The latest Russian replication of Rossi appears to demonstrate a perfect example of a human controlled oscillator. With a COP of greater than 2, the internal heat power generated within the core is capable of regeneration since it is a form of positive feedback. In this particular case there is 1.7 times as much heat power(COP~2.7) being produced by the core than is needed in order to produce the output measured average power.
If the input power remains constant, the output can easily regenerate itself and allow the device to overheat which might lead to self destruction. My previous work on positive thermal feedback models shows this mechanism as the indication that a negative resistance type of region exits for the device thermal characteristics. A plot of input power versus core temperature contains a negative slope that does not permit stable operation within its borders. If a negative feedback control signal is introduced to counter this tendency the device can be rescued from destruction. In this case the scientist has the ability to adjust downwards the transformer voltage being applied to the heating coil. He effectively removes input power that is greater than the amount of core increased power during a finite period of time causing a reversal to the direction of device heating. My model indicates that when positive feedback is controlling a thermal feedback device the temperature can go in either direction at an accelerating rate. So, once the input power has been sufficiently reduced to reverse the temperature movement of the core, the device will head in a negative temperature direction toward cut off. This movement will continue until the negative resistance region is exited at the low temperature end or in this case to when the scientists decides it is time to increase the heater voltage and hence power. For this reason the overall temperature plots appear to have a periodic, nearly sinusoidal shape. The period of the oscillation is determined by the internal device time constants plus additional effects due to the adjustment routine used by the human operator. I consider this oscillator behavior an excellent additional indication of proof that the Rossi effect is taking place during the experiment. If a negative resistance region were not present then a fixed and nearly constant output power level would be obtainable for any constant input power applied to the heating coil. We should celebrate since the proof of useful LENR is becoming more evident every day as new replications are revealed. Dave
