Re: Magnifier Primary Capacitors - EQUIDRIVE vs. STANDARD

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

Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com> 


I see what you're saying.  I'm going to do some more testing with my 50 kV
probe.

Dr. Resonance

 > At 09:56 AM 1/12/2004, you wrote:
 >
 > >A proposed experiment for active members of this list:
 >
 > I think a few of us have already "been there, done that" :o)))
 >
 >
 >
 > >In all the coils we have built we have never (in over 45 years) seen any
 > >charge remaining on a cap operating in an AC tank circuit.  I know Ed and
 > >others have reported that charge does remain with an equa-drive system,
but
 > >with the standard classic configuration I have never seen any residual
 > >charge whatsoever.
 >
 > MMCs are strung together much like the equidrive system.
 >
 >
 > >We operate a coil and we are tuning it and after shutdown we adjust the
 > >tuning tap and adjust the sparkgap usually within 60 seconds and we have
 > >never received an electric shock in any manner.  In theory, if you shut
off
 > >the coil at the exact AC peak, you should have some charge left but we
have
 > >never encountered any charge.
 >
 > Normally, the two outside cap terminals will be discharged back through
the
 > transformer.  "Normally" it will discharge.  You build really nice coils
 > that do not do abnormal things, but I am not sure all of us do ;-))
 >
 >
 > >I've often wondered why everyone goes through all the trouble of
soldering
 > >all those resistors across the MMC caps.  I've never done this and we
have
 > >never found an MMC that retains charge on an AC circuit.  I've been using
 > >MMC circuits for approx 3 yrs, and again, no residual charge remains.
 >
 > They have shocked "me"....  The outside higher voltage caps tend to corona
 > more causing a net DC current flow.  This tends to cause unequal voltage
 > build up across the string.  Shorting the outside terminals will certainly
 > drop the "sum" of the cap voltages to zero but they my be charged like
this:
 >
 > 0
 > 500
 > 1000
 > 2000
 > -2000
 > -1000
 > -500
 > 0
 >
 > The sum voltage is zero for the outside terminals, but don't go playing
 > with the individual caps!!  Guess how I know this :o)))
 >
 >
 > >If you are running DC in your system, then, of course, there will be
 > >residual charge on the cap.
 > >
 > >Other members of this list might wish to  verify this with volt meters on
 > >their systems.  I would be curious to know the results.  It would sure
save
 > >a lot of construction time with the resistors.  We never use them except
on
 > >DC circuits with Marx generators, etc.
 >
 > Might not be a good idea unless the meter can take a few thousand
 > volts!!  I have had charged MMC caps sitting for days that were still
 > easily able to knock one's socks off!!  Worse yet, after they are
 > discharged, they can again build up a charge due to that effect whose name
 > I can't remember at the moment....  With a resistor across them, they are
 > dead as a door nail...
 >
 >
 > >I've worked with Bill Wysock tuning a large coil (16 ft. spark length)
and
 > >he also never discharged the caps prior to making primary tuning
 > >adjustments.  We were even working directly on a 0.2 MFD cap within 60
 > >seconds of full power operation and no charge remained.
 >
 > The charge is being blead off though the charging circuit or the spinning
 > rotary gap knocks it down.  Or, Bill is just really tough ;-))  In his
 > case, he knows his coils well enough to trust them.  I do that too, but I
 > have the bleeder resistors there so there are three things to knock the
 > voltage out before it knocks me out.  For most of us, best to use
resistors
 > and such to be super safe.
 >
 >
 > >Terry F. with his HV probe on a TEK scope could leave the probe across
some
 > >MMC's and then shut the coil off.  I'm betting after 60 sec he sees
nothing
 > >or a value less than 60 Volts.  It has never shocked us so it has to be
very
 > >low if any remains.
 >
 > I could remove the resistors, short to two ends of the MMC to ground, and
 > charge the center to 15kV.... and then send it to you to test
 > yourself  >:o))))   I could also send you one just like it with the
 > resistors in place.  You see the difference?  ;-))  The real problem is
 > that the inside of the MMC can be touched too where goodness only knows
 > what charges may be waiting!
 >
 > Cheers,
 >
 >          Terry
 >
 >
 > >Dr. Resonance
 > >
 > >Resonance Research Corporation
 > >E11870 Shadylane Rd.
 > >Baraboo   WI   53913
 > > >
 > > > Electrically and performance-wise, two caps in series, no matter if
 > > > separated by the TC primary or back to back, act like a single cap
with
 > > > twice the voltage rating and half the capacitance of a single cap.
But
 > > > esthetically, it has some appeal for those who value symmetry and
 > >scientific
 > > > names to describe their setup.  One could argue two caps might help
 > >isolate
 > > > the primary from the 60 Hz power source, but the equidrive setup is
 > >probably
 > > > just as potentially lethal to the careless person who contacts a
primary
 > > > while the coil is in operation as is a single cap configuration.
 > > > --Steve Y.
 >
 >
 >