[Amps] plate voltage meter shunt

[Jim W7RY]

As I remember... Henry (I know the Viewstar/B&W works this way) does that in 
some of their amps. I've had mixed results. As the bleeders heat up and the 
caps do too, the plate voltage meter drifts. And the voltage is not the same 
across each cap. The one with the metering circuit has lower voltage across 
it.

73
Jim W7RY


-----Original Message----- 
From: Bill Turner
Sent: Saturday, November 03, 2012 7:22 PM
To: Amps
Subject: Re: [Amps] plate voltage meter shunt

ORIGINAL MESSAGE:
On Sat, 3 Nov 2012 14:15:44 -0700 (PDT), W9IIX wrote:

>I am installing a meter to measure plate voltage 1-5000v@ 1a dc,
>the meter has a 1ma fs rating.  the serial resistance I have
>made up in the past has been 3 watt metal film resistors in
>series. since they can only rated for 200v per resistor it takes
>many to do the job. Can some other resistor type with a
>higher rating be used in a safe manner for this purpose?
>...tnx, Doug,w9iix

REPLY:
Does your power supply have a string of electrolytic capacitor with 
equalizing
resistors across each one? Install the meter in series with the bottom 
(negative
end) resistor and shunt it with a potentiometer or fixed resistor for
calibration. A few minutes with Ohm's law will give you the values.

Hint: do the calculations based on the full scale reading of the meter, not 
the
actual HV reading.

73, Bill W6WRT
_______________________________________________
Amps mailing list
Amps at contesting.com
http://lists.contesting.com/mailman/listinfo/amps