[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Big MMC, final question, 2nd request



Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>

High temp is one aspect of using silver solder, but mechanical strength is the other. Common tin-lead solder should be fine for this application, but if there is a desire to add a higher fatigue property, then silver solder is a good choice. However, like Gary mentioned, really unnecessary here. For tin-lead solder, if you do want to aid mechanical strength, ensure a large surface area of the leads are joined and soldered.

Take care,
Bart

Tesla list wrote:

Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>

I think that silver solder is unnecessary.  It's only used if the
temperature of the joint approaches the melting point of conventional
Pb/Sn solder.  If your MMC gets that hot, you have another problem.
While it may be argued that silver solder has a higher electrical
conductivity, I doubt it would be significant.

I also wouldn't get too hung up on geometries that cancel capacitor body
inductance.  Unless you have an OLTC or something else where such
inductance amounts to a significant component of the total Lp, it just
doesn't matter.  There is no loss mechanism associated with lead
inductance.  You just have to adjust the tap and coupling a very tiny
bit.

Regards, Gary Lau
MA, USA

> Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>
>
> Hi All,
>
> I could use some feedback before I start cutting up my horde of CD
caps. I
> bought these over some period of time!
>
> Thanks,
> Jim Mora
>
>
> -----Original Message-----
> From: Tesla list [mailto:tesla@xxxxxxxxxx]
> Sent: Saturday, November 25, 2006 8:35 AM
> To: tesla@xxxxxxxxxx
> Subject: Big MMC, final question
>
> Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>
>
> Hello All,
>
> I'm going to begin construction of the 396 CD.15 capacitor mmc soon, I
have
> properly sized bare crimps for the two resistor junction, and the caps
which
> will be carefully crimped then soldered with silver bearing solder.
I'll
> slide a small diameter Teflon tube over the resistor splice. I'll try
to
> make these like an assembly line, cutting the leads to length, bending
the
> resistors, Etc. I'll fully assemble a few to get the hang of it and
> determine if tinning is needed first (-f and plain) (and get the lead
> lengths).
>
> This cap will be comprised of 18 strings of 22ea .15 CD caps for a
total of
> .123uf. The fist layer will be fixed at .06uf. The second layer will
have
> each row detachable for multiple cap sizes. Here's my question:
>
> I would like to make the lexan plates ~22" long and 12" wide. This
would
> accommodate 9 strings in a upright configuration. The plates would
then be
> stood upright long-ways with stand off spacers to coerce cooling. I
would
> stager the cap joints so there would be no mutual inductance,
something like
> this:
>
> _|-|_|-|_...X (22)
>
> _   _   _...
>    |_| |_|
>
>
> Since these are adjacent, this would tend to cancel the mutual
inductance,
> yes? This is not the serpentine rows suggested, although they are
still
> strings in series which will cancel the overall inductance. Is this a
poor
> or a good design?
>
> Thanks Much,
> Jim Mora
>