What is the principle of an electronic expansion valve controller?

[Lola]

The principle of an electronic expansion valve controller is: 1. Electromagnetic expansion valve: It controls the system flow through an electromagnetic coil as the medium. Before the coil is energized, the valve needle remains open. After energization, the opening degree of the valve needle is controlled by the voltage on the electromagnetic coil to regulate the valve's flow. 2. Motorized expansion valve: It is a device driven by a stepper motor, where the logical digital signal provided to the stepper motor controls the internal threaded drive to move the valve needle. Components of an electronic expansion valve: 1. Rotor: Equivalent to the rotor of a synchronous motor, it connects to the valve stem to control the opening size of the valve orifice. 2. Stator: Equivalent to the stator of a synchronous motor; it converts electrical energy into a magnetic field to drive the rotor. 3. Valve needle: Driven by the rotor, its tapered end moves up and down to adjust the flow. 4. Valve body: Made of brass.

[VonJosie]

The electronic expansion valve controller regulates refrigerant flow by receiving signals from the air conditioning system sensors. Simply put, the AC computer constantly monitors data such as cabin temperature, evaporator temperature, and system pressure. When cooling intensity needs adjustment, the computer sends command signals to the controller. Inside the controller is a precision stepper motor that drives the valve needle up and down to alter the valve opening degree. A larger valve opening allows greater refrigerant flow, while a smaller opening reduces flow. This real-time adjustment enables the AC to precisely maintain set temperatures, unlike old-style expansion valves that were prone to frosting. I particularly appreciate this smart design when driving - the AC saves fuel while maintaining consistent comfort, making long trips exceptionally pleasant.

[EliLee]

The automotive electronic expansion valve controller functions like an intelligent regulator for the air conditioning system. I've disassembled it to examine its internal structure, and found its core mechanism involves a microprocessor coordinating with a stepper motor. When the AC computer analyzes signals from temperature sensors, it calculates the optimal refrigerant flow rate. Upon receiving the command, the controller drives the stepper motor to rotate, which moves the valve spool up and down through a threaded mechanism. The displacement of the valve spool determines the flow area of the valve port, directly controlling the amount of refrigerant entering the evaporator. The entire process responds remarkably fast with virtually no perceptible delay. This precision control saves 15% more fuel compared to traditional thermal expansion valves, while significantly improving cooling efficiency. With this system, you'll never experience intermittent cooling during summer AC operation again.

[StPaul]

The operation of the electronic expansion valve controller mainly involves three steps: receiving signals, calculating commands, and driving the motor. I measured its working process with a multimeter. The controller receives voltage signals from the pressure sensor and temperature sensor, and the internal chip determines how much the valve needs to open based on the calculation requirements of the air conditioning computer. Then, it sends pulse signals to the stepper motor, causing the motor to rotate a specific angle. The motor's rotation is converted into linear motion of the valve needle through the gearbox, and the up-and-down movement of the valve needle changes the size of the refrigerant passage. The entire process takes only a fraction of a second, enabling real-time response to changes in vehicle speed, engine load, and other conditions.