STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM

[k4zep]

Very nice Ben !
Well done ! Great BackEMF recycling circuit.

Did you just use a diode ?
What diode ?
Do you have a very fast diode ?
It will help.
Like MU5xxx types or so..

The energy comes from the stored magnetic field energy from the toroidal coil.
W= 0.5LI^2

Ben, as you switch on about 20 x tau
you need to go to higher supply voltages and
lower ontime intervals, so you will reduce the ontime
to less than tau=L/R.

This way you could scale the motor up
and could recycle almost all of your input energy back to the cap,
if you stay below about 1/5th of tau for the ontime.

With higher supply  voltage you will then already reach in a shorter
time interval the same input current level as you reach now
after longer time.

I studied this all long time ago already with the Newman coils,
so I know quite well what is going on there.


Many thanks again Ben, you are a real help here.

Very well done.
Regards, Stefan.

Hi Stefan,

Now you said a mouthful there.  I would like to run several hundred volts and let that QuadF coil do its magic.  It stores a lot more energy than we suspect.  And I'm not certain it doesn't store energy from the magnetic field passing as in produces energy!.  How much I DONT KNOW. Room for months of experimentation and I love R&D.  This will not be a long winter with this good stuff going on! That said, I would have to have a much more precise timing circuit.  Have done this before with opto and 1-2 ms pulse around  5-700 volts,  But that is another story and won't go there.  Not using HS diode, 1N4007, probably would be better with schotkey diode which I have on hand but this was just a quick test.

Respectfully
Ben

[hartiberlin]

Well
in your last video Ben,
you have charged the 60,000 uF cap= 0.068 Farad cap
in about 27 seconds from zero to about 6 Volts,
that means an energy storage of
W= 0.5 x 0.068 x (6 Volts)^2=1.224 Wattsseconds
Then divide this by 27 seconds and you get a power level
of about 45 MilliWatts, so it is in the same range as the charging of the
Bootcap tells us.

This is a valid level for BackEMF extraction, as your coil has not too much L
inductance and only bigger power levels could be extracted, if you will
have a higher inductance coil L.

[k4zep]

Hmm, seems to me that you are recovering 35 milliWatts while charging the cap.
At what voltage level did you measure this ?
As the cap charge ramp is only linear around 0 Volts and then goes into
a e-function it really depends on the voltage level the cap already has...

I will have another look at your last video and look into this to calculate
the recycled power level.

Always start @ 0VDC.  And you are right, it is a non-linear curve.

[k4zep]

Well
in your last video Ben,
you have charged the 60,000 uF cap= 0.068 Farad cap
in about 27 seconds from zero to about 6 Volts,
that means an energy storage of
W= 0.5 x 0.068 x (6 Volts)^2=1.224 Wattsseconds
Then divide this by 27 seconds and you get a power level
of about 45 MilliWatts, so it is in the same range as the charging of the
Bootcap tells us.

This is a valid level for BackEMF extraction, as your coil has not too much L
inductance and only bigger power levels could be extracted, if you will
have a higher inductance coil L.

Excellent. Thats about what I got.  Good work.  I use the Electronics 2000 calculator that I found on line and saved to my ol HP computer that does that too.......lazy.

Respectfully
Ben

[k4zep]

Several questions as to how coil is wound.  Pictorial attached.

Respectfully
Ben