MOT charging anomaly partly resolved (fwd)

["Tesla list" <tesla-at-xxxxxxxxxx>]

Original poster: Tesla List Moderator <mod1-at-poodle.pupman-dot-com>



---------- Forwarded message ----------
Date: Tue, 05 Dec 2000 19:48:04 +0100
From: Finn Hammer <f-hammer-at-post5.tele.dk>
To: Tesla List <tesla-at-pupman-dot-com>, Tesla-2 Mailing List <tesla-2-at-emachine-dot-com>
Subject: MOT charging anomaly partly resolved

Gang!
I knocked the magnetic shunts out of the MOT`s last night, and today I
tried them out: no difference.

Also tried to wind some extra turns on a spare MOT, to bring the open
circuit current down. 20 extra turns did wonders, and lowered the
current to 50% of the original value.

But I didn`t want to do this modification right now, so I fired the coil
up, and started to play with the settings.

One thing was on my mind, and this was, that if I lowered the voltage to
the MOT`s, this would be equivalent to adding more turns, so thought so
done. At 160 volts input, I was able to take a lot of the current
limiting inductance out, and suddenly the picture changed: the strange
ramp with the ripples disappeared, and a more normal charging scheme
emerged. Moving the electrodes relative to each other showed that the
responce was now predictable.

The ability to adjust voltage, current and SRSG timing while the coil
runs, while looking at the interaction of the changes on the scope is
extremely rewarding. At last: a step beyond poking around in the dark.

I got a fast snap (still trying to get the digital camera to do decent
snaps)

http://home5.inet.tele.dk/f-hammer/charging5-12.jpg

Not optimal,(which to me means: equal bangsize) but still displaying
normal transformer responce.

Unfortunately, something started to smell at this point: the center
electrode (which is no doubt going to be the achilles heel of this coil)
had developed a gap, and was rapidly burning away. It`s copper for the
upper part, and a change to all tungsten is now indicated.

Running the coil inside the small basement workshop at more or less full
output would normally not have been possible, if I had not completely
shorted the toroid to ground.

Cheers, Finn Hammer