RE: MMC cap preferences? (fwd)

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

Original poster: <sroys@xxxxxxxxxxxxxxxxx>



---------- Forwarded message ----------
Date: Thu, 10 Mar 2005 20:45:12 -0800
From: Dave Halliday <dh@xxxxxxxxxxxxxx>
To: 'High Voltage list' <hvlist@xxxxxxxxxx>
Subject: RE: MMC cap preferences? (fwd)

If you look at the other post tonight on this subject, you will see that
the recommended cap is 

  "The ones most popular are made by Cornell Dubilier,
  they are 0.15 uF at 2000 VDC, part number 942C20P15K."

These sell at RELL for $2.45
http://catalog.rell.com/rellecom/scripts/SkuPage.asp?SKU=162589&PNO=&PNM
=

These are more expensive per unit __but__ doing some arithmetic we see
that they have a bit over three times the capacitance (plus the higher
working voltage = more safety margin) for a bit less than 1.5 times more
money.

Looking at this another way, if you needed to buy 60 of the Newmark
caps, you would only need to buy 20 of the RELL ones.
Newmark = $99 / RELL = $49

With RELL, you do need to buy a specific minimum quantity that they
quote you in the web page but it's always good to get ten or so extras
because you will blow up the occasional cap and this way, you are back
in operation immediately.

Finally, the C-D 942 series is known to be the best for MMC work.  There
may be newer technologies coming out that will work better but I have
not heard of anything else being used now.  The Vishay may be fine but
it is not known how it works in Tesla applications. If you wanna spend a
hundred bucks on something that may blow up in the first five minutes of
operation, feel free and please let us know about it.  <big grin>

Dave

> -----Original Message-----
> From: High Voltage list [mailto:hvlist@xxxxxxxxxx] 
> Sent: Thursday, March 10, 2005 6:37 PM
> To: hvlist
> Subject: MMC cap preferences? (fwd)
> 
> 
> Original poster: <sroys@xxxxxxxxxxxxxxxxx>
> 
> 
> 
> ---------- Forwarded message ----------
> Date: Mon, 7 Mar 2005 15:28:25 -0700
> From: Gomez Addams <gomez@xxxxxxxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Cc: Colorado Tesla Coilers <gnats@xxxxxxxxxx>
> Subject: MMC cap preferences?
> 
> What is the current recommended basic capacitor from which to 
> build MMC  
> banks?  The reason I ask is that I just got a flyer from Newark  
> advertising a metallized propylene cap from Vishay, specifically  
> intended for high voltage, high frequency, high current, high pulse  
> applications.
> 
>   Maximum pulse rise times range from 133v/uS to 9610v/uS 
> depending on  
> lead spacing and voltage rating.
> 
> Highest rating: 1600 V, 0.047 uF, $1.65 ea. in singles. Newark stk#  
> 65C0858, Vishay# MKP1841347134.
> 
>   - B(G)L
> 
> ..............................................................
> .......... 
> ........
> "A physical experiment which makes a bang is always worth 
> more than a  
> quiet one.
> Therefore a man cannot strongly enough ask of Heaven: if it wants to  
> let him
> discover something, may it be something that makes a bang.  It will  
> resound into
> eternity."  - Georg Christoph Lichtenberg 1742-1799
> 
> 
> 
>