Method for controlling combined sensing type clothes dryer

A method for controlling a drying operation of a clothes dryer including a drum, a heat exchanging fan, a motor, a heater and a microcomputer for controlling the drying operation, comprising the steps of:

• turning on the heater and the motor at the beginning of the drying operation and checking a drying operation time t, to determine whether the drying operation time t has exceeded a predetermined time t.sub.SH ;
• calculating a value Q indicative of the fabric quantity, based on a temperature variation .DELTA.X per unit time and a humidity value of exhaust air, when the drying operation time t has exceeded the predetermined time t.sub.SH ;
• primarily determining whether the fabric quantity corresponds to a small fabric quantity, based on a currently sensed temperature and the temperature variation .DELTA.X, after the calculation of the fabric quantity value Q;
• performing a small fabric quantity-drying operation by turning the motor on for a predetermined time, when the fabric quantity has been determined as the small fabric quantity at the primary small fabric quantity determination step;
• determining whether the fabric quantity value Q is higher than a first reference value K for an excessive fabric quantity determination, when the fabric quantity has not been determined as the small fabric quantity, so as to determine whether the fabric quantity is an excessive fabric quantity;
• performing an excessive fabric quantity-drying operation, when the fabric quantity has been determined as the excessive fabric quantity at the excessive fabric quantity determination step, the excessive fabric quantity-drying operation including a drying operation carried out until the humidity value is not higher than a third predetermined reference value and carrying out an additional drying operation following the excessive fabric quantity-drying operation;
• determining whether the fabric quantity value Q is lower than a second predetermined reference value T.sub.8, when the fabric quantity has not been determined as the excessive fabric quantity, so that a determination is secondarily made about whether the fabric quantity is the small fabric quantity, so as to reduce an error of fabric quantity determination caused by an ambient temperature;
• determining the fabric quantity as a large fabric quantity, when the fabric quantity value Q has been determined to be equal to or higher than the second predetermined reference value T.sub.8 and performing a large fabric quantity-drying operation, based on the temperature variation and the humidity value;
• and
• cooling the clothes for a predetermined cooling time under the condition that the heater is turned off, but the motor is driven, after completing the small fabric quantity-drying operation, the large fabric quantity-drying operation or the excessive fabric quantity-drying operation, so as to complete the overall drying operation.

A method for controlling a drying operation of a clothes dryer having a heat exchanging fan, a motor for driving a drum and a heater, in accordance with a fabric quantity of clothes being dried, comprising the steps of:

• turning on said heater and said motor at the beginning of said drying operation;
• checking whether a predetermined time t.sub.SH has lapsed since the beginning of the drying operation;
• obtaining a temperature variation per unit time and a humidity value of the air being exhausted out of said drum by said heat exchanging fan, when said predetermined time t.sub.SH is checked to have lapsed;
• calculating an arithmetical mean of said temperature variation per unit time and said humidity value;
• determining a fabric quantity value based on said calculating step;
• primarily determining whether the fabric quantity corresponds to a small fabric quantity, based on a currently sensed temperature and the temperature variation, after the calculation of the fabric quantity value;
• performing a small quantity-drying operation by controlling the motor for a predetermined time, when the fabric quantity has been determined as the small fabric quantity at the primary small fabric quantity determination step;
• determining whether the fabric quantity value is higher than a first reference value k for an excessive fabric quantity determination, when the fabric quantity has not been determined as the small fabric quantity, so as to determine whether the fabric quantity is an excessive fabric quantity;
• performing an excessive quantity-drying operation, when the fabric quantity has been determined as the excessive fabric quantity at the excessive fabric quantity determination step, the excessive fabric quantity-drying operation including a drying operation carried out until the humidity value is not higher than a third predetermined reference value and carrying out an additional drying operation following the excessive fabric quantity-drying operation;
• determining whether the fabric quantity value is lower than a second predetermined reference value T.sub.B, when the fabric quantity has not been determined as the excessive fabric quantity, so that a determination is secondarily made about whether the fabric quantity is the small fabric quantity, so as to reduce an error of fabric quantity determination caused by an ambient temperature;
• determining the fabric quantity as a large fabric quantity, when the fabric quantity value has been determined to be equal to or higher than the second predetermined reference value t.sub.B and performing a large fabric quantity-drying operation, based on the temperature variation and the humidity value;
• and
• cooling the clothes for a predetermined cooling time with the heater turned off, and the motor being driven, after completing the small fabric quantity-drying operation, the large fabric quantity-drying operation or the excessive fabric quantity-drying operation, so as to complete the overall drying operation.