Two closely linked coils will double the inductance ; What will the addition of a third do? The third coil gets left out: The rule is ; Only two coils can couple and the two combined will out power any third coil. Now four coils can't beat the mutual inductance feature of two if you're halving the wire length. That would just be treading water. Any extra wire can just add to the two existing coils.


@Gotoluc,

Your choice of the highest perm toroid core rated in the Mhz range that you're operating in the a 55 Khz range, is not maximizing the full magnetic strength calculated by the permeability to inductance ratio formula. The core figure's out to have much more inductance strength on paper then it can deliver in magnetic field strength with the wrong frequency input!

"Magnetic permeability is not a constant figure, it changes with the frequency of the field".

__________________
 

Here's a 10 henry (Mega Coil) for $11. online: Imagine hooking an electro magnet and potentiometer up in series with a battery, and simply dialing the inductance from 10 henries down to near zero!

__________________
 

Measures 18.2 henry (Hy)
DC resistance of 135 ohms
Center diameter: 5/16"
Outer diameter: 1-1/8"
Height: 11/16"

$9.98 Ebay. This one has them all beat!

__________________
 

I just bought this 16 henry coil off ebay. Look at the stator at the core base for convienient electro-magnet placement:

__________________
 

One Tesla is the magnetic flux equivilant to a SI unit of one Henry. A Tesla is equal 10,000 gauss. It takes 700 Gauss to lift 3 pounds. Therefore to offset the 16 Henries we need almost 600 pounds of pulling force.

16 Henries is equal to one hundred sixty thousand Gauss. Luc's got four 1/2" x 1/8 N 35 discs. with around 2000 gauss. That's merely 20% of the close to one henry of inductance it's replacing at 10,000 gauss per Tesla and one Tesla equal one Henry of inductance.. The forces would equal each other if a D.C. current were applied instead of a low duty cycle pulse.

__________________
 

Tesla is an SI unit of flux density and is NOT equivalent to one Henry (which is a unit of inductance). One Tesla is equal to 10,000 Gauss, not 100,000 as Allen claims.

Do you ever check facts Allen?

__________________
 

@bistander,

Thanks for correcting me. I'm trying to do some ballpark math on the fly. You're right one tesla equals 10,000 gauss.

__________________
 

This 3" by 1-1/2" neo has 685 pounds of pulling force. This appears to be in proportion to offset the 16 henries of inductance!

Tolerances: ±0.004" x ±0.004"
Material: NdFeB, Grade N52
Plating/Coating: Ni-Cu-Ni (Nickel)
Magnetization Direction: Axial (Poles on Flat Ends)
Weight: 45.97 oz. (1303 g)
Pull Force, Case 1: 625.2 lbs
Pull Force, Case 2: 625.2 lbs
Surface Field: 5233 Gauss
Max Operating Temp: 176ºF (80ºC)
Brmax: 14,800 Gauss
BHmax: 52 MGOe


One Tesla is 10,000 gauss. 700 gauss can lift 3 pounds. One Henry of inductance can deliver one Tesla of magnetic flux. Therefore the 16 henries equals 160,000 gauss. Now, 160,000 gauss divided by 700 equals 228.571. Multiplied by 3 equals 685 pounds of pulling force exactly equal to the strength of the 3" x 1-1/2" neo disc. The rated neo disc gauss for the 3" disc is 14,800 very close to the 16,000 gauss we extrapolated with the rule of thumb factors.

Coupled with this electro magnet as a hildebrandt valve

•Product name : electromagnet solenoid; model : xrn-xp65x30
•Rated Voltage : DC 12V; lifting force : 80kg/176lb
•Overall Size : 65 x 30 mm / 2. 6" x 1. 2"(Dia. *T); thread DIA : 7mm
•Lead Length : 24cm/9. 5 inch
•Weight : 557G; package content : 1 x electromagnet solenoid

The last disc on the right has a pulling force of 115 pounds. This coupled with a 50 lb electromagnet would yield the kind of Inductance to magnet strength ratio Luc arrives at with his self running coil..

