Re: Some more Marx questions (fwd)

["High Voltage list" <hvlist@xxxxxxxxxx>]

Original poster: Steven Roys <sroys@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Wed, 5 Jul 2006 08:47:38 -0700
From: Jonathan Peakall <jpeakall@xxxxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Some more Marx questions (fwd)

Dr,

I was hoping to avoid the use of high voltage relays. I am just a poor
after-school science teacher, so I have to keep things on the cheap. I do
have all the stuff to make and program a controller, so all I would need are
the relays.

Could I use a Villard style multiplier circuit instead? Looking at it, it
seems it would work. Although it would be nice to be able to completely
control the system as you describe. Maybe I'll poke around and see what I
can come up with in terms of HV contacters.

Thanks for the help. I have built a 5 stage cap/spark gap setup, now to
figure out how to power it...

Jonathan
www.madlabs.info


----- Original Message -----
From: "High Voltage list" <hvlist@xxxxxxxxxx>
To: "hvlist" <hvlist@xxxxxxxxxx>
Sent: Monday, July 03, 2006 4:07 AM
Subject: Re: Some more Marx questions (fwd)


> Original poster: Steven Roys <sroys@xxxxxxxxxx>
>
>
>
> ---------- Forwarded message ----------
> Date: Sun, 2 Jul 2006 11:04:24 -0500
> From: Dr. Resonance <resonance@xxxxxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: Re: Some more Marx questions (fwd)
>
>
> The circuit I supplied works fine --- we use it on some of our Marx
> generators.  Just be sure to use a PLC or other timing device to
> automatically disconnect the power supply from the Marx circuit just prior
> to firing --- if connected the back pulse could damage the diodes.  We do
> this on all of our Marx generators using a cheap $150 PLC to control
charge,
> disconnect, and firing relays.  Using a PLC to control the primary
contactor
> and separate HV contactor allows for 1 sec buzzer warning, then 20 sec
> charging, then 1/2 sec disconnect, then 1 sec buzzer, one more sec delay,
> then firing.
>
> The HV charge relay uses a 1 inch stroke solenoid attached to a phenolic
> strip to multiply (lever action) the stroke by 3 (3 inch spacing) to
> disconnect the power supply 1/2 sec before the Marx fires.  This is for 30
> kV charging --- longer stroke necessary for higher stage charge voltages.
>
> Dr. Resonance
>
>
> >
> > I'm slowly working on my Marx. The 6 kV diodes arrived, so I made some
> > 42kV
> > strings with 7 diodes per string. I put them into some nice little tubes
I
> > had, and the used brass tubing at the ends for the contacts. Fits nicely
> > into a standard fuse holder.
> >
> > Anyway, to the questions: The diagram from Dr. R and others for the
> > voltage
> > doubler with a center tapped transformer has the ground seperate from
the
> > negative side of the doubler. All the Marx schematics I see show the arc
> > going to ground. In my case, I would want the arc to go to the negative
> > side
> > of the supply for maximum spark, right?
> >
> > It seems however, that arrangment would be hard on the power supply. So,
> > can
> > anyone point me to a schematic that uses a center tapped transformer
with
> > a
> > doubler to feed a Marx bank?
> >
> > Many, many thanks for all the help!
> >
> > Jonathan
> > www.madlabs.info
> >
> >
> >
> >
> >
>
>
>
>
>