Abstract: This invention relates to a vehicle air conditioning device and defroster having a control circuit for controlling a compressor, an outdoor air/inner air change-over door and a blower fan for air conditioning the vehicle room. A control switch is provided for a rear window heater wire for defrosting the window pane of the vehicle containing the wire. The vehicle air conditioner is operated in response to the operation of the rear window heater when it is energized. The rear window heater wire is turned on manually or automatically in response to an outdoor frost sensor. The compressor is operated to defrost when the outdoor air temperature is higher than the allowable operating temperature in the compressor. During operation of the control switch, the outdoor air/inner air change-over door is controlled, when the air temperature is lower than a selected allowable operating temperature, so as to increase the feeding rate of the outdoor air or to increase the feeding volume of the outdoor air.

Abstract: An apparatus for detecting a trouble condition of an air conditioner of an automobile automatically and displaying it as change of air distribution condition is equipped with a trouble detecting circuit for diagnosing the area of a trouble and for outputting a trouble signal therefrom. A drive control means is provided for operating an intake changeover device or a mode changeover device using the trouble signal from the trouble detecting circuit so as to indicate the diagnosed trouble area by controlling the air distribution.

Abstract: In an apparatus for controlling blowing mode of a car air-conditioner, a position of a shutter for changing the blowing mode is continuously changed in accordance with a control signal which depends upon at least the air temperature outside car. The control signal is applied to the actuator to position the shutter at an appropriate position in response to the ambient conditions.

Abstract: A sensor (24) is provided to sense the humidity at the inner surface of a window of a vehicle interior. When the sensed surface humidity is above a certain value, the possibility of the window being fogged arises and a humidifier (28) is de-energized. The humidifier (28) is normally operated to increase the interior humidity to within a desirable range. When the surface humidity is above a higher value, the air interior air control system is operated to reduce the interior humidity by turning on a defroster or the like in accordance with the outside air temperature.

Abstract: An air conditioning system for preventing the fogging of vehicle windows includes a defroster switch which is closed to turn on a compressor when the temperature at or around the surfaces of an evaporator drops down to a predetermined off mode level. When the temperature outside the vehicle passenger compartment drops from a relatively high level to a first predetermined level, the off mode level becomes saturated to a constant (maximum) level. As the outside temperature further drops to reach a predetermined second temperature level, the off mode level is progressively lowered from the maximum level to a lower level. With this control, the compressor is turned on again after being closed by closing of the defroster switch, thereby permitting the vehicle windows to be cleared of the fogging from their inner surfaces.

Abstract: A sensor (27) is provided to sense the humidity at the inner surface of a window of a vehicle interior. When the sensed surface humidity is above a certain value, the possibility of the window being fogged arises and the proportion of outside air to recirculated air is increased to 100% to reduce the interior humidity. When the surface humidity is above a higher value, the interior air control system (5) is operated to reduce the interior humidity by increasing the amount of inlet air, the inlet air temperature, etc.

Abstract: In an apparatus for controlling the speed of the blower motor in response to the difference between the temperature setting and the temperature inside the vehicle, the maximum speed of the blower motor is limited in accordance with the temperature of engine coolant. Consequently, the quantity of air issuing from the blower is always such that it does not make the passengers feel uncomfortable.

Abstract: A main duct (12) contains a heater (19) and has an upper air outlet (22). A bypass duct (31) has an inlet (32) communicating with the main duct (12) upstream of the heater (19) and an outlet (33) communicating with the upper air outlet (22). A humidifier (36) is provided in the bypass duct (31). The bypass duct (31) has a circulated air inlet (37) and a proportioning door (38) for controlling the amount of air entering the bypass duct (31) from the main duct (12) and the circulated air inlet (37) to enable temperature control of the humidified air which is discharged from the upper air outlet (22) against the driver's face. An air cleaner (71) may also be provided in the bypass duct (31) and operated with the humidifier (36).

Abstract: A control apparatus for glow plugs provided for a diesel engine is disclosed, in which the time for preheating of glow plugs prior to starting of the engine, that is, the time for applying an electric current to the glow plugs from a battery, is controlled according to such factors as engine temperature and battery voltage. When the engine is cold, control is carried out so that as the engine temperature is lower or the battery voltage is lower, the preheating time is more prolonged. Accordingly, an optimum preheating time is ensured. When the engine is warmed up, control is carried out so that even is a key switch is set at a preheating position, preheating is not effected whatsoever.