| 摘要 |
Hair drier or clothes drier or other hot air blower for personal care comprises a heating resistor disposed in the path of air from the fan, and an electric motor for driving the fan rotor. In the path of hot air coming from the fan is a first temp. sensor (NTC, PTC, metal-film resistor, thermoelement, etc.), and on the housing of the fan unit is a second temp. sensor around which ambient air circulates. The two temp. sensors together control the output of the heating resistor via a control component with an electric switch e.g. an operational amplifier, by varying the pulse-interval ratio automatically in dependence on the respectively actual value. The arrangement allows thermostatic control within narrow limits according to room air temp. |
