RE: FW: Re: Tesla Coil Efficiency Test

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi John,

On 17 Jun 2002, at 16:58, Tesla list wrote:

> Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
> 
> 
> Malcolm,
> 
> Because the load varies so widely is the reason I thought the "black box"
> method of finding the TC efficiency would be better. The incandescent lamp
> load means we have complete control over the black box output load. The lamp
> brightness will vary with slight changes in the coil and the light meter
> will detect the change. The voltage and current for this brightness can then
> be found very accurately giving the TC output energy for the coil to better
> than one percent.
> 
> The wall plug to variac losses would not be included in this test. However,
> these losses are very small compared to the total energy loss in the TC
> system. Note that I used a black box watts input based on the NST capacity
> and the voltage setting of the variac.  The variac output voltage and
> current should be measured to verify this input watts.
> 
> John Couture

Before the discussion gets bogged down perhaps we should start by 
defining exactly what we are trying to measure. Are we talking about 
the percentage of primary energy (on a shot-by-shot basis) that is 
being delivered to streamers? If so, are we talking about air 
streamers or attached streamers (the efficiencies for those two case 
will be vastly different)? Or the amount of primary energy that a TC 
can deliver (again on a shot-by-shot basis) to a well-defined 
resistive load?
Unless the load is defined, discussion won't be meaningful as the 
efficiency is load-dependent. By the same token, any efficiency 
figure measured for an incandescent lamp will not be applicable to 
sparks. Personally, I'm interested in getting greatest possible 
efficiency in turning electrical energy into hot glowing air.
     Just to add to the fun, the quality of the secondary ground is 
also going to matter. For example, if we tested two identical systems 
at the same altitude, same level of humidity, same degree of 
isolation from surroundings, same primary energy and breakrate, same 
type and size of cap etc. etc., we'd probably be comparing the 
quality of the grounding systems.

Regards,
malcolm
<snip>