Jaguars vs Victors

[Al Skierkiewicz]

Dean,
So lurkers are not confused, the power per device is not a max power spec on the FET but how much power is generated within the device during constant current due to the internal resistance. Please see that the ON resistance of the IRL3103 goes down as the Gate to source voltage goes up. The 12mohm is the more accurate figure. The fan in the Victor seems adequate, it is closely spaced with the devices and the airflow is constantly pushing air away from the tabs of the FETs. Everyone should keep in mind that although each leg has devices in parallel, there are two legs in series with the motor during operation. This series resistance also serves to limit that max current available to the motor. Under normal conditions, the devices do not achieve the indicated temperatures in either controller. If they did we would have had numerous reports of thermal issues over the years.