Power Budget per Reading across Competing Sensing Principles
Sensing power budgets depend on physical excitation energy, analog settling delays, and converter sampling overhead across operating duty cycles.
Open-Loop Hall Effect
Magnetic Flux
Current measurement without physical contact relies on the interaction between a magnetic field and a semiconductor material. An open-loop hall effect sensor detects the strength of the flux generated by a conductor and converts it into a proportional voltage. The absence of a feedback winding makes this architecture compact and cost effective for high volume industrial applications.
Linearity Error
The output follows the magnetic field intensity which is subject to the saturation limits of the core material. An open-loop hall effect device typically achieves an accuracy within 1 to 2 percent of the full scale. Unlike closed loop systems, the gain is directly tied to the sensitivity of the Hall element and the core permeability.
Temperature Drift
Semiconductor properties change as the environment warms or cools, shifting both the zero point and the sensitivity. Because an open-loop hall effect transducer lacks a secondary compensation circuit, it is vulnerable to offset errors that vary with the ambient air. High quality modules include internal thermistors to provide basic correction.
Without such measures, the accuracy degrades at the edges of the operating range.
Reaction Time
The response speed is generally fast because the signal does not wait for a compensation coil to settle. This makes open-loop hall effect technology suitable for basic overcurrent protection.