Re: Coil efficiency

To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
Subject: Re: Coil efficiency
From: Tesla List <tesla-at-stic-dot-net>
Date: Mon, 17 Nov 1997 23:40:29 -0600
Approved: tesla-at-stic-dot-net


From: 	Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
Sent: 	Monday, November 17, 1997 2:25 PM
To: 	Tesla List
Subject: 	Re: Coil efficiency

Hi Ted,

> From:   Ted[SMTP:tedric-at-generation-dot-net]
> Sent:   Sunday, November 16, 1997 2:44 PM
> To:     tesla-at-pupman-dot-com
> Subject:    Coil efficiency
> 
> Hi all,
> 
> I have this question in my mind for weeks: According to the 1996 (or any)
> edition of "The ARRL Handbook For Radio Amateurs", "the (coupling)
> coefficient with air-core coils may run as high as 0.6 or 0.7 if one coil is
> would over the other." This is logical to say that the maximum efficiency of
> a regular (3 air-core coils) magnifier system can never beyond 70%, yet I
> remember that in one of Richard Hull's tapes, Richard said that it can
> approaches 100%. How come?

K <> efficiency. Efficiency is solely a function of losses. If your 
secondary/extra coil "loses" all the power fed to it in output 
discharges on the first energy transfer, your efficiencies can be 
over 90%. Primary losses are the major governor of efficiency when 
this ideal is approached.
    If you look on the scope to see what is going on, you will see 
that at particular values of k, the primary goes completely to rest
at which point all energy (minus primary losses) resides in the 
resonator.

> Also, what is the maximum efficiency of a soild state magnifier? 

Depends on driver losses mostly. 

Malcolm