[Gllug] OT: Merging UPS outputs

[Chris Bell]

On Sun 04 Sep, Chris Hunter wrote:
> 
> Chris Bell wrote:
> 
> >    I assume that ferrite inductors can be used for filtering, and with care
> > could be used to protect the thyristor and allow time for the fuse to blow.
> 
> That's not really an effective method - you just have to rely on the 
> robustness of modern thyristors.  A triac will fail in microseconds, a 
> thyristor takes milliseconds - you can get fuses that are fast enough 
> for thyristors, but not for triacs.
> 
> When it comes to power supplies and modulators in the RF world, ferrites 
> can be used, but they're pretty nasty when you're trying to filter lots 
> of harmonic energy - they can get spectacularly hot (I've seen them glow 
> cherry-red before they explode!).  My approach is to slow the risetime 
> of the waveform, which radically reduces the harmonic content.
> 
> Chris
> 
> 
   Ferrites only work properly at high frequencies, so I would have assumed
that when correctly specified should be ideal for the job.
   I have been using variable output electronic flash, a discharge tube that
can be switched off. My portable units work over a range of several stops
without doing a power dump, but not sure about the 250 joule mains powered
units. The longest flash time is less than a millisecond, so the shortest is
probably a few microseconds. I do not have circuit diagrams.

-- 
Chris Bell

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