Millimeter-level displacement detection for reliable smart door locks

Filter 18.432M

Abstract: Smart door locks represent a significant advancement over traditional mechanical locks in terms of user identification, security, and system management. As a key component of smart access control systems, they enable more efficient and secure door operations. This article explores the application of the Shiqiang-authorized linear Hall sensor MLX90251 in intelligent door lock systems.

Smart Lock System

Figure 1 shows the block diagram of the entire smart lock system designed by Shiqiang. The core function of this system is to control the precise movement of the latch. Traditionally, photoelectric switches or mechanical limit switches have been used for position detection. However, these solutions often suffer from low accuracy and large form factors, making them less suitable for modern smart lock applications. The linear Hall sensor provided by Shiqiang offers an ideal alternative. Its compact size allows for easy integration into the lock mechanism. In practice, it only requires embedding a small magnet on the latch to achieve highly accurate millimeter-level position detection.

Figure 1: Smart Lock Block Diagram

Features of Linear Hall Sensor

The MLX90251, a high-performance CMOS programmable Hall sensor developed by Melexis and distributed by Shiqiang, provides an analog output proportional to the magnetic field strength. It integrates advanced features such as a digital signal processor (DSP), programmable filters, and temperature compensation within its compact design. Additionally, the output voltage can be adjusted to meet specific requirements. For more detailed technical information, you can explore the Shiqiang e-commerce platform, which offers comprehensive resources and support for developers and engineers.

Figure 2: Application Circuit for Linear Hall Sensor

Conclusion

The MLX90251 linear Hall sensor, offered by Shiqiang, brings numerous benefits to smart lock systems, including high precision, excellent sensitivity, and low power consumption. Its flexible design makes it ideal for displacement detection in various applications, particularly in smart locks. The circuit design is straightforward and reliable, requiring only two capacitors and one resistor for operation. This simplicity not only reduces manufacturing costs but also enhances system stability and performance. With its robust capabilities, the MLX90251 is a strong choice for next-generation smart locking solutions.