Effects of perm. magnets on bifilar toroid transformer output

[void109]

Hi all.  I've been doing a lot of experiments in The Lab(tm).  I haven't posted any videos, as after making my inductance video showing increased inductance with presence of permanent magnet, my video camera failed.  Unfortunately I haven't learned enough about electronics to troubleshoot and repair it

I've stumbled on too many things that are interesting to not start posting them - so here's a series of pictures I took showing an effect I dont understand.  It looks brilliantly positive, however I'm old enough to know I likely just dont understand something obvious. 

It appears that simply adding the presence of a few neo magnets to this transformer DOUBLES its output without changing the input.  Hopefully some of you here can either tell me what I've done wrong, or suggest further details or experiments to validate/invalidate these findings.  I initially saw these results in a much more complicated setup I was doing while inspecting a previous idea for a magnetic flux gate generator, I did this to trim it down to the core of the matter.  Thanks in advance!

(btw much respect to JLN, just adding annotations and preparing images for upload is a big pain, much thanks for all of his hard work)

[void109]

The frequency isn't important to the effect, I can see it over a very large range of frequencies, I was just using trial and error to find the most voltage gain for the effect to make it as pronounced as possible.  If its important I can get scope shots of the freq gen output - its just a square wave output with a very small pulse width.

[gyulasun]

Hi,

For me it is not a 100% sure what is your exact circuit?

I mean:
1) you drive the primary coil directly by the generator output, via a series 1 Ohm resistor, right?
2) You load the secondary coil with a 1 Ohm resistor, this is ok.
3) what does the "input measured over the 1 Ohm resistor after 12V" mean? You measure the voltage drop across the 1 Ohm by the scope and the generator gives out 12V peak pulse voltage at 7.18kHz? Please clarify.
Or you mean on 12V a battery as seen in the photo, perhaps a binding point?

Yes, it would be good to see the input pulse, please make sure the scope zero line be clearly indicated, where it is with respect to the pulse waveform.

From what I can see so far, your core is saturated by the input pulse and when you add the magnets, then saturation changes to a "better" position on the core B-H magnetization curve (this is seen by the "nicer" output pulses versus the output "spikes-like waveforms" when no magnets added.

rgds,  Gyula

[void109]

1) 12V Pos Battery Terminal ==> 1 Ohm Resistor ==> Primary Coil ==> n-mos drain (Hope that makes sense)
2) Yes, the output from the secondary is just going to a 1 Ohm resistor, measuring across that with the probe
3) I mean that I'm measuring across the resistor identified in #1 above

I'll draw up the circuit tomorrow to post, as well as take better scope shots when I have time.

[MrMag]

You answered your own question in the first post. By adding the magnet you are changing the inductance. (Inductive Reactance)