Transistor e.g. FET, controlling method for motor vehicle, involves adjusting width of pulse correspondence to hundred percent of nominal value, when set point is higher than predetermined threshold that is lower than specific percentage

摘要

#CMT# #/CMT# The method involves driving a transistor (4) e.g. FET, by a periodic pulse having a determined effective width based on a set point equal to a percentage of a nominal value of a functioning parameter of a cooling unit e.g. engine fan (2) of a heat engine (3). The width of the pulse is adjusted correspondence to 100 percent of the nominal value, when the set point is higher than the predetermined threshold that is lower than 100 percentage. #CMT#USE : #/CMT# Method for controlling a transistor e.g. FET and metal oxide semiconductor FET, connecting a power supply unit e.g. alternator and battery, to a cooling system e.g. engine fan, of a heat engine of a motor vehicle. #CMT#ADVANTAGE : #/CMT# The method ensures that the width of the pulse is equal to the period of the pulse such that the transistor is in permanent conduction, when the set point is beyond the threshold. The method avoids the switching of the transistor at high frequency under high temperature, thus avoiding the loss at the switching. The capacity is not solicited, due to the absence of switching of the transistor, thus modifying the width of the pulse in an optimum manner to avoid the use of the high cost components. The method is not necessary to implement in the degraded functioning mode for reducing the heating components. The method increases the availability of the cooling system. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a schematic view of a supplying device for implementing the transistor controlling method. 2 : Engine fan 3 : Heat engine 4 : Transistor 5 : Battery 6 : Electrochemical capacity 7 : Pulse width modulation type control circuit.