On 11/7/13 3:30 AM, Tuomas Koivurova wrote:
> Pulse capacitor is pretty inaccurate term to start with. There are "real"
> pulse capacitors that are rated for 1...10ms discharge times at few 10s of
> kA and they look just like good old PFC caps.
>
> Ofc most hobbyists think that only "real" pulse capacitors are the ones
> with ultra low inductance pancake style insulators and 100kA current
> ratings..
>
>
> 2013/11/7 Steve Ward <steve.ward@xxxxxxxxx>
>
>> Cant be a PFC cap, its only got 2 capacitors inside (not 3, as would be
>> required for 3 phase PFC). Also there is no KVAR rating, and the voltage
>> rating is in DC, so more signs that this is not a PFC cap. At the same
>> time, i dont see any indication that its a pulse capacitor.
>>
PFC caps are available in all sorts of configurations, I've seen dual
caps in one package. But, in general, PFC caps are marked with a kVAR
rating.
However, Tuomas is right. THere's lots of pulse rated capacitors out
there in a variety of configurations. Fruengel's book has hundreds of
pulse discharge applications, and there are hundreds of capacitors to match.
For instance, the big strobes used in lighthouses use pulse rated caps,
but with fairly low rep rates and discharge times.
Pulsed welding is another application where you probably have
multi-millisecond discharge times.
There's also pulse forming networks for radars. These days, most radars
use form of pulse compression, so the actual transmit time is quite long
(milliseconds). If you're looking at PFNs from the "Rad Lab" books,
life has moved quite a ways since the days of microsecond long pulses
out of a magnetron.
Then, there's tons of pulse applications for things like DC/DC
converters and motor drives.
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