Attributes

Brand	-
Category	Robotics / STEM Teaching Tools / Sensors
Origin	-
Model Number	KY-003 / A3144E
Operating Voltage	4.5V to 24V DC
Output Type	Digital Switch (Open Collector)
Sensing Principle	Unipolar Hall Effect
Pin Configuration	3-Pin (GND, VCC, Signal)
LED Indicator	Yes, Power On/Signal Status
Mounting Hole Diameter	3mm
PCB Dimensions	16mm x 12mm x 3mm
Compatible Platforms	Arduino, Raspberry Pi, ESP32
Application Range	Speed Detection, Position Sensing, Proximity Switching

6 reviews

Anonymous

Mar 24, 2026

Rating: 5/5

Perfect for Arduino projects

This module works flawlessly with my Arduino Uno. The detection range is consistent, and the built-in LED makes debugging very easy. Great value for the price.

Anonymous

Mar 14, 2026

Rating: 5/5

Reliable magnetic switch

Used this to create a non-contact limit switch for my 3D printer modification. It has been running for weeks without any false triggers. Highly recommended.

Anonymous

Mar 14, 2026

Rating: 5/5

Fast shipping and works great

Arrived earlier than expected. Tested immediately with a simple sketch and the output signal is crisp. No noise issues observed even with long wires.

Anonymous

Mar 10, 2026

Rating: 4/5

Solid build quality

The PCB looks clean and the soldering points are well-made. It detects standard neodymium magnets from about 1cm away, which is perfect for our conveyor belt counter.

Anonymous

Mar 10, 2026

Rating: 5/5

Great for learning electronics

Bought a pack of five for my university project. All of them worked out of the box. The voltage range is wide enough for both 5V and 12V systems.

Anonymous

Mar 06, 2026

Rating: 4/5

Good sensor, clear documentation needed

The hardware quality is solid and responds quickly to magnets. I deducted one star because the pinout wasn't clearly marked on the back, but a quick multimeter check solved it.

5 FAQ

Q: Can I use this outdoors in the rain?

A: The PCB itself is not waterproof or conformal coated. If you plan to use it outdoors, you must enclose it in a waterproof housing or apply your own conformal coating to protect the electronics from moisture.

Q: Is this a bipolar or unipolar sensor?

A: This is a unipolar Hall effect sensor. It activates when a magnetic south pole approaches the front face of the package and deactivates when the magnet is removed. It does not require a north pole to reset.

Q: What is the maximum current this sensor can switch directly?

A: The A3144E chip itself has a limited output current capability (typically around 25mA). It is designed to drive logic inputs or small LEDs. For driving motors or relays, please use an external transistor or MOSFET.

Q: How far away can it detect a standard fridge magnet?

A: Detection distance depends on the strength of the magnet. For a standard ceramic fridge magnet, the range is typically 5mm to 10mm. Stronger neodymium magnets can be detected from 15mm to 20mm away.

Q: Does this module work with 3.3V logic levels like the ESP32?

A: Yes, the module operates between 4.5V and 24V, but the output is open-collector. You can use it with 3.3V systems by powering the module at 5V and using a pull-up resistor to 3.3V on the signal line, or simply rely on the low-state grounding which is compatible.

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