The role of Hall sensors in automobile window anti-pinch systems (automotive-grade Hall sensors application cases)

西安中科阿尔法

The role of Hall sensors in automobile window anti-pinch systems (automotive-grade Hall sensors application cases) [Copy link]

The role of Hall sensors in automobile window anti-pinch systems (automotive-grade Hall sensors application cases)

Electric windows are windows that use electricity as a power source to automatically raise and lower the window glass. The driver or passenger operates a switch to connect the circuit of the window lift motor, and the motor generates power through a series of mechanical transmissions. The electric window system is composed of windows, window lifters, motors, and control switches.

The window lifter is a door accessory in the door system that realizes the lifting and lowering movement of the window glass. It is a special component for adjusting the opening size of the window glass. Its function is to ensure that the window glass rises and falls smoothly and opens and closes smoothly.

Most car window lifters use a very flexible linkage to lift the window glass while keeping it level. A small electric motor is connected to a worm gear and several other spur gears to create a large gear reduction ratio to provide enough torque to raise the window.

In the car window control system, safety is the first priority. When the window moves up and down, a force of 200N-300N is generated, and the instantaneous force can reach 100N. If a child stretches his hands, arms or legs out of the window while playing, and the driver fails to notice this and closes the window, it is easy to cause a pinch injury to the child. In order to prevent the window from causing unnecessary harm to the human body, the electric window control system must strengthen safety protection measures. In the car window anti-pinch control system, Hall sensors play an important role.

The typical electric window structure is shown in the figure above, where the left side shows the mechanical structure of the electric window, and shows the motor lifting force FA, the friction force FF applied by the sealing strip, the deadweight FG, the resistance FO (i.e. the clamping force) when clamping obstacles, and the force FD caused by inertia when the car is bumpy on irregular roads. The right side is an anti-pinch module that integrates a motor and a Hall sensor. The anti-pinch judgment information all comes from the output signal of the sensor in the integrated module.

The working principle of electric window anti-pinch is to add a set of current sensors, and the Hall sensor always detects the speed of the motor. When the electric window is raised, once the speed of the electric motor slows down, the Hall sensor detects the change in speed and reports the information to the ECU module. The ECU module sends a command to the relay, and the circuit reverses the current to stop or reverse (drop) the motor, so the window stops moving or drops. Therefore, it has a certain anti-pinch function. This type of application is suitable for bipolar latch Hall sensors.

AH501/AH502/AH504/AH505 are Hall switch sensors designed based on BCDMOS process. The chip includes temperature compensation, comparator and output driver. In addition, mechanical stress has little effect on the magnetic parameters of the chip, which is suitable for industrial environment and automotive applications, and meets the AEC-Q100 automotive electronics industry test standard.

AH501/AH502/AH504/AH505 has three package types: TO92S, Small-SOT23, SOT23, and the package complies with RoHS standards. It is widely used in automotive electronics and industrial control industries.

Product Features

(1) Low power consumption: 2.5mA

(2) Operating voltage: 2.7 V ~ 30 V

(3) ESD up to: ±12KV

(4) Strong resistance to mechanical stress

(5) Temperature range: -40℃~150℃

(6) The power pin has reverse voltage protection

Typical Applications

(1) Speed and RPM Sensor

(2) Tachometer sensor

(3) Flow sensor

(4) DC motor

(5) Motor and fan control

(6) Robot control

(7) Proximity sensor

(8) Position sensor

(9) Safety buckle

(10) Hood/trunk door lock

(11) Sunroof/Convertible Top/Tailgate/Liftgate activation

(12) Brake/clutch pedal

(13) Electric Power Steering System (EPS)

(14) Transmission shifting

(15) Wiper motor

lugl4313820

Speaking of window lifters, I replaced mine last month and it cost me 400 dollars. Is this thing expensive?

西安中科阿尔法

Hello, thank you very much for your attention to our company.
Xi'an Zhongke Alpha Electronic Technology Co., Ltd. was established in 2016. The company's headquarters is located in Xi'an High-tech Zone, and its R&D centers are located in Surrey, UK and Freiburg, Germany. It is a company that designs, develops, produces and sells magnetic sensor SOC chips. It covers device design, SOC system design, magnetic circuit design, and module design. At present, the company has more than 10 domestic and foreign patents.
The company has independent and innovative core technologies and has developed various types of magnetic switch series chips, magnetic speed and direction sensor chips, linear sensor chips, and magnetic encoder chips. The products can be widely used in automobiles, industry, medical care, and home appliances.
The company has passed the ISO9001 quality certification system and TS16949 automotive-grade certification system.

The window lifter you mentioned is the application end of our product. Its principle is that the servo motor drives the rocker handle to rotate the gear to lift the window. It replaces the traditional turning handle to lift the glass. The
Hall sensor mainly plays the role of detecting the movement of the motor and the change of circuit current. During the process of raising and lowering the window, the Hall sensor can accurately measure the number of revolutions of the motor, thereby determining the current travel position of the window, so that when the window is raised and lowered to the specified position, the power can be turned off in time to stop the motor.

The cost of window lifts is mainly divided into many factors such as labor, materials, and mechanical processing. Therefore, you need to consult the relevant companies of window lifts. You can also search for related products and prices on some professional platforms such as Taobao and JD.com for reference.
Thank you again for your attention.

scan1437

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Xi'an Zhongke Alpha published on 2023-5-9 09:13 Hello, thank you very much for your attention to our company. Xi'an Zhongke Alpha Electronic Technology Co., Ltd. was established in 2016 and is headquartered in Xi'an High-tech Zone, ...

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