__________________
 

Posted again.

Your stated value of 160,000 Gauss is like 10 times stronger than the magnetic fields used in MRI.

__________________
 

@bistander,

A fully charged electro-magnet with 1 Henry of inductance, should generate 10,000 gauss of magnetic flux, with enough pulling strength to lift 42 Lb's off the floor. 160,000 gauss should lift 685 pounds, exactly as much as the most powerful N54 3" diameter x 1-1/2" neo disc pictured above. The Henry converts to the Weber/Ampere and converts to one Tesla of magnetic flux, and as you helped point out, 10,000 gauss.

16 Henries is a (Mega Coil). A fully charged electro-magnet with that much inductance could lift three grown men. Luc's pulsing with only a fraction of the full power. A magnet gauss to inductance ratio like Luc's would only need a few hundred pounds of pulling force; Still a very huge magnet compared to the tiny 1/2" N34 neo's Luc used.

I see your point though; When I work the coil inductance numbers through, it equals the pulling strength of the 3" neo magnet but the magnet's only rated at 10 times less gauss. 16,000 for the magnet and I have the coil gauged with 160,000. This has me very puzzled right now!

If the magnet were only 16,000 gauss, it should only have 68 pounds of pulling strength instead of 685, assuming 700 gauss can lift 3 pounds. The factor's only off by a power of 10! Hummm! There's a misplaced decimal somehow. Maybe you can help find the error in my math?

__________________
 

@bistander,

The most powerful junk yard magnet that lifts up cars generates one Tesla of field strength. I believe the equivalency was poorly stated between Henries of Inductance and Teslas of field strength. I think the Henry is good for 1000 gauss. This moves the decimal back where it belongs.

__________________
 

The 16 Henery coil should have 65 pounds of pulling force, not 650 at 16,000 gauss. That puts this $20. one inch by one inch neo tube below at 61 pounds:

You can see by the rating it's nearly 14,000 gauss:

Dimensions: 1" dia. x 1" thick
Tolerances: ±0.004" x ±0.004"
Material: NdFeB, Grade N42
Plating/Coating: Ni-Cu-Ni (Nickel)
Magnetization Direction: Axial (Poles on Flat Ends)
Weight: 3.41 oz. (96.5 g)
Pull Force, Case 1: 61.00 lbs
Pull Force, Case 2: 61.00 lbs
Surface Field: 5903 Gauss
Max Operating Temp: 176ºF (80ºC)
Brmax: 13,200 Gauss
BHmax: 42 MGOe

__________________
 

I recieved my inductance meter and attached both my 3/4" neo tube and my electromagnet to the laminated coil core of the 10 Henry coil and got the inductance to drop around 1/2 a Henry, down to 9 1/2 Henries.

I have an order of (12) 3/4" neo tubes arriving soon for my "Magnet Piston" and I'm going to need them all and maybe more, to lower the coil inductance to the level Gotoluc recommends for the self running coil. I'll upload a new video when I get some more meaningful results. The 10 Henry coil and electromagnet are pictured above in post 182. I ordered a 16 Henry coil and recieved a 10 Henry coil by mistake. The 16 Henry coil would have taken a massive neo magnet to reduce the inductance sufficiently, so it was perhaps a good thing they got mixed up.

__________________
 

Anyone who's followed my threads knows about my "Synchro Coil". A series connected bifilar coil measures twice the inductance of a single wire coil of the same wire gauge and copper weight, due to "Mutual Coupling". My prototype had several diametric neo tubes inside the solinoid core hole.

The reason I'm raising this is because the rest of the circuit was nearly identical to Gotoluc's self running coil. I'm changing course a little on my test bench to run some quick tests with my new inductance meter on the old kind of magnet coil.

