Today’s engineers who design building and home security products need to ensure that their devices are not creating a false sense of security for their customers. An essential step to improving overall reliability and safety is understanding the protection and sensing components required to comply with applicable standards to ensure safe, robust, and reliable products.To get more news about commercial safe locks, you can visit securamsys.com official website.

The smart locks market alone is seeing high growth and innovation, with global growth expected to have a CAGR of 25 percent and unit growth expanding to about 23 million units in 20241. At approximately 70 percent, residential market represents most of the growth. The increased awareness of a need for personal security will drive global growth of window and door sensors as well, especially in developing economies. Shipments are expected to increase at a CAGR of around nine percent, to around 465 million units in 20242.

Protecting Smart Lock Designs
Smart locks consist of a manual access keypad, a smartphone wireless protocol link for access through a software application, a sensor that monitors the door handle position, door lock/unlock actuators, and sensing to detect any attempts to circumvent the lock. Figure 1 provides an example smart door lock with recommended circuit protection and sensing to ensure reliable operation. Figure 2 shows a detailed block diagram of a smart lock with the suggested protection and sensing components placement.

The primary danger to smart lock electronics is electrostatic discharge (ESD). The wireless and user interfaces are susceptible to ESD from end-users.

The User Interface provides a keypad that a person must contact with their finger to enter the pre-programmed access code. All users are a source of ESD, particularly in very dry environments. Designers should protect the User Interface circuitry from ESD to avoid damage to sensitive electronics.
Consider using a transient voltage suppressor (TVS) diode or TVS diode array for ESD protection. TVS diodes are Zener diodes that utilize silicon avalanche technology that provides a minimum protection level of ±15 kV of ESD voltage. A TVS diode array with up to six Zener diodes can protect five signal lines and provide a ground reference (Figure 3). In one space-saving component in an 0402 surface-mount package, a TVS diode array can protect up to five lines. The impact on the circuit is minimal as TVS diode arrays have a leakage current of only 1 µA. If more ESD protection is needed, individual diodes can provide ESD protection for the individual signal lines. A single TVS diode (Figure 4) withstands as much as ±30 kV. Regardless of the configuration used, place the TVS diodes as close to the circuit’s input as possible to prevent any ESD transient from penetrating the circuitry.

The Wireless Interface links to a cellular network, wireless LAN, or WiFi network to communicate with smartphones or other networked devices. Because it is exposed to the external environment, the Wireless Interface requires ESD protection. A polymer ESD suppressor is the recommended component. The benefit of a polymer ESD suppressor is its ability to respond to and absorb any ESD transients while having very little impact on the Wireless Interface output's characteristic impedance. Polymer ESD suppressors withstand a direct contact ±8 kV ESD and an air strike ±15 kV. Typical capacitance is a low 0.06 pF, with a very fast response time to a transient of under 1 ns. Be sure the ESD suppressor is as close to the input antenna's connector as possible. Figure 5 shows two configurations for bi-directional polymer ESD suppressors.

Ensuring doors are completely seated in their door frames requires sensors at each location for detection. Consider a reed switch with a magnetic actuator as a low-power sensing solution for battery-operated smart locks. Reed switches do not require drive power, can switch 10 W with ratings up to 0.5 A or up to 200 V, and are hermetically sealed for long life in outdoor environments. Reed switches are well-suited for use in low-voltage controller circuits. Surface mount versions are available for automated printed circuit board assembly.