>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.
? at 35 or so kHz, this could be important.
> 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.
? So use a 50% safety factor. 1N5408s are not expensive.
> 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.
>
? I agree.
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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