When you look at Stan's schematics it is very, very vague as to the arrangements of the toroids so I decided to try some new ideas. I came up with a double toroid idea and immediately built one.
The one I built is not a good build as in the picture but I just wanted to test a few parameters.
The idea was to get the source impedance and the load impedance running in the same flux direction in both toroids as apposed to Thane Heins's design where he has flux running in all kinds of directions.
The general idea was to create one toroid that was much thinner and longer than the other toroid so it had an higher flux reluctance and the smaller toroid had a shorter route and a lower flux reluctance.
I made the toroid from one continuous length of wire which for every loop of the larger toroid, it formed three loop on the smaller toroid so that the smaller toroid has 21 loops and the larger toroid has 7 loops.
Now a word about this wire and wire toroids in general. A few years ago a University did a test on Silicon steel insulated wire cores and found that they were not efficient, in fact they had the same properties in losses as a laminated core made from mild steel. So wire is not the way to go and my core is even lossier because its not grained steel but normal steel.
My first test was to place a 500 turn 28 gauge primary on the larger toroid and take a few measurements and test it at various frequencies. The coil hated it between 10 and 20khz, got very hot and used about 1.5-2.0 amps. From 60hz to 1khz same results but it started to get happier going towards the 3 khz range.
Now when I pulsed the coil with 3.18khz it became more than happy, it didn't even get luke warm and when I looked at the amp meter I was quite supprised, only 10ma?
Next I did a flyback test on the coil while it was on the toroid, on an air flyback test this coil was around 1200v but on the core it was 600v which was quite inderstandable with a core that is basically a light bulb being inefficient as it is.
600v using the core as a load at 10ma somehow doesn't seem right though and its not getting warm? Has the coil become self resonant? Is that the reason is refuses to get warm and use any power?
A coil of this size should be self resonant in the Mhz, has this toroid arrangement made it resonant at a lower frequency? Absolutely no idea myself.
Anyway, did a few more tests. I wound a secondary around the area where both toroids cross of 200 turns of 28 gauge and half rectified the output. Only 50mv dc coming out of the secondary which I can understand because all of the 600v is stolen by the inefficient core, however the frequency at which the primary was happy changed from 3.18khz to 2.5khz. Still was using 10ma though and no heat at all.
Next test is to build the system again with a laminated silicon steel core to see if I can get most of the 1200v into a secondary of many windings probably double the primary and then have that outputted into a bifilar wound coil opposite the secondary on the smaller fatter toroid. The idea then would be to reflect the load impedance of the secondary into the bifilar coil and vice versa. The idea generally is to keep both of those load impedance's away from the primary but in the same direction on their respective flux path.
The one I built is not a good build as in the picture but I just wanted to test a few parameters.
The idea was to get the source impedance and the load impedance running in the same flux direction in both toroids as apposed to Thane Heins's design where he has flux running in all kinds of directions.
The general idea was to create one toroid that was much thinner and longer than the other toroid so it had an higher flux reluctance and the smaller toroid had a shorter route and a lower flux reluctance.
I made the toroid from one continuous length of wire which for every loop of the larger toroid, it formed three loop on the smaller toroid so that the smaller toroid has 21 loops and the larger toroid has 7 loops.
Now a word about this wire and wire toroids in general. A few years ago a University did a test on Silicon steel insulated wire cores and found that they were not efficient, in fact they had the same properties in losses as a laminated core made from mild steel. So wire is not the way to go and my core is even lossier because its not grained steel but normal steel.
My first test was to place a 500 turn 28 gauge primary on the larger toroid and take a few measurements and test it at various frequencies. The coil hated it between 10 and 20khz, got very hot and used about 1.5-2.0 amps. From 60hz to 1khz same results but it started to get happier going towards the 3 khz range.
Now when I pulsed the coil with 3.18khz it became more than happy, it didn't even get luke warm and when I looked at the amp meter I was quite supprised, only 10ma?
Next I did a flyback test on the coil while it was on the toroid, on an air flyback test this coil was around 1200v but on the core it was 600v which was quite inderstandable with a core that is basically a light bulb being inefficient as it is.
600v using the core as a load at 10ma somehow doesn't seem right though and its not getting warm? Has the coil become self resonant? Is that the reason is refuses to get warm and use any power?
A coil of this size should be self resonant in the Mhz, has this toroid arrangement made it resonant at a lower frequency? Absolutely no idea myself.
Anyway, did a few more tests. I wound a secondary around the area where both toroids cross of 200 turns of 28 gauge and half rectified the output. Only 50mv dc coming out of the secondary which I can understand because all of the 600v is stolen by the inefficient core, however the frequency at which the primary was happy changed from 3.18khz to 2.5khz. Still was using 10ma though and no heat at all.
Next test is to build the system again with a laminated silicon steel core to see if I can get most of the 1200v into a secondary of many windings probably double the primary and then have that outputted into a bifilar wound coil opposite the secondary on the smaller fatter toroid. The idea then would be to reflect the load impedance of the secondary into the bifilar coil and vice versa. The idea generally is to keep both of those load impedance's away from the primary but in the same direction on their respective flux path.