Proof of concept - perturbing a static magnetic field

[z_p_e]

Having duplicated Otto&Jason's driver/mosfet combination I've now got a much better setup. The main difference other that using a low side driver and not the high side driver, is the addition of two decoupling capacitors directly across the power inputs to the driver. This removed much of the rubbish and I was getting much crisper square waves when entering high khz 500K+.

I've also noticed that when applying a larger 24V across the coil to generate the static magnetic field, that the ability of one coil to induce into another coil is cut in half, REGARDLESS of the direction of current applied to generate the static magnetic field. In other words it doesn't matter whether N is top of the coil or bottom of the coil, they both have the effect of reducing the coupling between the two inducing bifilar coils.

I expected this to happen in one direction, but thought that in the other direction there would be an enhancement.

Bob,

If you are using a ferromagnetic core, perhaps it was being saturated with the static field applied, and not without it. This would explain the reduced coupling.

Darren

[brnbrade]

Hello all

This morning I played with resonant frequencies of my walkman in the ring tpu that I built.
I input whit 2 cells 1.5v, and collect 52v 1A in output.
When I decided to put a permanent magnetic ring in turn of the rings collectors and...
Amaze, the readings jumped for more than 250v. with two cell my reader was crazy.

I hope help

Regards

[chrisC]

@brnbrade

Great! Can you tell us a little bit more of your setup, circuit, current measurements and ring structure please? There is not enough information from your post to understand what we are supposed to understand? Thank you.

Regards
chrisC

[brnbrade]

@brnbrade

Great! Can you tell us a little bit more of your setup, circuit, current measurements and ring structure please? There is not enough information from your post to understand what we are supposed to understand? Thank you.

Regards
chrisC

Hi ChrisC
My TPU comprise in 24 turns medium wire  and 1000 turns more fine wire in parallel, mounted in pvc tube and isolated well isolated. I put permanent magneto ring in turn of the tpu and reader  jumped as crazy above the 250v.

TKS

[chrisC]

Hi brnbrade:

Thanks for the reply. What was your input frequency (assuming only one?) into the primary and was there analog ammeters measuring the currents in the primary and secondary? A photo or graphics image of the circuit would really be appreciated if that was not too much trouble for you.

Thanks

chrisC