Re: Voltage Multiplier(4x) problems

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

Original poster: "Robert Jones" <alwynj48-at-earthlink-dot-net> 

Hi,

Make certain the secondary circuit is connected to ground and no other metal
or circuit is floating including the core.  If not the inevitable leakage
caused by corona and conduction can cause them to float to some high voltage
and then spark to ground or mains power. You can kill a floating scope this
way just by having it near by.

The corona wind can charge up any floating metal work then it sparks to
ground or shocks you. This can even happen with AC.   I have even been
charged by the corona wind from a point then when I touched a power switch I
got a jolt as I discharged myself past the plastic toggle to what may have
been the mains power.

Once you get in to the 10kV and above range points and even small diameter
wire can cause break down across gaps much longer than expected. So one
string of Cs may be fine but an other with solder points breaks down
occasionally.   Check the archives and web sites for good practice.

In the dark particularly after your eyes are dark adapted you should be able
to see were the corona is.

Just a reminder:   Be extremely careful in the dark with exposed voltages.

Bob
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, January 11, 2004 2:37 PM
Subject: Voltage Multiplier(4x) problems


 > Original poster: "Hydrogen18" <hydrogen18-at-hydrogen18-dot-com>
 >
 > I just completed a 4 stage voltage multiplier made with 12 kilavolt 350 ma
 > diodes and 10 kilavolt 500 pf capacitors(dielectric). It works fine with a
 > 2500 VAC input from a mot other than a few problems. I get crackling
corona
 > everywhere and ionic force between clipleads but I was aiming for that.
 >
 > I will occasionally get arcs from the core to the primary. I'm guessing
the
 > 10 kilavolts somehow makes it way backwards and ends up somewhere on the
 > core then arcs to the primary because 120 volts looks alot like 0 when you
 > have a 10 kilavolt supply. It doesnt seem to effect anything negatively,
 > but I am concerned that the insulation may finally fail and the 120volts
 > will connect to the core. Am I right or wrong about why the core arcs to
 > the primary?
 >
 > I connected one of the 10 kilavolt capacitors(bought 50, used 8 for the
 > multiplier section) across the output of the multiplier to give me more
 > burst amperage(doubled the spark length). For some reason the leads will
 > arc over on it if I do not discharge it often enough. I'm guessing the
 > voltage builds up enough then finally arcs. What I dont understand is why
 > the heck the ones in the multiplier circuit dont also arc, it would seem
 > they should since they are exposed to 10 kilavolt stresses as well. Any
 > ideas? I am now using 20 kilavolt 500pf doorknobs without any problem.
 >
 > Another problem is trying to figure out whether the capacitors are failing
 > or not. I thought I heard one in the multiplier hissing, but it was near
 > where I had a clip lead clipped on, so I'm guessing it was corona "hiss".
 > What does a failing capacitor sound like and what are the visual
indictations?
 >
 > Thanks for any help you can provide.
 >
 >
 >