I have only one 3/4 inch diametric tube. Everyone knows the diametric tube is polarized side to side. This, I found to be very important. The double inductance bifilar and the diametric tube, in a solinoid core supplied the capacitor with plenty of extra power at the correct frequency. I'm currently toying around with a 10 Henery coil that draws on a heavy laminated ferrite H core for a large share of it's inductance. It occured to me that my first setup was much easier to handle, because as it turns out, the ferrite core is really in the way. I'll get on it tomorrow.

__________________
 

A "Negative Micro Henry" is a unit of gain, and a measure of core saturation that has a Gauss equivalency. Running a ferrite rod into a solinoid coil core increases inductance measured in Henries. Running a magnet tube into a solinoid coil core, decreases inductance or increases "Negative Micro Henries". Ferrite cores have a permeability rating that has an inductance equivilant, and magnets have a Gauss rating that's convertible to the NMH.

This NMH factor is a relic of suppressed science that dates back to Joseph Henry, and it's practically impossible to find any kind of contemporary reference to the unit. Henry himself claimed it was a unit of gain. This is due to the coils electro-magnetic field that's added to the magnetic core field that trims the inductance.

Sliding a magnet into a coil core acts almost like pulling a ferrite core out. Rather then spacing magnets close to a ferrite coil core , simply sliding a "diametric" neo tube in and out of the core, as we do ferrite rods, should work as effectively to control "Negative Inductance". The value of the this kind of negative inductance is it's Gauss equivalency. Joseph Henry was probably able to generate power with this approach, just as Gotoluc and myself have, but that's not why he chose to categorize it as he did.

It's important to understand the difference between a "Negative Micro Henry" and no Henries at all, because an NMH has a magnetic field.

__________________
 

I just read that "Negative Henries" is capacitance. There is no such thing as "Inductive Capacitance"; A measure of the electrical charge an inductor can store should be evaluated in terms of inductance and magnetic field strength, not Farads and voltage.

These terms are not really technically inter-changeable, but are in common use. Dr. Dragone measured the electrical power stored in a permanent magnet by equaling the field strength with an electro-magnet and multiplying it's power consumption by the lifetime of the permanent magnet. The result is in megawatts of (Capacitence)?

Negative Henries have to be measured in units of magnet strength, not storage of electrical charge. It's very wrong and confusing for people to refer to NMH's in terms of electrical charge capacitance, and not Gauss Oersted's

__________________
 

I wound the bifilar, 6 milli henries exactly, and was surprised to not register even so much as 1 negative milli Henry when I inserted the powerful 3/4" diametric neo tube into the core. Inductance in the 4.8 Ohm bifilar, is exactly the same with the powerful magnet in the core as it is without it.

Negative micro Henries are apparently only available when a permeable ferrite core is present along with the magnet. The magnet alone won't produce any. However, this does not mean the powerful permanent magnet field penetrating the bifilar coil windings doesn't have an oscillating field generating potential. My earlier testing proves it does!

__________________
 

Art Porter's GAP coil generates a masking field. I believe that equaling the permanent magnet core strength with the electro-magnetic coil field sets the same condition up that Gotoluc matches by generating "Negative Micro Henries" in balance. I'm covering old ground here because I already generated power with P.M. coil field suppression and resurgence this way in my Dragone video to demonstrate the effect.

The power stored in the capacitor, read by the multi meter, is generated by the returning field of the permanent discs after being driven out by the electro-magnetic coil field. All it takes to balance the fields is to turn the D.C. power up on the coil untill the top disc magnet releases it's attraction:

https://www.youtube.com/watch?v=jBPKO9qSfGk

__________________
 

I'm set up to pulse the 10 henry coil; However I plan to first pulse my newly wound, 6mH diametric neo tube magnet core bifilar, with Gotoluc's circuit. The orange bobbin magnet core bifilar coil's pictured sitting on top of the 10 Henry coil below along with my new LCF meter to the right, capacitor diode, and PWM:

Attached Images

Magnet core coil..jpg (196.8 KB, 14 views)

__________________