Re: Wattmeter

To: tesla-at-pupman-dot-com
Subject: Re: Wattmeter
From: "Steve Young" <youngs-at-konnections-dot-com> (by way of Terry Fritz <twf-at-verinet-dot-com>)
Date: Sat, 23 Jan 1999 22:14:50 -0700
Approved: twf-at-verinet-dot-com

Recently, someone asked about the feasibility of using a watt-hour meter as
a means of measuring wattage, but noone responded.  Suppose one uses a
watt-hour meter of the type that is commonly used to bill us for our home
power useage.  If one monitors just the TC HV transformer (pig, nst, pt)
for a precise time such as 60 or 100 seconds, will one get a fairly
accurate indication of average power?  Does mechanical inertia, etc. take
care of the erratic waveforms it must handle?  I like the almost
indestructable character of watt-hour meters--they seem to live forever.

--Steve

 

<SNIP>----------
> An electronic
> Wattmeter must take scaled samples of the voltage and the current in the
> load, multiply them, average the result, and take the square root.
> Any other approach will not work correctly with arbitrary waveforms.
> 
> Antonio Carlos M. de Queiroz
> 
> 
>