Shorting coil gives back more power

[wings]

shorting experiments:

http://www.advanced-science.com/CoilShortingNotes.html

[Dave45]

http://www.tfcbooks.com/tesla/nt_on_ac.htm#035
Tesla was shorting the coil peak to peak as well

[Magluvin]

Was testing a bifilar air coil 26awg 27mh with coil shorting on my pulse motor setup.

Was testing with the reed switching on the departing side of the coil and the approaching side.

The coil when the reed is opened oscillates about 14.3khz and dies off.

See scope shots below.

On the departing side, when the reed opens, the oscillation begins + and rises to the cap voltage(-diode v) and dumps into the cap.

But on the approaching side, the oscillation begins in the - direction full swing then back up into the + till it hits a point it is dumped into the cap. But the peak out is higher when the coil has its down swing first. Like it added momentum to the output. Same discharge width in both.

Now I have to see if thats the case with a normal coil. Normal coils do have some capacitance. But I wonder if it is the same gain.

Mags

[Magluvin]

With the coil alone at near same rotor speed p-p is about 6v.  In respect to the post above.

Mags

[Magluvin]

Ok, that was the bifi coil. Here is a normal coil below. About the same physical size coil but bigger wire. 1.65mh

The bifi shots were at 400us and these are seen at 80us. There is the oscillation but higher freq and much faster die down.

The coil was reverse wired to show that is all it takes to get the downward throw on the departing side.

But here the oscillation dies off so fast that it looks better to take the output when the oscillation is started on the up swing being that the next half wave is significantly reduced each swing. So the upward, most powerful swing of the oscillation shows to dump into the cap for a longer period of time. But waiting for the down swing and then the up swing there is a narrower dump time because that swing has a shorter peak.

The down then upward swing does have a bit more height at time to dump but is shorter lived.

So there does seem to be a little advantage in using a bifi coils here because taking advantage of the downward swing inertia doesnt let you loose much on the next swing because the oscillation doesnt die off so quickly on the next swing.

So when using shorting, to get the best results with a particular setup, use a scope to see what gives you the best output per time shorted. it seems to matter.

Mags