On Tue, 09 Mar 2004 14:28:56 GMT Al wrote:

In article ,
Jim Adney wrote:

Okay, but why pick an identifiction method that requires a manual?
Most other components this size, including theirs, just have the
relevant numbers printed on them.

OK, let me give you a few example lines from the manual:

uF Case tol. Failure Rate (%/1000hrs) DC Leakage in uA
Code % 1.0 0.1 0.01 0.001 25C 85C 125C

5.6 A 5 5001 5201 5401 5601 0.3 6 7.5
5.6 A 10 2241 2481 2721 2961 0.3 6 7.5
6.8 A 5 5002 5202 5402 5602 0.3 6 7.5
6.8 A 10 2242 2482 2722 2962 0.3 6 7.5
6.8 A 20 2243 2483 2723 2963 0.3 6 7.5

So a M38003/01-5001 is unique. I left out the dissipation factor for
simplicty.

As you can see, there is much more information in this code number than
just the capacitance value and the voltage. When a component is bought
to this specification, it will meet it. If you buy a random FF uF VV
volt capacitor, you have no clue as to what you have with respect to
leakage, reliability, dissipation factor and the like.

I have a similar page here from the Sprague/Vishay catalog. In this
case it just happens to be for some caps which I picked up surplus
which are marked M39006/25-xxxx.

In this case the xxxx code pins down the tolerance and failure rate,
just as the Kemet does above (note that everything else above is the
same.) OTOH, the Sprague/Vishay caps are also labeled with their C and
V ratings, as well as the tolerance. Only the failure rate is left
unexplained. There is also an H-code for high vibration which you
might need the catalog page to interpret.

BTW, both manufacturers have a code for an M failure rate, which is
1.0% per 1000 hours. I find it hard to believe that anyone would buy
such a device, especially the military. The ones I got were the R
rate, .01% per 1000 hours. Those are the best that they offer and I'll
bet those are the only ones that ever get sold.

So I still don't think it's too much to ask that the most important
data be printed out separately.

Obviously, I don't tend to think like the military....

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Jim Adney
Madison, WI 53711 USA
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