Mostly Permanent Magnet Motor with minimal Input Power

[gotoluc]

Hi Gyula,

the measured coil capacitance between strands is 59nf and each strand has 3.2mH with coil moved to center to 3.9mH with coil at end. DC resistance of each strand is 1.4 Ohms
Cannot measure series Inductance with my good meter and have no other meter that works

Luc

[Magluvin]

Yes must be because the input is a capacitive discharge compared to the previous test was continuous DC pull force test

I've also noticed the coil holds up a little longer when connected in series. Maybe it's the small coil capacitance? or maybe it's just the coil has more inductance so now the generator effect is more as the coil drops down with gravity and tries to charge the cap bank in opposite polarity?

Luc

Hey Luc

I agree with Gyula that most likely the resistance change would have a difference in drain time of the cap.  I would recommend a constant dc input, using caps to stiffen the supply, trying to maintain solid input to either coil for these tests. 

The effect of capacitance of the bifi increases with voltage increase. The higher the voltage, the acceptance of that voltage by the bifi gets better, overcoming the bifi inductance, as suggested in Teslas pat for electromagnets.  Would be interesting to see 100v - 500v cap discharge into each version of the coil. Just for the heck of it.

Gota do laundry. 

Mags

[gotoluc]

If you suspect the increased generator effect of the series coil configuration is also to blame for the little longer holding time then consider to include a diode in series with the capacitor with forward direction to the discharge process i.e. lifting, so it will block any reverse voltage hence current in the falling phase of the coils.

Gyula

Hi Gyula,

I did place a diode between my 7170uf electrolytic capacitor and the coil but all that does is charge the cap to an negative value when the coil starts to fall back down since the current is going in the opposite direction when it fall.
Cap starts at +10vdc and coil travels up 12.3mm then the cap goes Negative as the coil starts falling back down and cap charges to minus -6.72vdc

The cap being electrolytic don't hold the negative charge too well but only loose about 1vdc.

Make a recovery system though!

Maybe if I use AC caps it would be more efficient?

Luc

[gotoluc]

Hey Luc

I agree with Gyula that most likely the resistance change would have a difference in drain time of the cap.  I would recommend a constant dc input, using caps to stiffen the supply, trying to maintain solid input to either coil for these tests. 

The effect of capacitance of the bifi increases with voltage increase. The higher the voltage, the acceptance of that voltage by the bifi gets better, overcoming the bifi inductance, as suggested in Teslas pat for electromagnets.  Would be interesting to see 100v - 500v cap discharge into each version of the coil. Just for the heck of it.

Gota do laundry. 

Mags

Hi Mags

I think I understand what the benefit of "overcoming the bifi inductance" would be but if you don't mind I would like to get your version of the benefit... once you have time between loads that is

Luc

[Magluvin]

Hi Mags

I think I understand what the benefit of "overcoming the bifi inductance" would be but if you don't mind I would like to get your version of the benefit... once you have time between loads that is

Luc

Just loaded up and headed out to do laundry.

Instead of the slow rise in current due to self inductance of the coil when input is suddenly introduced,  the capacitance draws in the charge of higher voltages faster than lower voltages, producing more prominent impulse rather than slow rise to current peak of a normal wound coil/inductor.

Try a smaller cap at a higher voltage and redo the tests. Unless you have large caps that can handle 100 or more volts. Just for giggles. Into the 1000s of volts, the effect should be more prominent.

Ive been looking at litz wire so I can separate the strands into group pairs of conductors, which will increase the capacitance further. plus litz helps reduce losses due to low radial volume of copper per strand. 

Ok, off I go to spin land.

Mags