RE: Dead MMC. was: AAAA! My coil...

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Mccauley, Daniel H by way of Terry Fritz <twftesla-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>


Are you actually running your coil with this set-up or just connecting your
MMC to the output of your NST ? ? ?

Dan





Well, crud.

After reading the list posts and seeing that most everybody agreed on
raising the resistors away from the perfboard, I raised the resistors off
the perfboard by about 1/2 of an inch. I then put a small square of plywood
underneath the one resistor that is in the spot that keeps getting blown,
to better insulate it. I then fired it up. Instantaneously, there was a
spark in that area, and I shut it down again. However, I noticed that the
carbon mark was only on the top of the wood, not on the bottom or sides
indicating an arc. I didn't pay much attention to it at first, and thinking
it was solely the resistors fault, I took out the blasted one and didn't
put in a new one. I figured the charge would just bleed into the other
adajacent resistors. When the coil was fired up again, it worked okay for
about 20 seconds, then a loud 'pop', and I recognized that special type of
orange glow by the MMC. I rushed over, blew out the small fire, and took
the coi! l in for the night. Rrrgh... there is a beautiful (sarcasm) black
crater about 1/4 of an inch diameter in the top of the cap that the failed
resistors were right underneath. So my coil is now declared dead untill we
can get another cap.

However, since there was no evidence of an arc, and the cap failed seconds
after I removed the resistor, and since every other cap and resistor are
doing fine, could the problem be the cap? It might have been that the cap
was shorting out, dumping the charge across the resistor, and when the
resistor was removed it simply carried the current itself and blew up. Any
ideas?

Also, (sorry about so many questions) someone told me that with 2 strings
of 6 geek caps, the mmc is not suited to handle the voltages at the peak
voltage. (9000VAC r.m.s. voltage, much higher peak voltage) however, the
geek group recommended the current setup, so am I okay as is or do I need
to redo my mmc completly? (I thought I was doing fine, now I'm confused
again). Thanks.


-Chris