.pdf

[gotoluc]

Hi Rob,

Re on common mode choke: you are correct the winding technique Luc used for his toroidal coils is really the one as the so called common mode chokes are made BUT the big difference is the way how they are connected: Luc connected the two coils in series aiding i.e. the MUTUAL inductances of the two coils add to the sum of the individual inductances in series,  so that the resultant inductance is nearly the 4 times of a single coil, L_resultant=(L₁+L₂+2M where L1=L2=L in the equation (the two coils are assumed to have the same inductance which is nearly true and M is nearly L because in ring cores the coefficience of coupling is nearly 1 ).  (A useful link on this is here: http://www.daycounter.com/LabBook/Mutual-Inductance.phtml )

I hope this helps clarify your doubt above.

rgds,  Gyula

Hi Gyula,

I have some questions about this toroid winding and connection technique I found and originally used this same toroid on my ORBO replication. BTW, this toroid coil gave me the best results on the ORBO. More Inductance with less windings = Less Resistance and more winding space for extra layers.

Here are my questions:

1. wouldn't using a toroid and this winding technique not have a benefit in a electric motor?

2. does more Inductance not give a stronger magnetic field?

3. does more Inductance cost more energy than a lower Inductance coil?

Always grateful for your help

Luc

[gyulasun]

Hi Gyula,

I have some questions about this toroid winding and connection technique I found and originally used this same toroid on my ORBO replication. BTW, this toroid coil gave me the best results on the ORBO. More Inductance with less windings = Less Resistance and more winding space for extra layers.

Here are my questions:

1. wouldn't using a toroid and this winding technique not have a benefit in a electric motor?

2. does more Inductance not give a stronger magnetic field?

3. does more Inductance cost more energy than a lower Inductance coil?

Always grateful for your help

Luc

Hi Luc,

1) it depends what you mean on electric motor, sorry.  in conventional motors a toroid with its closed magnetic path is normally not considered but if an inventor finds ways for applying it in a novel way: in ORBO the toroidal coil is used for 'shielding' the core from a magnet by way of saturation, as so far it is found

2) yes, more inductance gives a stronger magnetic field

3) it is a complex question, I do not know a strait yes or no but maybe it does.    The time constant L/R increases for sure, this means higher inductive impedance to resist current and if you want a quicker current response you have to increase input voltage to force higher current --> this involves higher input power.
MAybe other members here could comment some more on these.

rgds,  Gyula

[gotoluc]

Hi Luc,

1) it depends what you mean on electric motor, sorry.  in conventional motors a toroid with its closed magnetic path is normally not considered but if an inventor finds ways for applying it in a novel way: in ORBO the toroidal coil is used for 'shielding' the core from a magnet by way of saturation, as so far it is found

2) yes, more inductance gives a stronger magnetic field

3) it is a complex question, I do not know a strait yes or no but maybe it does.    The time constant L/R increases for sure, this means higher inductive impedance to resist current and if you want a quicker current response you have to increase input voltage to force higher current --> this involves higher input power.
MAybe other members here could comment some more on these.

rgds,  Gyula

Thanks Gyula for the quick reply.

Yes, the ORBO is a motor design that can use a toroid and I have other ideas how a motor could use a toroid but I need to know about the questions I asked to see if there is an advantage.

So you say yes to more inductance = a more powerful magnet field.

But you say more inductance may cost more energy. Is this because it usually takes more windings to get more inductance which = more wire resistance which = loss of energy?

Thanks for your help

Luc