Magnetic Tamper Detection Reference Design Using Low Power Hall Effect Sensors

Magnetic tampering can disable any transformer in an energy metering system, which may result in the system not being properly powered or the energy being consumed by the load being recorded incorrectly. This design enables a Class 0.2 three-phase energy metering system that uses Hall sensors to detect magnetic tampering. Magnetic tamper detection is enabled when operating from primary and backup power. Various methods are employed to reduce the current consumption of Hall sensors in order to extend battery life when operating from backup power.

characteristic

• ● Bop =±6.9 mT, sensor Brp =±3.5mT
• ● Support backup power supply
• ● Software power duty cycle reduces current consumption to less than 2µA per sensor
• ● Three-phase energy measurement exceeds ANSI and IEC Class 0.2 accuracy requirements
• ● TI Energy Library firmware calculates all energy metering parameters, including active and reactive power, active and reactive energy, root mean square (RMS) current and voltage, power factor, and line frequency