Re: LF: Re: Re: 4kv diode

["Ken" <ken.h.wright@btinternet.com>]

Hi Paul.
If I could locate some BY1800 or BY2000 (1800v & 2000 V) that would be 
better, but again have not found a stockist, the BY255 were from Germany.
Ken

M0KHW


----- Original Message ----- 
From: "Paul-Henrik" <phl@netikka.fi>
To: <rsgb_lf_group@blacksheep.org>
Sent: Sunday, November 29, 2009 3:51 PM
Subject: Re: LF: Re: Re: 4kv diode


Ok Ken

Further I would not worry as much regarding the voltage rating of the 
equalizing
resistors. Use physically large units with an adequate power rating (U^2 / 
R)
and they will probably be fine. After all there are more stories out there
about blown diodes than equalizing resistor flash-overs.

Are you sure you can't squeeze in at least three diodes per leg? This would 
ease
the equalizing resistor voltage requirements a bit too. Just two BY255's per 
leg
sounds scary for 2.3kV peak.

BR

Paul-Henrik

Quoting Ken <ken.h.wright@btinternet.com>:

> Hi Paul.
> On my last mailing I got the BY255 current wrong.
>
> Ken
>
> M0KHW
>
> ----- Original Message -----
> From: "Paul-Henrik" <phl@netikka.fi>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: Sunday, November 29, 2009 2:45 PM
> Subject: Re: LF: Re: Re: 4kv diode
>
>
> BY255 should be a suitable building block rated 1300V PIV 3A.
>
> Use equalizing resistors in parallell with each diode, typical values used
> are
> 470...820kohm. Only controlled avalanche diodes can be series connected
> safely
> without a reverse voltage equalizing network.
>
> Make sure you implement a healthy safety marigin, ie. don't use just as 
> many
> diodes needed to acheive the needed voltage rating. Using 3 amp diodes 
> when
> 1
> amp is called for is no luxury either. You don't want to hear the sound of
> an
> angry rattlesnake from your thunderbox... this sound is often followed by
> popping and oozing electrolytic capacitors.
>
>
> Good luck and please don't get zapped
>
> Paul-Henrik
>
> Quoting mal hamilton <g3kevmal@talktalk.net>:
>
> > Yes series for more V  parallel for more I(amps) and preferable some R 
> > and
> > C
> > across each except they are really identical.
> > mal/g3kev
> >
> >   ----- Original Message -----
> >   From: David Towers
> >   To: rsgb_lf_group@blacksheep.org
> >   Sent: Sunday, November 29, 2009 12:37 PM
> >   Subject: Re: LF: Re: Re: 4kv diode
> >
> >
> >   Hi Mal
> >   surely "in series" to give a 4 KV diode at 1amp ?
> >   dave G8SZX
> >
> >
> >
> >   mal hamilton wrote:
> >     Ken
> >     On the serious side, use 6 x 1Kvolt @ 1A in parallel if u are stuck.
> >     Don't get zapped
> >     73 mal/g3kev
> >
> >       ----- Original Message -----
> >       From: mal hamilton
> >       To: rsgb_lf_group@blacksheep.org
> >       Sent: Sunday, November 29, 2009 11:28 AM
> >       Subject: LF: Re: 4kv diode
> >
> >
> >       Electric Chair Co
> >       Zapenda Cul de sac
> >       Hellda State
> >       Zip73
> >
> >         ----- Original Message -----
> >         From: Ken
> >         To: rsgb_lf_group@blacksheep.org
> >         Sent: Sunday, November 29, 2009 11:04 AM
> >         Subject: LF: 4kv diode
> >
> >
> >         Hello All.
> >         I am looking for a BY4 or BY6 or equivalent diode, BY4   4kv @ 
> > 1A,
> > BY6  6kv @ 1A, I have searched the web and looked in Farnell, any ideas
> > please.
> >
> >         73.
> >         Ken
> >
> >         M0KHW
> >
> >
> >