| 摘要 |
PURPOSE:To enable heat generation to be effectively restrained by providing thermosensible elements for sensing the heat generation adjacent to a fixed contact in a contact mechanism for adjusting the operation of an air blasting means so as to control a blow-out temperature adjusting means in the case of sensing heat generation more than a predetermined value. CONSTITUTION:The direct current motor 20 of a servo mechanism for driving an air mix damper (called 'damper' hereafter) is controlled by means of an automatic temperature control circuit 30, so as to make a damper opening set at a desired opening according to respective outputs from a temperature setter 30a, inner/outer air temperature sensors 30b, 30c, and a potentiometer 30d for detecting the damper opening. Thereat, fixed resistances 30e, 30f are connected to the automatic temperature control circuit 30. In addition, adjacent to both end potions of the fixed contact 71 in a program switch mechanism 70 are provided thermo-switches 76, 77 which are opened in the case that heating temperature becomes more than a predetermined value. And then, when the thermo-switches 76, 77 are opened, resistance values of the fixed resistances 30e, 30f are added so that the rotation of the direct current motor 20 is controlled by the predetermined rotating angle. |
