I've spent a considerable amount of time working through how the Hubbard coil may work, and as per my opening post - even I have differing views ... lol
Having said that, I've worked out a combination that so far works. I believe all of the tubes are first wound with bucking coils. The primary tube's secondary is one coil in four parts, the output of which is fed to the output tube's primary bucking coil, which also has 4 coils as the output.
The first thing I came across was the fact, that when driving a primary bucking coil, V=IxR looks roughly right - 12V (105W) AC transformer, against an 8 ohm coil should see around 1.4-1.5A ... so far so good. Surrounded with 4 metal tubes with both ends capped with metal and that will drop to 700-800mA. Sweet!
Next is the fact that although you always take a current input hit inducing current into the secondaries, but with bucking coils, when you pass it to the output primaries, the input current is no longer working just in response to it's secondary. So the input required is again reduced when in the system.
Lastly, when a primary and output tube are wired right, the closer you bring the output to the primary, input current goes down and output volts/current goes up. They are working constructively.
This last bit explains where the massive amounts of current comes from. If you haven't put together two North ring magnets over a washer and been amazed at how much stronger the field is, then you need to. And if you have, imagine it being attracted to South ring magnets over a washer...an immense amount of flux.
I've just completed the fourth output tube, and with some pretty extensive testing, I've found out how the induction cycle works. Ironically, I now need to rewire it again - I have a habit of learning backwards.
So here is the breakdown:
Primary tube, wound with bucking coils, 4 layers, awg24, ~500+500 turns, ~8 ohm. The AC fed to drive this comes later (or earlier), but for now it makes an ok entry point.
Output tube primary is the device output. I'll be winding two layers of awg18.
The secondaries on the output are where the magic is. These are bucking coils, wired in the same way as the primary, and they are shorted. They act as a shield and a proxy for the primary tube magnetic field, decoupling the output coil from the primary. However the flux from the primary flows through the output tube and the shorted bucking coils relay the primary induction.
The shorted bucking coils are also used to induce the wire wrapping that goes around all of the output tubes, the output of which in turn drives the primary bucking coils.
Quite the balancing act. I'll report back when I've wound an output tube correctly....
Before getting too carried away, I've wound a layer of 1mm in two halves on an output tube. Over the top, I've wound half as two layers of 0.5mm, and half as one layer. Expectations have been met. Shorting either output primary across a meter costs me 5-8mA for an output of 350mA.
Unshorting the secondaries (shields) sees more current on output (again shorted over a meter), however the input current increase is near identical. The shields are up and working!
Hi Unimortal.
Thanks for sharing your experiments.
If measuring current with a DMM on 10A scale, the internal shunt can be considered the load. In this case, the 350mA is about 0.001 watts and the cost was 5 to 8 mA at 12v AC, or 0.06 watts, assuming a power factor of unity (which would not be the case.
I think some people here, possibly yourself included, consider that open circuit voltage and shorted current can be multiplied to give theoretical max power out but I admit that I don't understand why and that all my experiences tell me this is wrong. Having said that, I'm here to learn and I am often wrong!
Kind regards, Sandy
12-25-2025, 08:25 AM (This post was last modified: 12-25-2025, 08:54 AM by unimmortal.)
Revelations...
At the moment I'm stuck contemplating how to even explain what needs to be achieved. Powering the primary with AC is a good step forward, but spend too long there and you'll get misled.
The place to start is the outputs as the thinner wire won't take the 6-7 amps @ 48V to get started (guesstimate), and it will make more sense once you get you're head around the possibility that Hubbard didn't let the field collapse in the first place.
The backspike of quickly disconnecting DC (or AC) at the above inputs is going to be quite the spike...
So to support that I've now finished the output tube primaries:
21mm x165mm tube (plus thread for 200mm)
160 turns of awg18 (1mm) per layer
2 layers per tube - approx 20 metres
~1.1 ohm per tube
~2.4mH per tube
8 tubes in series, 2560 turns total...yeah, it's a big f'ing electromagnet
The shorted bucking coils wrapped over the primaries are where the magic is at. Wired as AC, with both outside coil leads going to one wire and a centre tap between the bucking coils going to the other wire, you can create pressure or vacuum. Pressure when you pressing from the outside, or vacuum when you press from the middle - like charges will repel away from each other when passed in at the centre tap.
It's this pressure/vacuum oscillation occurring that we need to tap at the right resonant frequency to reduce the magnetic resistance to zero between the output tube and the primary tube. To do this, Hubbard wrapped a winding (tertiary) around the outside of all the bucking coils, which just happens to be 180° from the primary. The bucking coils are then also reacting to just one side (the outside) of the coil as it tries to equalise, but on the other side there is a magnetic bias happening in close proximity to the primary tube, due to the nature of the bucking coils.
So in short we need to balance magnetic resonance and electrical resonance from either side of each output coil as the magnetic field within the output coils attempts to shrink, thus giving each output the ability to sustain without resistance.
I'm pretty sure of all of this, but the next steps still have me pondering.
... and I need a larger tube for the primary, so the outputs are further away from each other.
Edit: the outer tertiary layer is connected to the primary tube primary - that's the balancing act right there. The primary is wound in the opposite direction to the outputs, so when energised, there will be magnetic attraction between the the primary tube and output tubes.
