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RE: review of diode defence,6 pulse rectifier



Original poster: "Leigh Copp" <Leigh.Copp@xxxxxxxxxxx>

Hi Jim,

The 7th diode stack I was referring to is a freewheeling diode stack. To
be honest, this is normally reserved for controlled rectifiers with
SCRs, where continuous current is not assured over the full operating
range.

Leigh


-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: October 4, 2006 10:00 PM
To: tesla@xxxxxxxxxx
Subject: review of diode defence,6 pulse rectifier

Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>

....100k ohms in parallel with 0.1 uF is very common when we have a 6-40
amp
DC supply to work with (BTW: my frame of reference is 50-800kW plate
supplies). The resulting losses may be unacceptable with the size of
your dc supply (1.4 amp diodes were mentioned?), however, so you may
need to increase "R" and "C".

Reverse recovery time is not really the issue as was said, we just want
to buy time when we have a fault, and things start to ring (like that
big choke!)

With that much series inductance btw, consider a 7th diode stack across
Vdc as close to the rectifier terminals as possible. -This- rectifier
could benefit from reduced turn off time.
***** are you speaking to what is otherwise know as dequing in resonance
charging or something different as in slamming the door? I assume there
should be a few more diodes in this string as it sees the full forward
and
reverse voltage, I still need to call their tech support and will
adivise****

Cheers,
Leigh

***regards Jim Mora***