Magnetic Sensors

Magnetic sensors are electronic devices that convert magnetic field strength, direction, or changes into measurable electrical signals. They are widely used in industrial automation, consumer electronics, automotive electronics, and the Internet of Things. Their core operating principle is based on magnetoelectric effects (such as the Hall effect and magnetoresistance effect). They detect magnetic field parameters through sensitive elements and output corresponding voltage or current signals.

1. What are the Types of Magnetic Sensors?

Hall Effect Sensors

Detect magnetic fields by changing the Hall voltage of a semiconductor material. They offer high linearity and fast response, making them suitable for position detection (such as electric vehicle throttle control) and current measurement.

Magnetoresistive Sensors (AMR/GMR/TMR)

Utilize the property that material resistance changes with the magnetic field. AMR (anisotropic magnetoresistance) offers high sensitivity, while GMR (giant magnetoresistance) and TMR (tunnel magnetoresistance) offer higher resolution and improved interference immunity, making them suitable for hard drive read/write heads and high-precision navigation systems.

Fluxgate Sensors

Based on the principle of core saturation, they can detect weak magnetic fields (such as geomagnetic navigation). However, they are relatively large and are primarily used in military and geological exploration.

2. What are the Application Scenarios of Magnetic Sensors?

Automotive Electronics: ABS wheel speed monitoring, Electric Power Steering (EPS) angle sensing.

Smart Devices: Mobile phone electronic compass, TWS earphone flip detection.

Industry 4.0: Motor speed monitoring, logistics sorting, and positioning.

3. Key Selection Specifications for Magnetic Sensors

Sensitivity (mV/Gauss)

Operating Frequency Range

Temperature Stability (-40°C to 125°C)

Packaging (SMD/TO92, etc.)