Re: How should we measure coil efficiency

From: 	Robert W. Stephens[SMTP:rwstephens-at-headwaters-dot-com]
Reply To: 	rwstephens-at-headwaters-dot-com
Sent: 	Thursday, July 24, 1997 10:04 AM
To: 	Tesla List
Cc: 	MALCOLM-at-directorate.wnp.ac.nz
Subject: 	Re: How should we measure coil efficiency

> From: 	Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
> Sent: 	Monday, July 21, 1997 10:29 PM
> To: 	tesla-at-pupman-dot-com
> Subject: 	Re: How should we measure coil efficiency
> Hi all,
>          My two cent's worth on this topic. I am simply after the 
> longest and hottest possible discharges for a _known_ primary power
> which is _easily_ and accurately measured as Ec x BPS. For a sync or 
> static gap system this is very well defined. For an async, scoping 
> using a HV probe can give an adjusted figure or a mean consumption 
> figure depending on whether one wishes to extract peak based 
> performance or mean power performance.
>      Forget the transformer type I say and forget transformer losses 
> in the gap. I know that this makes wallplug figures meaningless but 
> let's face it, they are largely meaningless anyway. If we are to 
> extract any meaningful figure of merit for different coils we simply 
> have to know as accurately as possible just how much power is going 
> into the primary. Failure to do this in the past has led to rules of 
> thumb for power vs length that have been counterclaimed one after the 
> other by actual working coil designs.
>      I am not interested in how far a coil can throw sparks to a 
> ground rod with a 100mph gale blowing around it. I am interested in 
> how far it can demonstrably reach (even just 10% of runtime) and 
> connect under favourable conditions. One of the magical qualities of 
> Tesla Coils is the ability "to reach out where no induction coil can 
> go". Let's use that quality and impress the hell out of the 
> neighbours.
>     BTW, congratulations to Bert Pool for his latest magnifier 
> experiments. 
> What do others think?
> Malcolm


I'm with you buddy all the way on what you just eloquently said.  
Your statement about the coil being able to reach out to extremes 
only 10% of the time as being a meaningful and qualifying number of 
merit is also representative of my own thoughts in this area but I 
think I am even less demanding in this respect.  I consider bonified
records made even if the long reachers are only occuring 1% or 2 % of 
the time.  This still ain't bad compared to the output efficiency of most lasers,
and I don't here any similar fuss from that camp!

BTW, I find I have moved to a location where it is very windy almost 
all the time.  As a consequence, until I get a higher ceiling in my 
test room to allow indoor testing of medium large systems, I unfortunately do
now have an interest in how far the streamers can go in a 100 mph wind!  : (

Ec x BPS sounds good to me.