```Original poster: "Kurt Schraner" <k.schraner@xxxxxxxxxxx>

Tesla list wrote:
```
```Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx>

At 09:12 PM 3/26/2007, you wrote:
```
```Original poster: "Kurt Schraner" <k.schraner@xxxxxxxxxxx>

Hi Gerry,

before talking about the experiment: I'm shure, a slow ramp up will
_not_ cause the rods to rock! It's certainly the repeated
application of a small force, in the Eigenresonant frequency of the
JL, which does the job.
```
```
I'm sort of jumping in late here, and I forgot if this has already
been discussed, but I had always assumed that the movement in jacobs
ladder rods was from one of two source:
a) magnetic repulsion from the current flowing in the rods forcing
them apart.. as the gap grows, the current is reduced, and the force
lessens, causing the rods to move back together.
b) some thermal/convection effects.. the arc is hot, and air moves
past it pretty fast, and I think that might have an effect on the
rods (pulling them together)
```
```
Hi Jim,

```
I generally concur with your review of the situation, as long as the Jacobsladder is used in its usual way, with the climbing arcs.
```
```
BTW: In our case, we have tried to determine the induction-coil short circuit current, by measuring it with a moving iron armature ammeter, and have found a value of 0.4A(rms). Well, may be not very precise, but should give an order of magnitude (measured at the same conditions, as our experiment). I've not yet calculated the repelling magnetic force (with spark), which should be compared to the attracting electric force (without spark, at ~50-60kV). (JL heigth is 2m; average distance of rods ~5cm; rod diameter 0.8cm).
```
But:
```
Our mode of operation, is not the one, a jacobsladder is usually operated: we start the moving of the rods of the JL _without_ any sparks, and can continue this ad libitum, just by manually swiching the HV to the JL, in rhythmic manner(~1Hz). This was also elaborated in a former posting of this thread. When arcs in "JL-oscillator"-mode occur, they start at the _top_ of the ladder, and are only doing automatically, what we did before manually: replacing the wasted energy, and triggering the oscillation in the right rhytm. This can be seen in the movie of my initial posting. For the comfort:
```
http://twfpowerelectronics.com/~kurt/InductionCoils/P1000671.MOV

```
An experiment, proposed by Gerry Reynolds, which also is demonstrating the electric/elecrostatic-force influence, was posted yesterday.
```
Best regards,
Kurt

```