| 摘要 |
PURPOSE:To contrive to improve excellently operational performance by a method wherein setting temperature is automatically varied according to the kind of cover to be used. CONSTITUTION:A cover to be applied for an electric heating carpet is provided with the contrivance of a fiber weaving quantity, a fiber pitch and the like for obtaining sufficient heat conduction, also provided with some light permeable property. The light permeable property is fairly related with the thickness of the cover. By applying said light permeability, the light permeable quantity is detected with a light receiving element arranged the inside of a case 12, the conpensation for a temperature control setting value is applied according to the detected value. A heating element 2 is controlled to be coincided with the setting temperature applied to an inversion inputting terminal of a comparator CP. The setting voltage obtained by a resistance value Rvr of a variable resistor VR as a temperature adjuster, and by resistors R1, R2 and R3 is applied to the inversion inputting terminal of the comparator CP, then the voltage is compensated according to the permeated light quantity via the cover due to the resistance variation of a phototransistor PHTr connected to the both ends of the resistor R1. Therefore, the carpet can be kept under adequate temperature in any application condition, accordingly, the operational performance can be contrived to be improved exceedingly. |
