Phone systems used in public places, especially in high-traffic areas like subway stations, bus stops, schools, and hospitals, face increased security risks and the risk of vandalism. To address this, vandal-resistant telephones have emerged. Compared to ordinary telephones, these phones are designed to be more robust and durable, with a focus on resistance to disassembly, vandalism, and environmental stress. This article will focus on their anti-tampering design and surge protection.

Anti-tampering is a core feature of vandal-resistant telephones. Traditional telephones are easily disassembled or vandalized in public places, resulting in communication interruptions and device damage. To prevent this, vandal-resistant telephones incorporate the following design measures:

• Thickened Housing Material

  Vandal-resistant telephones typically use high-strength metal materials (such as stainless steel or aluminum alloy) for their housings, which are typically several times thicker than those of ordinary phones. This material not only withstands external impact but also withstands harsh weather conditions such as wind, rain, and high and low temperatures.

• Tamper-resistant screw design

  The screws on the phone casing are designed to be tamper-resistant, such as with dedicated tamper-resistant screws or concealed screws. Even if someone attempts to remove the phone with a standard screwdriver, it's difficult to open the casing, effectively preventing damage to the device or unauthorized tampering with the internal wiring.

• Modular internal structure

  The internal circuit modules are typically secured with snaps or threads and equipped with additional protective panels. Even if the casing is damaged, the core communication module remains protected, ensuring the phone continues to function.

• Vandal-resistant handset and buttons

  The phone's handset and buttons are also specially designed, such as using high-strength rubber or metal buttons to resist knocks, cutting, and pulling. Furthermore, the handset cord is typically made of steel-wire-wrapped, strain-resistant material to prevent unauthorized unplugging and damage.

Public phones are not only subject to the risk of vandalism but are also susceptible to electrical interference such as lightning strikes and power grid fluctuations. Therefore, surge protection is a key design feature of vandal-resistant phones:

• Built-in Surge Protector

  Phone devices are often equipped with a surge protector (SPD). In the event of a lightning strike or a sudden voltage surge, this device diverts excess voltage to ground, protecting internal circuits from damage.

• Insulation and Grounding Design

  Vandal-resistant phones typically utilize high-insulation materials and ensure that the housing and circuit boards are properly grounded. Even in the event of an external surge or electrostatic discharge, the device effectively diverts the hazardous current to ground, ensuring safe operation.

• Multi-Level Overvoltage Protection

  High-end vandal-resistant phones feature multi-level voltage protection, such as overvoltage protection devices installed at both the power input and communication lines, preventing damage from surges at various levels.

The tamper-resistant design and surge protection make vandal-resistant phones widely used in public safety and critical communications environments. Whether in subway stations, tunnels, public squares, campuses, or industrial parks, these phones ensure long-term stable operation and reduce maintenance costs. Their rugged design also extends device life and reduces communication interruptions caused by vandalism.