Re: rectifier stack experts?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Crow Leader by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla-at-lists.symmetric-dot-net>

I've noticed mega rectifier assemblies are compensated. This makes sense as
switching transients easily diodes, and in a string, when one shorts out for
good, the stresses just go up on the rest of them. Then eventually they all
break down and get destroyed. I'm assuming the use of MOVs absorbs any
transients that might otherwise permanently destroy a diode. As for how to
desing this properly, I have not clue at all. I was using large 1N5600 (5kV,
2A) diodes before they shorted out.

KEN

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, October 18, 2002 8:18 PM
Subject: Re: rectifier stack experts?


> Original poster: "Daniel Barrett by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <dbarrett1-at-austin.rr-dot-com>
>
>     Not an expert, but I doubt compensation will help. I've blown about
500
> 1N4007's figuring out that reverse recovery time is very important -
rapidly
> discharging your filter cap will kill these diode because they take a long
> time (milliseconds) to turn off, plenty of time to exceed the 50uA reverse
> current rating by about 5 order of magnitude. I have started using
> fast-recovery diodes(UF4007, 75nS) in my HV rectifiers and haven't fried
one
> yet.
> db

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