How Hall Effect Sensors Work: Working Principle Explained
Hall effect sensors are widely used in automotive, industrial, and consumer electronics applications for measuring position, speed, current, and proximity. This guide explains the fundamental working principle of Hall effect sensors, with diagrams and comparisons to other magnetic sensors like reed switches.
What Is the Hall Effect?
The Hall effect is a phenomenon in which a voltage (called the Hall voltage) is generated perpendicular to the direction of both the current and the magnetic field in a conductor or semiconductor. This effect was discovered by Edwin Hall in 1879.
Basic diagram of the Hall effect sensor principle.
Hall Effect Sensor Working Principle
A Hall effect sensor typically consists of:
- A thin conductive plate (Hall element)
- Power supply terminals
- Output terminals
- Magnetic field input
When current flows through the conductive plate and a magnetic field is applied perpendicular to the current, a voltage difference is generated at the sides of the plate. This voltage is proportional to the strength of the magnetic field.
Illustration of how Hall sensors detect magnetic fields.
Video: How Hall Effect Sensors Work
Hall Effect Sensor vs Reed Switch
Both Hall effect sensors and reed switches are used for magnetic detection. Here's a comparison:
| Feature | Hall Effect Sensor | Reed Switch |
|---|---|---|
| Sensitivity | High, continuous | On/off only |
| Durability | Solid-state, high durability | Mechanical contacts, lower lifespan |
| Output | Analog or digital | Digital only |
Key Use Cases
- Automotive: Crankshaft and camshaft position sensors
- Industrial: Motor speed monitoring
- Medical: Non-invasive position detection
Common Variants of Hall Sensors
FAQs
How does a Hall effect sensor work?
It detects magnetic fields by generating a voltage that varies with the field strength perpendicular to the current flow.
What is the output of a Hall effect sensor?
Depending on the type, it can produce analog or digital signals.
Can a Hall effect sensor measure current?
Yes, with a magnetic core, it can measure DC or AC current flow.
For more sensor types, visit the Hall Effect Sensor Types Overview page.
