Re: A "Revolutionary" Idea

To: tesla-at-poodle.pupman-dot-com
Subject: Re: A "Revolutionary" Idea
From: Tesla List <tesla-at-stic-dot-net>
Date: Sat, 22 Mar 1997 15:44:36 -0600
Approved: tesla-at-stic-dot-net

Subject: 
           Re: A "Revolutionary" Idea
      Date: 
           Sat, 22 Mar 1997 10:27:41 -0800
      From: 
           Greg Leyh <lod-at-pacbell-dot-net>
        To: 
           Tesla List <tesla-at-pupman-dot-com>
References: 
           1

Joe Cummings wrote:

> At present I'm not able to do any practical work, so all I do is carry
> out
> Gedankenforschungen - thought experiments.

[snip]

> Now, has anyone tried staggering a number of electrodes on the rotor, so
> that there
> 
>  is more than one spark per rev, or x sparks per rev, depending on the
> number of electrodes on the stator?

Good idea -- this concept is used in many applications, from spinning
noise-makers to the tick marks on vernier calipers.  However, in a
SG the mechanical dwell time should be as short as practicable, on 
the order of 200uS or less.  Therefore a 1/4" wide electrode on the 
rotor needs to have an edge speed of nearly 0.5 mach in order to
quench efficiently, and not shunt significant amounts of current from
the prime power source.  Perhaps the ideal geometry for an SG would be
to 
have a 18" diameter composite rotor with 2 breaks/rev, and spin the 
armature at 12000 RPM, in order to achieve 400 PPS with minimal dwell
time.

-GL