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
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
> BTW, congratulations to Bert Pool for his latest magnifier
> What do others think?
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.