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Re: Panasonic polypropylene caps (was Tube coil capacitors

I don't know what the difference is, but I have quite a few of the ECQ-E
Panasonic capacitors in a .022 (224K) size, 1250 VDC - I get $16 per hundred
plus shipping - that's quit a bit cheaper than the prices for new ones
below, and these are new, in bags of 100.  The dielectric may be different,
I don't know what difference that will make, but if you want any of these,
contact me directly, off the list.  I don't have any other values, and I
won't have any at all once these are sold.


----- Original Message -----
From: Tesla List <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, February 20, 1999 2:42 PM
Subject: Panasonic polypropylene caps (was Tube coil capacitors


>Original Poster: Gary Lau  20-Feb-1999 1228 <lau-at-hdecad.ENET.dec-dot-com>
>
>>Original Poster: "Steve Young" <youngs-at-konnections-dot-com>
>>
>>These caps are probably fine (economical) for tube coilers operating at
>>much lower voltages than typical disruptive TCs.  But they don't appear
>>very economical for the latter.
>>
>>Based on Terry's experience, let's assume the caps can actually withstand
>>twice their rated voltage.  So each cap is .0056 uF at 3200 VDC.  If we
>>string 16 in series, we get .00035 uF at about 53 KV DC.  So a hundred of
>>them would give us 6 times that or .0021 uF.  For most coils we would need
>>an order of magnitude more capacitance, or about 1000 caps in
>>series-parallel.  So the cost would be probably $600 per 1000, based on
the
>>$69.75 per hundred price in the posts below.  That's expensive, and a lot
>>of soldering!
>
>The cost of these caps appears to go down as the capacitance goes up.
>While an array constructed out of .0056 uF caps would be expensive, the
>cost is much less using larger value caps.  This line of Panasonic
>polypropylene film caps, at 1600WVDC, goes all the way up to .056 uF.
>
>I've run the numbers using the four largest cap sizes available.  Prices
>are at the 100 piece qty.  I've assumed that a series-string of 16 is
>adequate, and calculated how many string would be required to achieve a
>.02 uf final value.
>
>Cap     Array   Final C         No. caps        Ea Cap          Final Cost
>.033uF  16x10   .0206uF         160             $1.64           $263.20
>.039uF  16x8    .0195uF         128             $1.77           $226.40
>.047uF  16x7    .0206uF         112             $2.00           $224.60
>.056uF  16x6    .0210uF          96             $2.15           $206.70
>
>It's unclear if there is an advantage to using many, lower value strings
>in parallel, to achieve a lower ESR value.
>
>Terry, the search engine on the archives seems to be down, how many units
>did you use in series?
>
><<<< I use 160 caps (0.1uF  630v) in four strings of 40 each.  They cost
>$0.712 each/100.  A 20Nf cap would be about $280 but you need to mount and
>connect them which adds about $50 if done up nice... If you by by the
>thousand they go down to $0.42ea/1000 ... - Terry >>>>
>
>Regards, Gary Lau
>Waltham, MA USA
>
>> Original Poster: Terry Fritz <twf-at-verinet-dot-com>
>>
>> Hi Dave,
>>
>> The ECWH(V) series on page 324 of the Jan-Mar. catalog look great.  They
>> were not available when I bought mine (pg. 322 P3521-ND  ECQP(U)).  The
>> things to watch for are dissipation factor and the word polypropylene.
>> These are both 0.1% at 1kHz.  The suggested applications of "high
>voltage,
>> high frequency, and high pulses" is another clue that they are made to
>> deliver high currents quickly with low loss.  Just the ticket for our
>> stuff.  These caps are probably better than the old micas.  One may have
>to
>> figure out which cap gives the needed value for the best price, but
>either
>> series should work very well.
>>
>> Terry
>>
>>
>>
>> At 09:34 AM 2/18/99 -0500, you wrote:
>> >Terry,
>> >   Your testimony is encouraging. I really like the idea of combining
>many
>> small
>> >value caps to produce just about any value desired. Let's make sure
>we're
>> >talking about  the same thing. These caps are found in Digikey's online
>> catalog
>> >at http://info.digikey-dot-com/EC/V3/324.pdf (Don't have their current paper
>> >catalog) and are called "High voltage Metallized Polypropylene Film
>> >Capacitors"--ECWH(V). The 1600 Vdc, .0056 uF caps sell for $69.75 for a
>> hundred.
>> >
>> >   Are we on the same page?
>> >Dave
>
>
>