-----Original Message----- From: Terry Blanton
> The concept would suggest that cooling is every bit as important in the > control loop as heating and that growing the output heat has to be > > Accomplished in a very balanced control of heat extraction, PWM triggering > over the threshold and adequate rest time to achieve usable output levels. Hence the PLC control of temperature in the Rossi device. BTW - We would be remiss if we did not mention PLC/PTC. "Positive Temperature Coefficient" (PTC) thermistors function quite well as self-regulating heating elements with only two wire input. We do not know if this is what is happening in the Rossi device as no schematic has been offered, but there are 5 separate PLCs shown in one image, each with paired binding posts, which someone indicated "apparently" lacked a feedback mechanism. That is incorrect. With PLC/PTC you do not need it. Of course, we do not know if feedback was accomplished with dedicated wiring not visible in the few pictures which we have, but independent RTDs and extra leads are not needed with self-regulating heating units. That could be the case here. In fact they downside of PTC thermistors is that they do tend to burn out faster than tape heaters.... which seems to have happened. Jones
