| Have some HV caps and a DC flyback?
Build a small Marx generator.
The Marx structure consists by 4 plastic rulers glued to some CD covers as base supports.
Eight ceramic doorknobs, 470 pF@30 kV each (from HV stages of color TVs) are set in 8 stages along the rulers. HV resistors are made with 2 x 6 little 6M7@.25w in serie / stage (I know, a little too much, but my resistors are very short, so I have to put many in serie to prevent breakdown).
The gaps are made with metalic screws bought from a furniture store. The plastic rulers are flexible, so I can adjust the gaps with two white rubber gum pieces set between the rulers.
HV source: 2 paralleled DC flybacks driven with a Mazzilli driver
|FIRST STEP: 9-10 cm sparks with 10 kVDC input. I have some jitter on the gaps yet.|
| SECOND STEP:
I am waiting some longer resistors. Until then I made a new try with some slightly longer resistors, 9M1 each, covered sharp edges and higher voltage input (still having breakdown along resistors at 60% of maximum input, had to insulate the with plasticine).
Results: 13-14 cm sparks.
|MOVIE||Not al the sparks are captured by the camera, some of them are incomplete..)|
| THIRD STEP
Longer resistors.......maibe they will come finally.....
....and they came, but what desillusion...They are longer but with terminal metal caps, so they were shorted almost imediately along the surface. Desperately I used some low power 510 kohms resistors (2 in serie for 1 Mohm/ stage). The spark rate was higher and the sparks longer (the caps charge at higher voltage), but the base ones smoked in a few seconds. Here is what I used:
|I put again my trustfull 9M1 resistors and open the gaps a little more. I got 15-15,5 cm sparks, but soon the first two resistors (at the base) arced over. So the little game is over until I will get some good resistors.|