| 摘要 |
PURPOSE:To eliminate the influence of fluctuation of power supply voltage onto the maximum current, by varying the current flowing through light emission diodes in accordance to the ambient temperature, in an automatic car air-conditioner employing light emission diodes. CONSTITUTION:Voltage division signal of inner air temperature thermister 2 and resistor 3 and power supply voltage signal divided by resistors 21a, 21b are input through a converter 4 to a microcomputer 1. The microcomputer 1 will operate cooling/warming cycle control to obtain forward current through light emission diodes 10a, 10b on the basis of stored characteristic thus to obtain firing time (t). Then the control target position of air mix door 7 is calculated to obtain applying voltage of blower motor 9 thus to control the blower motor 9 through a fan controller 8. Here necessary interruption processing is performed to detect/correct the air mix door 7 position by means of feedback position signal 16. With such arrangement, the influence of fluctuation of power supply source voltage can be prevented. |
