Re: "lightning machine" at Chicago's Museum of Science & Industry? (fwd)

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

Original poster: Steven Roys <sroys@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Mon, 5 Jun 2006 10:25:49 -0500
From: Dr. John W. Gudenas <comsciprof@xxxxxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: "lightning machine" at Chicago's Museum of Science & Industry?
    (fwd)

Dave
I sort of grew up watching this Max generator.
First, it is not the GE device from 1939, which consisted of twin  
Marx towers at opposite polarity and was substantially larger.

I saw the first demonstration while I was in elementary school in the  
1950's. At that time the charging system for rather large and
consisted of using two large vacuum tube rectifiers. They would  
explode a 2x4 in the demo. You could hear the machine throughout the  
museum.

In the 1960's I was a senior in high school and worked week ends at  
the MSI. The "surge generator" as they referred to it frequently  
broke down and was a high maintenance item.

Off to college and degrees etc.

I likely saw the MSI Marx bank in its last cycle. My timing could be  
off here, albeit  is in an order of magnitude.
In the 1970's sometime to early 1980's the MSI Marx bank had been  
rebuilt with solid state rectifiers for the charging supply and more  
modern energy storage capacitors (much smaller than originals)
were installed. I saw the demo (this time with my young family) which  
was essentially the same. It was phased out sometime after that.

Forget any mystery associated with this exhibit, the MSI removed  
many  exhibits and is frequently changing the museum around.  DC  
indicates the energy caps had PCBs in them, perhaps
the museum board simply elected not to spend the cash to replace  
them. You just need to realize that it was a museum exhibit that ran  
it useful course (from the boards view). Stuff dissipates when it  
gets surplused out.
This device had no historical value and I doubt it (or its pieces)  
exist as there would be no reason to archive it. There are many Marx  
banks in research laboratories and universities around the world.
I sit on the Board of Directors of SciTech a local hands on museum, I  
kind of get some insight how these decisions are reached.
Hope this helps

John W. Gudenas, Ph.D.
Professor of Computer Science

On Jun 5, 2006, at 9:25 AM, High Voltage list wrote:

> Original poster: Steven Roys <sroys@xxxxxxxxxx>
>
>
>
> ---------- Forwarded message ----------
> Date: Fri, 02 Jun 2006 16:37:44 -0400
> From: David Speck <Dave@xxxxxxxxxxxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: Re: "lightning machine" at Chicago's Museum of Science &  
> Industry?
>     (fwd)
>
> Doc,
>
> By any chance was this the machine that had been featured at the GE
> Pavilion of the 1939 NY World's Fair?  The vintage and capabilities of
> the machine sound similar to what I've heard about the NYWF display.
>
> GE had both a Marx Generator and a multiple megavolt 3 phase  
> flaming arc
> display at that fair.    The transformers of the continuous display  
> were
> dispersed, some being used for test stands in Pittsfield, MA.  I never
> heard what happened to the Marx display.
>
> Dave
>
> High Voltage list wrote:
>> Original poster: Steven Roys <sroys@xxxxxxxxxx>
>>
>>
>>
>> ---------- Forwarded message ----------
>> Date: Fri, 2 Jun 2006 11:03:35 -0600
>> From: Dr. Resonance <resonance@xxxxxxxxxx>
>> To: High Voltage list <hvlist@xxxxxxxxxx>
>> Subject: Re: "lightning machine" at Chicago's Museum of Science &  
>> Industry?
>>     (fwd)
>>
>>
>>
>> It was not a Cockroft-Walton circuit. It was a classic Marx impulse
>> generator.  I repaired it for them several times.  The original  
>> design used
>> HV resistors that were too small and they kept frying.  The  
>> generator was
>> quickly and quitely removed from service when someone discovered  
>> the caps
>> were filled with PCBs.  It was a 1,000,000 Volt Marx generator.
>>
>> Dr. Resonance
>>
>>
>>
>>> Date: Thu, 1 Jun 2006 13:24:14 -0600
>>> From: Gomez Addams <gomez@xxxxxxxxxxxx>
>>> To: High Voltage list <hvlist@xxxxxxxxxx>, Tesla list  
>>> <tesla@xxxxxxxxxx>
>>> Subject: "lightning machine" at Chicago's Museum of Science &  
>>> Industry?
>>>
>>> This may have been asked on one of these lists before.  I may have
>>> even asked it myself a few years ago, because it's something I've
>>> been interested in for a long time, but if I ever did get an answer
>>> here, I didn't put it where I could find it again.  If I'm repeating
>>> myself, I apologize for my absent-mindedness.
>>>
>>> By the way, this isn't really Tesla coil related, but it's close
>>> enough it ought to interest many on the TC list, and I figure  
>>> someone
>>> else my age or older may know about it.
>>>
>>> So: in the 1970s, the Chicago Museum of Science and Industry had
>>> something which my high school science teacher called a "Lightning
>>> Machine".  We took a field trip there (from Peoria) but to my  
>>> dismay,
>>> they had shut it down only a few months before our visit.  According
>>> to the guide I talked to, they had found a hole in the ground cable
>>> which lead down from the second floor and into an elaborate ground
>>> system in the basement, and for that and other reasons (perhaps it
>>> had other problems) the powers that be had elected to not resume
>>> operating it.
>>>
>>
>>
>>
>>
>>
>
>
>

John W. Gudenas, Ph.D.
Professor of Computer Science