Turning on and off a Pernament Magnet Field

[gyulasun]

Hi Romero,

I think the 'ultimate' setup would be which does not let out any magnetic flux from the permanent magnet when the coil is unpowered and it would add the flux both from the permanent and the electromagnet when the coil is powered, right?

IF this is the goal, then here is a drawing which seems to accomplish just that:
http://www.overunity.com/index.php?topic=4624.msg96814#msg96814

A permanent magnet is fully embedded in a soft iron core and a coil is wound onto the outside of this core.  When there is no current in the coil, the permanent magnet flux goes inside the core as shown in the upper drawing.  When the current is on, with the correct polarity, then the flux from both the coil and the permanent magnet is summed, this means a strong field appears axially on the left and right ends of the core, as shown in the lower drawing.

What do you think?

EDIT:  I think, even a soft iron piece of mumetal or transformer lamination would be worth considering, formed into a U shape to insert a magnet into it.

Gyula

[XS-NRG]

What do you think?

Gyula

I think like so:

[romerouk]

Hi Romero,

I think the 'ultimate' setup would be which does not let out any magnetic flux from the permanent magnet when the coil is unpowered and it would add the flux both from the permanent and the electromagnet when the coil is powered, right?

IF this is the goal, then here is a drawing which seems to accomplish just that:
http://www.overunity.com/index.php?topic=4624.msg96814#msg96814

A permanent magnet is fully embedded in a soft iron core and a coil is wound onto the outside of this core.  When there is no current in the coil, the permanent magnet flux goes inside the core as shown in the upper drawing.  When the current is on, with the correct polarity, then the flux from both the coil and the permanent magnet is summed, this means a strong field appears axially on the left and right ends of the core, as shown in the lower drawing.

What do you think?

EDIT:  I think, even a soft iron piece of mumetal or transformer lamination, formed into a U shape to insert a magnet into it.

Gyula

I think that if we use your suggested link we can get some simmilar effects but having poles connected thru the outside iron core most of the flux will be locked inside that core. In my setup we push the flux forward. I have been working all day to get the best performance for the minimum power applied to the L1 and L2 coils. Right now I am using 2 mumetal rods, 12mm diameter/6mm long.I have tried different number of turns, today I have 15 turns for each coil and I get best performance with 1.2volts/0.540ma input and  output 61v/0.192ma, 58.9kHz. The magnets used are 10mm diameter/5mm . I am going to order bigger mumetal rods then I can use bigger magnets hopping to get better performance.

[MasterPlaster]

This is how its done:
http://www.youtube.com/watch?v=Z_UHixEy7xU

[romerouk]

Below are some strange scope shots from the output of my device running at 59.2kHz