[Prev][Next][Index][Thread]

Re: On the measurement of watts (fwd)





---------- Forwarded message ----------
Date: Sun, 2 Mar 1997 01:11:30 -0700
From: "DR.RESONANCE" <DR.RESONANCE-at-next-wave-dot-net>
To: Tesla List <mod1-at-pupman-dot-com>
Subject: Re: On the measurement of watts (fwd)

to: DWP on Power Measurements

It is very important to remember when running spark gap excited units that
the maximum instataneous power is very important not the average power.  As
an example while a cap is recharging through a pole transformer and power
limiting reactor arrangement is may draw up to 50 kiloWatts of instataneous
power before the saturation curve of the reactor is reached.  This provides
a tremendous burst of recharging energy for the capacitor even though the
system is operating at a recharging power average of 5-10 kiloWatts.

If you happen to be running a typical power reactor you will note that if
you wind it with 12 AWG wire and run it on a 5-7 KW system it will get very
hot even though it is only pulling 20-25 amps at 240 VAC.  You will have to
use 8 AWG wire to wind this reactor because the pole transformer efficiency
is very high and pulls maximum instataneous peaks in excess of 10 times the
average running power level.  These sharp peaks occuring only for 300-400
microseconds several times each second but they can overheat a power
reactor designed for an average load.

John Couture, a retired Electrical Engineer from San Diego, has published
information on this effect which has been long overlooked by many large
coil designers.  An exception is Bill Wysock who once stated that tuning
the power supply is as important as tuning the oscillator itself.  

DR.RESONANCE
----------
> From: Tesla List <mod1-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: On the measurement of watts (fwd)
> Date: Saturday,March 01,1997 2:08 PM
> 
> 
> 
> ---------- Forwarded message ----------
> Date: Fri, 28 Feb 97 09:48:20 EST
> From: pierson-at-gone.ENET.dec-dot-com
> To: mail11:;;;;-at-us4rmc.pko.dec-dot-com-at-us4rmc.pko.dec-dot-com-at-digital-dot-com;;;
(-at-teslatech)
> Subject: On the measurement of watts
> 
> !> (1) Measure power input (watts, not V.A.)
> 
> !Maybe a dumb question: How do *YOU* measure watts?
> 
> 	Several Ways.
> 	1) assuming the usual ac lf type input, "four wire wattmeters"
> 	are standard devices.  The have two coils, one for voltage, 	
> 	one for current and measure both, simultaneously.  Not cheap,
> 	but thats one way.
> 
> 	2) arguably more common, esp if one has friends at the power co
> 	are wattHOUR meters, as on your house.  A used one, duly wired up,
> 	would yield watthours, divide out the hours and there you are.
> 
> 	3)read watthour meter on the house with and without coil (or whatever)
> 	operating, subtract out the 'house load' and proceed as in 2.
> 
> 	[nb:  The meters above read TRUE WATTS, not VA.  The placement of
> 	coils internally is such as to measure IN PHASE product.]
> 
> 	4) various electronic 'true power' meters with a variety of
> 	internal multipliers for getting the inphase component of E and
> 	I and displaying it.
> 
> 	5) A digitizing scope, can, in general, be set up to do the math in
> 	real time.
> 
> 	6) I bet there are others...
> 
> IMO, it would be real interesting and instructive to do E, I and P with a
> coil just below breakout, and same coild sparking heavily.
> 
> 	regards
> 	dwp