The cabin air temperature is continually measured by the cabin air temperature sensor. When the cabin air temperature has been changed to be within 2°C or 35°F of the desired selection, the fan speed is gradually reduced.
Electrical servos incorporate limit switches to open circuit the current supply to the motor when the maximum travel of the flap or tap has been reached.
Most temperature sensors used in climate control systems are thermistors which are solid state electronic devices that change their electrical resistance in response to temperature changes.
The evaporator temperature sensor is located in the air stream where the air leaves the evaporator and signals to the control unit the temperature of the air.
A ventilation system is fitted to vehicles to make the environment in the cabin comfortable for its occupants. The ventilation system is controlled by a set of switches located on the dash.
