[Amps] HV fuses

[Jim Thomson]

Date: Fri, 25 Oct 2013 05:38:56 +0000
From: "Fuqua, Bill L" <wlfuqu00 at uky.edu>
To: Jim Garland <4cx250b at miamioh.edu>, "Amps at contesting.com"
<Amps at contesting.com>

Subject: Re: [Amps] HV fuses

   This does not sound right. I assume you are saying that they are glass fuses.
I suspect if you blow one in a HV powe rsupply it will shatter or explode into pieces if
you have a reasonable value of filter capacitor.  Do you have a data sheet on these
fuses? 
73
Bill wa4lav

##  why would they explode ?   Mine don’t.    The 50 ohm glitch R  LIMITS the current..and the
HV fuse  INTERRUPTS the fault current.   BTW,  you always put the HV fuse B4
the  glitch R.   Reason is, if the glitch was damaged, and dangling down  onto the chassis,  you 
want the HV fuse INBOARD  of any glitch, so the fuse will open. 
Yes, you can parallel em  for more current..and you can also  series em for more HV. 
You can also wire em series-parallel  for more current + Voltage. 

##  another useful place to insert a HV fuse is between EITHER plate xfmr secondary.....and the
FWB  or FWD.   Then if any B+ shorts  in the filter caps, or any problems inboard of the B+ fuse,
then you are still protected.   Dirt cheap insurance.   I have seen the AC  HV fuse blown open twice
and the B+  HV fuse blown several times... while de-bugging a new hb RF deck.  

Later....    Jim   VE7RF