Rich says;
>However, without equalization resistors, there is equal reverse current in
each >diode -- provided that the diodes are similar.
Not quite - they should be identical. Minor point, apparently, but mixing
from batches is a no-no.You may well need to use diodes from adjacent sites
on the same wafer if you are going to push to the rated voltage limit,
because of the requirement to get capacities equal. Choosing diodes for
equal breakdown voltages can lead you astray. 'Soft' breakdowns don't
necessarily give the full answer, because break down volts reduces with
temperature, but they do help. If you're buying your diodes 'loose' you've
really no guarantee about 'batch' matching; it's slighty better if you buy
them bandoliered, but there's still no guarantee. I suspect that using
under-voltage rated resistors is probably worse than using a bandolier of
diodes and no resistors.
73
Peter G3RZP
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