respect to time the microprocessor generates an air flow restriction or blockage signal representing an air flow restriction or blockage in the dryer vent ducting application_number US 45534203 A description referring to fig1 a control system is shown for use with an automatic clothes dryer 10 wherein the dryer itself may be of any well known construction having a clothes drying drum 14 an air inlet to the drum an air outlet from the drum and air mover or blower for flowing dryer air as illustrated by arrows 16 through the drum 14 and out of the dryer 10 generally as is well known heater means 18 for example an electrical resistance heater may be provided for heating the dryer air at the air inlet side of the drum 14 in well known manner it should be understood that the heater means 18 may also comprise a combustion type of heater a temperature sensor or thermistor 20 is provided for sensing the temperature of the dryer air at the inlet side of the drum 14 preferably inlet thermistor 20 is placed in any convenient position within the inlet air flow so as to sense the temperature of the air flow without being directly influenced by direct radiation from the heater means 18 a suitable shield for this purpose may be provided the signal output of inlet thermistor 20 is a resistance value that varies with temperature the thermistor 20 is in a circuit not shown that.