At 15.17 2012.02.19, you wrote:
>I'm actually just charging them to somewhere between 40-50V.=20
>
>There is also a derating of Urms when used at higher frequency. The higher=
=20
>values start to derate at just above 1kHz.

You're right, but it's hard to understand how it applies to a *pulse* capac=
itor that
is (relatively) slowly charged, and then dumped in 30 microseconds into the=
 load.

As it's a CDI, the max frequency that this process repeats is 250Hz (15000 =
RPM), but
I rather suspect that I should apply the Fourier Transform when I evaluate =
that part
of the datasheet. The problem is that in this case we get frequences of 33.=
3KHz and
multiples of that (harmonics, but they are not continuous while those graph=
s are for
continuous use as far as I understand it. So I simply consider just the dU/=
dt limits.

Sometimes I wish the data sheets were more clear, expecially in this case a=
s it's a
capacitor expressely rated for pulse applications.

But maybe it's just me that has a hard time to read the data sheet in an un=
ambiguous
way. :(


>
>/Ruben
>
>
>>=20
>> Thanks. If I may ask, to what max DC voltage do you charge these 250V un=
its?
>>=20
>> I assume that charging to the rated voltage is safe, but the doubt=20
>is there. Of
>> course at ambient temperature.
>>=20
>> Cheers,
>> Mario
>>=20
>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D
>Ruben J=F6nsson
>AB Liros Electronic
>Box 9124, 200 39 Malm=F6, Sweden
>TEL INT +46 40142078
>FAX INT +46 40947388
>ruben@pp.sbbs.se
>=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D
>
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