Correcting Open Loop Current Sensor Offset

Automation and Control Sensors Transducers
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Hello @bgrovenger5,

Welcome to the TechForum.

There is a small caveat when dealing with open loop Hall-effect sensors. We see this in the datasheet as:

Offset voltage value is after removal of core hysteresis.

There is often a residual magnetization of the sensor’s core that will cause this offset. Unfortunately, this is not a constant and has “memory.” For example, assume a battery charging application. The zero current flow offset will be positive after charging. Sometime later, it will be negative after discharging the battery. An overload condition will cause an especially high offset.

This topic is explored in one of my previous articles.

Recommendations:

  1. Reverse the direction of current flow and to see if the offset changes.

  2. Degauss the core.

Happy soldering,

APDahlen

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