A3144 Hall Effect Sensor – Unipolar Switch for Magnetic Sensing
A3144 Unipolar Hall Effect Sensor – Magnetic Digital Switch
The A3144 is a unipolar Hall effect switch that senses magnetic fields and provides a digital output. It is widely used in contactless switching, position detection, and speed measurement applications. Its open-collector output and wide operating voltage make it easy to integrate with microcontrollers and embedded systems.
Key Specifications
| Specification | Value |
|---|---|
| Operating Voltage | 4.5 V to 24 V DC |
| Output Type | Digital (open-collector sinking) |
| Sensing Magnetic Polarity | South pole only (unipolar) |
| Typical Operate Flux (Bop) | 35 mT (350 Gauss) |
| Maximum Output Current | 25 mA |
| Package | TO-92 (3‑pin) |
What You Can Build With This
- Contactless magnetic door/window open‑close detector
- RPM counter for motors and rotating shafts
- Proximity sensor for limit switches in automation
- Speedometer or odometer for bicycle or robotics projects
Compatibility
The A3144 works directly with any 5 V microcontroller including Arduino Uno, Nano, and Mega. It also functions with 3.3 V boards like ESP32 or Raspberry Pi Pico when using a pull‑up resistor to the respective voltage rail. A small neodymium magnet (south pole facing the branded side) is all that’s needed for activation.
Wiring Notes
Connect Vcc to 3.3–5 V, GND to ground, and the output (pin 2) to a digital input through a 10 kΩ pull‑up resistor. When a south‑pole magnet is brought near the sensor’s face, the output goes low. Many pre‑built modules already include the resistor and a status LED.
Why Buy from Compoden
Every component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-5 days. If defective on arrival, replace within 7 days.
Is this compatible with Arduino?
Yes, the A3144 outputs a digital signal that Arduino reads directly. Power it from the 5 V pin and connect the output to any digital I/O with an external or onboard pull‑up resistor.
What type of magnet should I use?
Use a standard neodymium disc magnet with the south pole facing the sensor’s labelled side. North‑pole magnets will not trigger the output.
Does this sensor need a pull‑up resistor?
The bare A3144 has an open‑collector output that requires an external pull‑up resistor (10 kΩ is typical). Complete sensor modules usually include this resistor and an indicator LED.
📦 Free Setup Handoff Document Included
Every Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.
What you can build with this
Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items