Not without a lot of serious thinking.  The model is in the form of a spice 
file with non linear elements.  Perhaps this can be done, but I have not 
attempted it so far.

Could you explain what you plan to do with that information if it can be 
obtained?

Dave


-----Original Message-----
From: James Bowery <jabow...@gmail.com>
To: vortex-l <vortex-l@eskimo.com>
Sent: Sun, May 26, 2013 8:07 pm
Subject: Re: [Vo]: Constant temperature Operation of ECAT?


Could you post the differential equations of the control system?




On Sun, May 26, 2013 at 6:44 PM, David Roberson <dlrober...@aol.com> wrote:

My model demonstrates that constant temperature operation of the ECAT is not 
going to work under normal conditions.  The relatively high value of COP when 
temperature control is used depends upon operation in a positive feedback 
region.  This can be thought of as related to the question that always arises 
about why the device does not supply its own drive and therefore run 
continuously in SSM.

Once the loop gain becomes greater than 1, the device will tend to move in the 
direction that it is currently heading.  This allows it to heat up to a 
relatively larger temperature than that due to the drive alone.  When rising in 
temperature, the device begins to put out additional heat, more with time.  The 
trick is to turn the process around at a good point before it goes too far.  
The best turn around temperature is well defined and shows up as a tendency for 
the device to continue putting out power at a constant rate with time.  
Unfortunately, this exact point would be impossible to achieve while 
maintaining control.  It is a balance between how long you want the temperature 
to remain nearly constant and the risk of loosing control.

Rossi chose a relatively safe turn around temperature for the last test which 
caused the COP to drop below his desired value of 6.  I suspect he chose this 
because a COP of 3 well demonstrates that the process is real and also has 
enough margin to keep the device safe from melt down.  I think I would have 
done the same under the same constraints.

Dave

 




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