[Amps] HV Divider, Problem Solved

[Gary Schafer]

Scott,

Just ohms law: first you need to find the current thru the whole divider
between B+ and ground. E/R = I
In this case 10 meg + 50K. So then, 
2350/10050000 = .00023 amps.
Then use IxR = V to find the voltage across the 50k resistor. 
.00023 x 50000 = 11.69 volts.

73
Gary  K4FMX

> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
> Behalf Of KB0NLY
> Sent: Sunday, March 01, 2009 3:35 PM
> To: amps at contesting.com
> Subject: Re: [Amps] HV Divider, Problem Solved
> 
> The handbook is sitting right next to me and I still don't see the math
> I'm
> looking for.  I need the equation that I can fill in to determine the high
> voltage when I know the value of the string and the output of if, no meter
> involved other than a VOM to check the output of the divider.  See what
> I'm
> saying now?
> 
> Just a comment also on the handbook, a lot of you guys keep referring to
> it
> as the bible, well I have five editions of it and I still can't find some
> of
> the info that you guys know in it, and that's even with searching the .pdf
> version of it on the computer once I know the answer!  Seems to me the
> handbook is a bit lacking.
> 
> Thanks and 73,
> 
> Scott KBØNLY
> 
> 
> 
> ----- Original Message -----
> From: "Bob Maser" <bmaser at tampabay.rr.com>
> To: "KB0NLY" <kb0nly at mchsi.com>; <amps at contesting.com>
> Sent: Sunday, March 01, 2009 2:25 PM
> Subject: Re: [Amps] HV Divider, Problem Solved
> 
> 
> >I gave you the answer in my previous.  Read about measuring voltage using
> a
> > ammeter, which is what you are really doing.  Find a 1ma full scale
> > AMMETER
> > and use 5 megohms in the meter multiplier string.  When you connect the
> > AMMETER across the 100K ohm resistor and it will give you a full scale
> of
> > 5000V(1MA on the AMMETER.  If you insist on using the 10 megohm string
> > then
> > you will have a meter that is giving you a full scale of 10,000 volts.
> > Read
> > the Handbook.
> > Bob W6TR
> > ----- Original Message -----
> > From: "KB0NLY" <kb0nly at mchsi.com>
> > To: <amps at contesting.com>
> > Sent: Sunday, March 01, 2009 8:15 PM
> > Subject: [Amps] HV Divider, Problem Solved
> >
> >
> > Well i don't know how this amp was working before i started the
> > modifications but i pulled the resistor from B- to chassis ground, at an
> > AMPS member suggestion, to measure it, it was open!  So i grabbed an new
> > wirewound vitreous resistor out of the drawer and put it into place and
> it
> > now works perfectly and i have 11.68v off the divider.
> >
> > I'm not totally clear on the math here though, so if someone wanted to
> > comment here is my remaining question..
> >
> > I have 10 1M ohm resistors in series, so 10,000,000 ohms, and i have
> > 11.68v
> > off the divider.  How do i reverse the math to determine the value of
> the
> > high voltage knowing the output of the divider?  See what i'm saying?  I
> > know what i measured before using the HV meter, and i know what i have
> > after
> > the divider, just wanted to see if they match up.
> >
> > I have a level that will work with the board now, but i want to
> understand
> > it better.
> >
> > Thanks and 73,
> >
> > Scott KBØNLY
> >
> > _______________________________________________
> > Amps mailing list
> > Amps at contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
> 
> 
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