Re: Series or Parallel???

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

Original poster: "sundog by way of Terry Fritz <twftesla-at-qwest-dot-net>" <sundog-at-timeship-dot-net>

Hi All,
    Mkay, I'm gonna let my ignorance show ;)

  I've paralleled 1N4007's without any trouble on both my pig and my MOT 
supply.  While I can see where problems would arise at high frequency due 
to the speed of the diodes, the 1N4007 is a decently fast diode, and should 
handle 60hz without any trouble. I may (and probably am) wrong, but I've 
yet to smoke a FWR using paralleled diodes.  I derate them by 1/2 the 
current because of the high surges in TC use, and it's done me good so 
far.  YMMV



At 07:49 AM 3/26/02 -0700, you wrote:
>Original poster: "Matthew Smith by way of Terry Fritz 
><twftesla-at-qwest-dot-net>" <matt-at-kbc-dot-net.au>
>
>Hi Gregg/All
>
> > In the diagram of the link below, you can either use a microwave oven
> > diode or 12 1N4007 diodes.  Can someone tell me if you use 12 1N4007's, do
> > you use these in series or parallel?
>
>Series - end to end - cathode to anode (or anode to cathode if you're
>left handed ;-)  1N4007's are rated at 1000V -at- 1A each.  By connecting
>in series, the voltage across the whole string is effectively divided by
>12 (or however many diodes you are using), meaning that the string could
>cope with [ 1000V -at- 1A ] x 12 = [ 12kV -at- 1A ].
>
>1N4007's are nice and cheap so there's no harm in over-rating by adding
>more diodes to the string.  Just allow yourself plenty of time to solder
>them all together ;-)
>
>I am reliably informed that diodes may not be used in parallel, so you
>can't do this to up the current rating.  (They switch on at slightly
>different speeds and the first one on takes all the juice...)
>
>Cheers
>
>Matthew Smith

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Shad (Sundog)
G-2 #1203
"Ever stop to think, and forget to start again?"
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