Amps
[Top] [All Lists]

Re: [Amps] alpha 91b help

To: Ron Spencer <genteknc@gmail.com>, <amps@contesting.com>
Subject: Re: [Amps] alpha 91b help
From: Rick Stealey <rstealey@hotmail.com>
Date: Wed, 15 Oct 2008 18:46:37 +0000
List-post: <amps@contesting.com">mailto:amps@contesting.com>

If that is a resistor that is in series with the primary of the power 
transformer that is supposed to be shorted out after a second or so it is very 
likely that you have a condition in either the transformer (not too likely) or 
in the power supply such as a shorted electrolytic or other device.
If it were me, I would make some meaurements in the B+ area first.  The filter 
caps are most suspicious.  If you find they are ok, then begin the process of 
elimination.  Use logic.  I'd first unhook the transformer HV leads and make 
sure the transformer is not shorted, etc.  

I think you likely have a serious case of high current in the power supply 
though.  I did some ohms law, and about 4 amps of startup current would be 160 
watts through that R.  But a fuse that is overloaded twice its rating probably 
will not open.  I bought some fuses recently and checked specs on them and if I 
remember correctly a typical fuse will last many, perhaps tens of seconds at a 
2 X overload.  I doubt that 15 watt R would last that long.  So that fuse is 
likely not serving any purpose !

Rick  K2XT




_________________________________________________________________
Stay up to date on your PC, the Web, and your mobile phone with Windows Live.
http://clk.atdmt.com/MRT/go/msnnkwxp1020093185mrt/direct/01/
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps

<Prev in Thread] Current Thread [Next in Thread>