--- On Tue, 9/16/08, Albert <[EMAIL PROTECTED]> wrote:
> From: Albert <[EMAIL PROTECTED]>
> Subject: [Repeater-Builder] Volt-Amp (Re: APC UPS Charging Power)
> To: Repeater-Builder@yahoogroups.com
> Date: Tuesday, September 16, 2008, 5:12 PM
> Hopefully you will forgive me hijacking the post but this
> brings up a
> question I have had for a long time. What on earth is a
> "volt-amp".
> My logic would state that is is the same as a watt, which
> is volts x
> amps, as you probably well know. So what on earth is is?
>
> Confused.....
>
> Albert
>
>
If you only have a resistance element then the watt and volt-amp are the same.
It should really be VAR or volt-amp reactive. If the load has a very high
reactance (capacitive or inductive) , the volt and amp will be out of phase.
That is the maximum point on a voltage curve will not be at the same time as
the maximum amp point. When you turn on a switch from a battery going through
a resistor and put a voltmeter across the capacitor and an amp meter in series,
the voltmeter will slowly start to rise and the amp meter will read maximum and
then fall. This is a crude example as how the current and voltage get out of
phase.
