In reply to David Roberson's message of Wed, 22 Aug 2012 01:29:06 -0400 (EDT): Hi, [snip] > >Yes, it might be possible to control the device by limiting the fuel as you >suggest. Once you sense something and use that information to adjust the >fuel, you have enclosed the positive feedback inside a negative feedback loop. > Are you thinking of running the device effectively open loop by fixing the >amount of fuel supplied? If you do it this way I would expect it to behave >pretty much as I first discussed. It would be quite difficult to achieve >perfect balance for long stable operation.
As you suggest, achieving *continuous* control would be difficult (but perhaps not impossible), however that may also not be necessary. You could supply the fuel in small rapid pulses none of which are large enough to allow the device to destroy itself, and control power production by controlling the pulse rate &/or duration. In a sense this is what Rossi is already doing, but perhaps, if the rate were increased, and the pulse size reduced, it would give an outward appearance of continuous power output. Actually more than an appearance since the thermal mass of the device would effectively smooth the pulses into a continuous thermal output. The smaller and faster the pulses, the more effective the smoothing would be (just as a fixed size capacitor is better at smoothing higher frequencies than lower ones). And of course, as you suggest, also control the cooling. [snip] Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
