Re: reverse recovery time of 6 kV diodes from All-Electronics

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

The only thing I would wonder about is the following scenario...

The reverse recovery doesn't start until the diode is reverse biased and
reverse current starts to flow. With a slow AC waveform, the reverse voltage
climbs relatively slowly, and the diodes might not all turn off
simultaneously.  Maybe one turns off, and the charge stored in the junction
still is flowing through an adjacent diode (in the correct dirction?)


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, February 26, 2002 3:59 PM
Subject: Re: reverse recovery time of 6 kV diodes from All-Electronics


> Original poster: "Malcolm Watts by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>
>
> Hi Justin,
>
> On 26 Feb 2002, at 7:51, Tesla list wrote:
>
> > Original poster: "Justin Hays by way of Terry Fritz
<twftesla-at-qwest-dot-net>"
> <pyrotrons2000-at-yahoo-dot-com>
> >
> > Thank you Jim for posting this information. I have wondered about the
> > diode's Trr for quite some time now.
> >
> > I know they work great for rectifying the output of a flyback
> > transformers, as I have used them to do this at frequencies greater
> > than 100kHz. No problem for the diodes.
> >
> > This leads me to believe that these actually COULD rectify the output
> > of a Tesla coil. I wonder if it would work with spark-gap types, as a
> > BUNCH might have to be put in series for the initial voltage pulse
> > right after the gap fires.
> >
> > It looks especially promising for the solid-state and vacuum-tube
> > driven types as the output is very clean.
> >
> > Got a question for Jim and All: What does putting the diodes in
> > series do to the reverse recovery time (Trr) of the string? I have
> > been told by an engineer whom I know, that it doesn't affect it at
> > all. Trr remains the same, PIV' are added, and current handling
> > capability stays the same.
> >
> > Is this true?
>
> It should be since Trr is an intrinsic property of the diodes.
>
> Regards,
> malcolm
>
>
>