| 摘要 |
PROBLEM TO BE SOLVED: To adjust the capacity of a defogger in response to circumferential environment, that is, a condition of frost deformation. SOLUTION: When ambient temperature is, for example, below 0 deg.C, based on a signal from an ambient temperature sensor 3, electric power is supplied to a defogger R by way of a contact (a) through a contact (b) and a contact (c) ((a) is a middle point of (b) and (c)) via relays 4 and 5. As compared with electric power ordinarily supplied by way of the contact (b) through the contact (c), electric power supplied as mentioned above comes up to be four times as much as that, defrosting can thereby be smoothly performed. Besides, when the difference between internal air temperature and ambient temperature is great, frost and the like can easily be formed. For this reason, a signal from an internal temperature sensor 9 is taken into consideration, and when, for example, ambient temperature is below 5 deg.C, and when its temperature difference is equal to or more than 15 deg.C, electric power increased by a factor of four is supplied. When ambient temperature is below 0 deg.C, and if ambient temperature at night has been detected by a solar radiation sensor 6, an ignition switch is turned on, and when an alternator 7 thereby starts operating, electric power increased by a factor of four is supplied regardless of a defogger switch 2 turned on/off. |
