Electric Door Actuators
Automotive air conditioning systems contain different electric door actuators (motors) that blend and distribute air through the duct system and into the passenger compartment. These actuators have replaced or work in unison with vacuum motors and Bowden cables. Automatic and semiautomatic air conditioning systems use electric motors controlled by a controller that can provide feedback on the blend doors in real-time.
Some motors provide two positions, either open or closed. An outside/recirculation mode door is an example of this type of motor. Others are variable-position actuators; a temperature blend door actuator is an example of this type of motor. It provides position feedback to the controller.
The controller uses voltage reversal to drive the motor back and forth. It receives input from the operator through the dash controller and from various input sensors. It then operates the compressor and the air mix and mode doors to provide the desired humidity and temperature settings. It's able to check the actual position of the door after making an adjustment with a potentiometer located inside the motor assembly.